WO2025019888A1 - Forehead cooling systems - Google Patents

Abstract

The technology relates to forehead cooling systems configured for use with patient interfaces to aid in treatment of sleeping and breathing disorders. Examples of the technology include fluid cooling systems, such as air and water cooling. Other examples use phase change materials, and thermoelectric coolers. In some examples the forehead cooling systems may be attached to a positioning and stabilising structure.

Description

FOREHEAD COOLING SYSTEMS

1 CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Australian Provisional Patent Application No. 2023902322, filed 21 July 2023, the contents of which is herein incorporated by reference in its entirety.

2 BACKGROUND OF THE TECHNOLOGY

2.1 FIELD OF THE TECHNOLOGY

[0002] The present technology relates to one or more of the screening, diagnosis, monitoring, treatment, prevention and amelioration of respiratory-related disorders. The present technology also relates to medical devices or apparatus, and their use.

2.2 DESCRIPTION OF THE RELATED ART

2.2.1 Human Respiratory System and its Disorders

[0003] The respiratory system of the body facilitates gas exchange. The nose and mouth form the entrance to the airways of a patient.

[0004] The airways include a series of branching tubes, which become narrower, shorter and more numerous as they penetrate deeper into the lung. The prime function of the lung is gas exchange, allowing oxygen to move from the inhaled air into the venous blood and carbon dioxide to move in the opposite direction. The trachea divides into right and left main bronchi, which further divide eventually into terminal bronchioles. The bronchi make up the conducting airways, and do not take part in gas exchange. Further divisions of the airways lead to the respiratory bronchioles, and eventually to the alveoli. The alveolated region of the lung is where the gas exchange takes place, and is referred to as the respiratory zone. See “ Respiratory Physiology” , by John B. West, Lippincott Williams & Wilkins, 9th edition published 2012.

[0005] A range of respiratory disorders exist. Certain disorders may be characterised by particular events, e.g. apneas, hypopneas, and hyperpneas.

[0006] Examples of respiratory disorders include Obstructive Sleep Apnea

(OSA), Cheyne-Stokes Respiration (CSR), respiratory insufficiency, Obesity Hypoventilation Syndrome (OHS), Chronic Obstructive Pulmonary Disease (COPD), Neuromuscular Disease (NMD) and Chest wall disorders. [0007] Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing (SDB), is characterised by events including occlusion or obstruction of the upper air passage during sleep. It results from a combination of an abnormally small upper airway and the normal loss of muscle tone in the region of the tongue, soft palate and posterior oropharyngeal wall during sleep. The condition causes the affected patient to stop breathing for periods typically of 30 to 120 seconds in duration, sometimes 200 to 300 times per night. It often causes excessive daytime somnolence, and it may cause cardiovascular disease and brain damage. The syndrome is a common disorder, particularly in middle aged overweight males, although a person affected may have no awareness of the problem, e.g. see US Patent No. 4,944,310 (Sullivan).

[0008] Cheyne-Stokes Respiration (CSR) is another form of sleep disordered breathing. CSR is a disorder of a patient's respiratory controller in which there are rhythmic alternating periods of waxing and waning ventilation known as CSR cycles. CSR is characterised by repetitive de-oxygenation and re-oxygenation of the arterial blood. It is possible that CSR is harmful because of the repetitive hypoxia. In some patients CSR is associated with repetitive arousal from sleep, which causes severe sleep disruption, increased sympathetic activity, and increased afterload, e.g. see US Patent No. 6,532,959 (Berthon-Jones).

[0009] Respiratory failure is an umbrella term for respiratory disorders in which the lungs are unable to inspire sufficient oxygen or exhale sufficient CO2 to meet the patient’s needs. Respiratory failure may encompass some or all of the following disorders.

[0010] A patient with respiratory insufficiency (a form of respiratory failure) may experience abnormal shortness of breath on exercise.

[0011] Obesity Hypoventilation Syndrome (OHS) is defined as the combination of severe obesity and awake chronic hypercapnia, in the absence of other known causes for hypoventilation. Symptoms include dyspnea, morning headache and excessive daytime sleepiness.

[0012] Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a group of lower airway diseases that have certain characteristics in common. These include increased resistance to air movement, extended expiratory phase of respiration, and loss of the normal elasticity of the lung. Examples of COPD are emphysema and chronic bronchitis. COPD is caused by chronic tobacco smoking (primary risk factor), occupational exposures, air pollution and genetic factors. Symptoms include: dyspnea on exertion, chronic cough and sputum production. [0013] Neuromuscular Disease (NMD) is a broad term that encompasses many diseases and ailments that impair the functioning of the muscles either directly via intrinsic muscle pathology, or indirectly via nerve pathology. Some NMD patients are characterised by progressive muscular impairment leading to loss of ambulation, being wheelchair-bound, swallowing difficulties, respiratory muscle weakness and, eventually, death from respiratory failure. Neuromuscular disorders can be divided into rapidly progressive and slowly progressive: (i) Rapidly progressive disorders: Characterised by muscle impairment that worsens over months and results in death within a few years (e.g. Amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) Variable or slowly progressive disorders: Characterised by muscle impairment that worsens over years and only mildly reduces life expectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic muscular dystrophy). Symptoms of respiratory failure in NMD include: increasing generalised weakness, dysphagia, dyspnea on exertion and at rest, fatigue, sleepiness, morning headache, and difficulties with concentration and mood changes.

[0014] Chest wall disorders are a group of thoracic deformities that result in inefficient coupling between the respiratory muscles and the thoracic cage. The disorders are usually characterised by a restrictive defect and share the potential of long term hypercapnic respiratory failure. Scoliosis and/or kyphoscoliosis may cause severe respiratory failure. Symptoms of respiratory failure include: dyspnea on exertion, peripheral oedema, orthopnea, repeated chest infections, morning headaches, fatigue, poor sleep quality and loss of appetite.

[0015] A range of therapies have been used to treat or ameliorate such conditions. Furthermore, otherwise healthy individuals may take advantage of such therapies to prevent respiratory disorders from arising. However, these have a number of shortcomings.

2.2.2 Therapies

[0016] Various respiratory therapies, such as Positive Airway Pressure (PAP) therapy including Continuous Positive Airway Pressure (CPAP) therapy, Non- invasive ventilation (NIV), Invasive ventilation (IV), and High Flow Therapy (HFT) have been used to treat one or more of the above respiratory disorders. 2.2.2.1 Respiratory pressure therapies

[0017] Respiratory pressure therapy is the application of a supply of air to an entrance to the airways at a controlled target pressure that is nominally positive with respect to atmosphere throughout the patient’s breathing cycle (in contrast to negative pressure therapies such as the tank ventilator or cuirass).

[0018] Continuous Positive Airway Pressure (CPAP) therapy has been used to treat Obstructive Sleep Apnea (OSA). The mechanism of action is that continuous positive airway pressure acts as a pneumatic splint and may prevent upper airway occlusion, such as by pushing the soft palate and tongue forward and away from the posterior oropharyngeal wall. Treatment of OSA by CPAP therapy may be voluntary, and hence patients may elect not to comply with therapy if they find devices used to provide such therapy one or more of: uncomfortable, difficult to use, expensive and aesthetically unappealing.

[0019] Non-invasive ventilation (NIV) provides ventilatory support to a patient through the upper airways to assist the patient breathing and/or maintain adequate oxygen levels in the body by doing some or all of the work of breathing. The ventilatory support is provided via a non-invasive patient interface. NIV has been used to treat CSR and respiratory failure, in forms such as OHS, COPD, NMD and Chest Wall disorders. In some forms, the comfort and effectiveness of these therapies may be improved.

[0020] Invasive ventilation (IV) provides ventilatory support to patients that are no longer able to effectively breathe themselves and may be provided using a tracheostomy tube or endotracheal tube. In some forms, the comfort and effectiveness of these therapies may be improved.

2.2.2.2 Flow therapies

[0021] Not all respiratory therapies aim to deliver a prescribed therapeutic pressure. Some respiratory therapies aim to deliver a prescribed respiratory volume, by delivering an inspiratory flow rate profile over a targeted duration, possibly superimposed on a positive baseline pressure. In other cases, the interface to the patient’s airways is ‘open’ (unsealed) and the respiratory therapy may only supplement the patient’s own spontaneous breathing with a flow of conditioned or enriched gas. In one example, High Flow therapy (HFT) is the provision of a continuous, heated, humidified flow of air to an entrance to the airway through an unsealed or open patient interface at a “treatment flow rate” that may be held approximately constant throughout the respiratory cycle. The treatment flow rate is nominally set to exceed the patient’s peak inspiratory flow rate. HFT has been used to treat OSA, CSR, respiratory failure, COPD, and other respiratory disorders. One mechanism of action is that the high flow rate of air at the airway entrance improves ventilation efficiency by flushing, or washing out, expired CO2 from the patient’s anatomical deadspace. Hence, HFT is thus sometimes referred to as a deadspace therapy (DST). Other benefits may include the elevated warmth and humidification (possibly of benefit in secretion management) and the potential for modest elevation of airway pressures. As an alternative to constant flow rate, the treatment flow rate may follow a profile that varies over the respiratory cycle.

[0022] Another form of flow therapy is long-term oxygen therapy (LTOT) or supplemental oxygen therapy. Doctors may prescribe a continuous flow of oxygen enriched air at a specified oxygen concentration (from 21%, the oxygen fraction in ambient air, to 100%) at a specified flow rate (e.g., 1 litre per minute (LPM), 2 LPM, 3 LPM, etc.) to be delivered to the patient’s airway.

2.2.3 Respiratory Therapy Systems

[0023] These respiratory therapies may be provided by a respiratory therapy system or device. Such systems and devices may also be used to screen, diagnose, or monitor a condition without treating it.

[0024] A respiratory therapy system may comprise a Respiratory Pressure Therapy Device (RPT device), an air circuit, a humidifier, a patient interface, an oxygen source, and data management.

2.2.3.1 Patient Interface

[0025] A patient interface may be used to interface respiratory equipment to its wearer, for example by providing a flow of air to an entrance to the airways. The flow of air may be provided via a mask to the nose and/or mouth, a tube to the mouth or a tracheostomy tube to the trachea of a patient. Depending upon the therapy to be applied, the patient interface may form a seal, e.g., with a region of the patient's face, to facilitate the delivery of gas at a pressure at sufficient variance with ambient pressure to effect therapy, e.g., at a positive pressure of about 10 cmH20 relative to ambient pressure. For other forms of therapy, such as the delivery of oxygen, the patient interface may not include a seal sufficient to facilitate delivery to the airways of a supply of gas at a positive pressure of about 10 cmH20. For flow therapies such as nasal HFT, the patient interface is configured to insufflate the nares but specifically to avoid a complete seal. One example of such a patient interface is a nasal cannula. [0026] Certain mask systems may be functionally unsuitable for the present field. For example, purely ornamental masks may be unable to maintain a suitable pressure. Mask systems used for underwater swimming or diving may be configured to guard against ingress of water from an external higher pressure, but not to maintain air internally at a higher pressure than ambient.

[0027] Certain masks may be clinically unfavourable for the present technology e.g. if they block airflow via the nose and only allow it via the mouth.

[0028] Certain masks may be uncomfortable or impractical for the present technology if they require a patient to insert a portion of a mask structure in their mouth to create and maintain a seal via their lips.

[0029] Certain masks may be impractical for use while sleeping, e.g. for sleeping while lying on one’s side in bed with a head on a pillow.

[0030] Certain masks may cause some patients a feeling of claustrophobia, unease and/or may feel overly obtrusive.

[0031] The design of a patient interface presents a number of challenges. The face has a complex three-dimensional shape. The size and shape of noses and heads varies considerably between individuals. Since the head includes bone, cartilage and soft tissue, different regions of the face respond differently to mechanical forces. The jaw or mandible may move relative to other bones of the skull. The whole head may move during the course of a period of respiratory therapy.

[0032] Consequently, some masks suffer from being obtrusive, aesthetically undesirable, costly, poorly fitting, difficult to use, and/or uncomfortable especially when worn for long or when a patient is unfamiliar with a system. Wrongly sized masks can give rise to reduced compliance, reduced comfort and poorer patient outcomes. Masks designed solely for aviators, masks designed as part of personal protection equipment (e.g. filter masks), SCUBA masks, or for the administration of anaesthetics may be tolerable for their original application, but nevertheless such masks may be undesirably uncomfortable to be worn for extended periods of time, e.g., several hours. This discomfort may lead to a reduction in patient compliance with therapy, especially if the mask is to be worn during sleep.

[0033] CPAP therapy is highly effective to treat certain respiratory disorders, provided patients comply with therapy. If a mask is uncomfortable, or difficult to use a patient may not comply with therapy. Since it is often recommended that a patient regularly wash their mask, if a mask is difficult to clean (e.g., difficult to assemble or disassemble), patients may not clean their mask and this may impact on patient compliance.

[0034] While a mask for other applications (e.g. aviators) may not be suitable for use in treating sleep disordered breathing, a mask designed for use in treating sleep disordered breathing may be suitable for other applications.

[0035] For these reasons, patient interfaces for delivery of CPAP during sleep form a distinct field.

2.2.3.1.1 Seal-forming structure

[0036] Patient interfaces may include a seal-forming structure. Since it is in direct contact with the patient’s face, the shape and configuration of the seal-forming structure can have a direct impact the effectiveness and comfort of the patient interface.

[0037] A patient interface may be partly characterised according to the design intent of where the seal-forming structure is to engage with the face in use. In one form of patient interface, a seal-forming structure may comprise a first sub-portion to form a seal around the left naris and a second sub-portion to form a seal around the right naris. In one form of patient interface, a seal-forming structure may comprise a single element that surrounds both nares in use. Such single element may be designed to for example overlay an upper lip region and a nasal bridge region of a face. In one form of patient interface a seal-forming structure may comprise an element that surrounds a mouth region in use, e.g. by forming a seal on a lower lip region of a face. In one form of patient interface, a seal-forming structure may comprise a single element that surrounds both nares and a mouth region in use. These different types of patient interfaces may be known by a variety of names by their manufacturer including nasal masks, full-face masks, nasal pillows, nasal puffs and oro-nasal masks.

[0038] A seal-forming structure that may be effective in one region of a patient’s face may be inappropriate in another region, e.g. because of the different shape, structure, variability and sensitivity regions of the patient’s face. For example, a seal on swimming goggles that overlays a patient’s forehead may not be appropriate to use on a patient’s nose. [0039] Certain seal-forming structures may be designed for mass manufacture such that one design is able to fit and be comfortable and effective for a wide range of different face shapes and sizes. To the extent to which there is a mismatch between the shape of the patient’s face, and the seal-forming structure of the mass- manufactured patient interface, one or both must adapt in order for a seal to form. [0040] One type of seal-forming structure extends around the periphery of the patient interface, and is intended to seal against the patient's face when force is applied to the patient interface with the seal-forming structure in confronting engagement with the patient's face. The seal-forming structure may include an air or fluid filled cushion, or a moulded or formed surface of a resilient seal element made of an elastomer such as a rubber. With this type of seal-forming structure, if the fit is not adequate, there will be gaps between the seal-forming structure and the face, and additional force will be required to force the patient interface against the face in order to achieve a seal.

[0041] Another type of seal-forming structure incorporates a flap seal of thin material positioned about the periphery of the mask so as to provide a self-sealing action against the face of the patient when positive pressure is applied within the mask. Like the previous style of seal forming portion, if the match between the face and the mask is not good, additional force may be required to achieve a seal, or the mask may leak. Furthermore, if the shape of the seal-forming structure does not match that of the patient, it may crease or buckle in use, giving rise to leaks.

[0042] Another type of seal-forming structure may comprise a friction-fit element, e.g. for insertion into a naris, however some patients find these uncomfortable.

[0043] Another form of seal-forming structure may use adhesive to achieve a seal. Some patients may find it inconvenient to constantly apply and remove an adhesive to their face.

[0044] A range of patient interface seal-forming structure technologies are disclosed in the following patent applications: WO 1998/004310; WO 2006/074513; WO 2010/135785.

[0045] One form of nasal pillow is found in the Adam Circuit manufactured by Puritan Bennett. Another nasal pillow, or nasal puff is the subject of US Patent 4,782,832 (Trimble et al.), assigned to Puritan-Bennett Corporation. [0046] ResMed Inc. has manufactured the following products that incorporate nasal pillows: SWIFTTM nasal pillows mask, SWIFTTM II nasal pillows mask, SWIFTTM LT nasal pillows mask, SWIFTTM FX nasal pillows mask and MIRAGE LIBERTYTM full-face mask. The following patent applications describe examples of nasal pillows masks: International Patent Application WO 2004/073778 (describing amongst other things aspects of the SWIFTTM nasal pillows mask), US Patent Application 2009/0044808 (describing amongst other things aspects of the SWIFTTM LT nasal pillows mask); International Patent Applications WO 2005/063328 and WO 2006/130903 (describing amongst other things aspects of the MIRAGE LIBERTYTM full-face mask); International Patent Application WO 2009/052560 (describing amongst other things aspects of the SWIFTTM FX nasal pillows mask).

2.2.3.1.2 Positioning and Stabilising Structure

[0047] A seal-forming structure of a patient interface used for positive air pressure therapy is subject to the corresponding force of the air pressure to disrupt a seal. Thus a variety of techniques have been used to position the seal-forming structure, and to maintain it in sealing relation with the appropriate portion of the face. Several factors may be considered when comparing different positioning and stabilising techniques. These include: how effective the technique is at maintaining the seal-forming structure in the desired position and in sealed engagement with the face during use of the patient interface; how comfortable the interface is for the patient; whether the patient feels intrusiveness and/or claustrophobia when wearing the patient interface; and aesthetic appeal.

[0048] One technique is the use of adhesives, e.g. see US Patent Application Publication No. US 2010/0000534. However, the use of adhesives may be uncomfortable for some.

[0049] Another technique is the use of one or more straps and/or stabilising harnesses. Many such harnesses suffer from being one or more of ill-fitting, bulky, uncomfortable and awkward to use.

2.2.3.1.3 Pressurised Air Conduit

[0050] In one type of treatment system, a flow of pressurised air is provided to a patient interface through a conduit in an air circuit that fluidly connects to the patient interface at a location that is in front of the patient’s face when the patient interface is positioned on the patient’s face during use. The conduit may extend from the patient interface forwards away from the patient’s face. 2.2.3.1.4 Pressurised Air Conduit used for Positioning / Stabilising the Seal- Forming Structure

[0051] Another type of treatment system comprises a patient interface in which a tube that delivers pressurised air to the patient’s airways also functions as part of the headgear to position and stabilise the seal-forming portion of the patient interface at the appropriate part of the patient’s face. This type of patient interface may be referred to as having “conduit headgear” or “headgear tubing”. Such patient interfaces allow the conduit in the air circuit providing the flow of pressurised air from a respiratory pressure therapy (RPT) device to connect to the patient interface in a position other than in front of the patient’s face. One example of such a treatment system is disclosed in US Patent Publication No. US 2007/0246043, the contents of which are incorporated herein by reference, in which the conduit connects to a tube in the patient interface through a port positioned in use on top of the patient’s head.

[0052] It is desirable for patient interfaces incorporating headgear tubing to be comfortable for a patient to wear over a prolonged duration when the patient is asleep, form an air-tight and stable seal with the patient’s face, while also able to fit a range of patient head shapes and sizes.

2.2.3.2 Respiratory Pressure Therapy (RPT) Device

[0053] A respiratory pressure therapy (RPT) device may be used individually or as part of a system to deliver one or more of a number of therapies described above, such as by operating the device to generate a flow of air for delivery to an interface to the airways. The flow of air may be pressure-controlled (for respiratory pressure therapies) or flow-controlled (for flow therapies such as HFT). Thus RPT devices may also act as flow therapy devices. Examples of RPT devices include a PAP device and a ventilator.

[0054] Air pressure generators are known in a range of applications, e.g. industrial-scale ventilation systems. However, air pressure generators for medical applications have particular requirements not fulfilled by more generalised air pressure generators, such as the reliability, size and weight requirements of medical devices. In addition, even devices designed for medical treatment may suffer from shortcomings, pertaining to one or more of: comfort, noise, ease of use, efficacy, size, weight, manufacturability, cost, and reliability.

[0055] An example of the special requirements of certain RPT devices is acoustic noise. [0056] Table of noise output levels of prior RPT devices (one specimen only, measured using test method specified in ISO 3744 in CPAP mode at 10 cmH20).

[0057] One known RPT device used for treating sleep disordered breathing is the S9 Sleep Therapy System, manufactured by ResMed Inc. Another example of an RPT device is a ventilator. Ventilators such as the ResMed Stellar™ Series of Adult and Paediatric Ventilators may provide support for invasive and non-invasive nondependent ventilation for a range of patients for treating a number of conditions such as but not limited to NMD, OHS and COPD.

[0058] The ResMed Elisee™ 150 ventilator and ResMed VS III™ ventilator may provide support for invasive and non-invasive dependent ventilation suitable for adult or paediatric patients for treating a number of conditions. These ventilators provide volumetric and barometric ventilation modes with a single or double limb circuit.

RPT devices typically comprise a pressure generator, such as a motor-driven blower or a compressed gas reservoir, and are configured to supply a flow of air to the airway of a patient. In some cases, the flow of air may be supplied to the airway of the patient at positive pressure. The outlet of the RPT device is connected via an air circuit to a patient interface such as those described above.

[0059] The designer of a device may be presented with an infinite number of choices to make. Design criteria often conflict, meaning that certain design choices are far from routine or inevitable. Furthermore, the comfort and efficacy of certain aspects may be highly sensitive to small, subtle changes in one or more parameters.

2.2.3.3 Air circuit

[0060] An air circuit is a conduit or a tube constructed and arranged to allow, in use, a flow of air to travel between two components of a respiratory therapy system such as the RPT device and the patient interface. In some cases, there may be separate limbs of the air circuit for inhalation and exhalation. In other cases, a single limb air circuit is used for both inhalation and exhalation.

2.2.3.4 Humidifier

[0061] Delivery of a flow of air without humidification may cause drying of airways. The use of a humidifier with an RPT device and the patient interface produces humidified gas that minimizes drying of the nasal mucosa and increases patient airway comfort. In addition, in cooler climates, warm air applied generally to the face area in and about the patient interface is more comfortable than cold air.

2.2.3.5 Vent technologies

[0062] Some forms of treatment systems may include a vent to allow the washout of exhaled carbon dioxide. The vent may allow a flow of gas from an interior space of a patient interface, e.g., the plenum chamber, to an exterior of the patient interface, e.g., to ambient.

[0063] The vent may comprise an orifice and gas may flow through the orifice in use of the mask. Many such vents are noisy. Others may become blocked in use and thus provide insufficient washout. Some vents may be disruptive of the sleep of a bed partner 1100 of the patient 1000, e.g. through noise or focussed airflow.

[0064] ResMed Inc. has developed a number of improved mask vent technologies, e.g. see International Patent Application Publication No. WO 1998/034665; International Patent Application Publication No. WO 2000/078381; US Patent No. 6,581,594; US Patent Application Publication No. US 2009/0050156; US Patent Application Publication No. 2009/0044808.

[0065] Table of noise of prior masks (ISO 17510-2:2007, 10 cmH20 pressure at Im)

[0066] (* one specimen only, measured using test method specified in ISO 3744 in CPAP mode at 10 cmH20)

[0067] Sound pressure values of a variety of objects are listed below

3 BRIEF SUMMARY OF THE TECHNOLOGY

[0068] The present technology is directed towards providing medical devices used in the screening, diagnosis, monitoring, amelioration, treatment, or prevention of respiratory disorders having one or more of improved comfort, cost, efficacy, ease of use and manufacturability.

[0069] A first aspect of the present technology relates to apparatus used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.

[0070] Another aspect of the present technology relates to methods used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.

[0071] An aspect of certain forms of the present technology is to provide methods and/or apparatus that improve the compliance of patients with respiratory therapy. [0072] One form of the present technology comprises a positioning and stabilising structure configured to provide a force to hold the seal-forming structure in a therapeutically effective position on the patient’s head. The positioning and stabilising structure includes at least one strap.

[0073] One form of the present technology comprises a patient interface comprising a plenum chamber, a seal-forming structure, and a positioning and stabilising structure.

[0074] One form of the present technology comprises patient interface comprising a plenum chamber pressurisable to a therapeutic pressure of at least 4 cmH20 above ambient air pressure. The plenum chamber includes at least one plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient. The patient interface also comprises a seal-forming structure that is constructed and arranged to form a seal with a region of the patient’s face surrounding an entrance to the patient’s airways. The seal-forming structure has a hole therein such that the flow of air at said therapeutic pressure is delivered to at least an entrance to the patient’s nares. The seal-forming structure is constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient’s respiratory cycle in use. The patient interface also comprises a positioning and stabilising structure to provide a force to hold the seal-forming structure in a therapeutically effective position on the patient’s head. [0075] Another aspect of one form of the present technology is a series of modular elements that may be interconnected in order to form different styles of patient interfaces.

[0076] In one form, there are at least two versions or styles of each modular element. The versions or styles may be interchangeably used with one another in order to form different modular assemblies.

[0077] One form of the present technology comprises a patient interface configured to deliver a flow of breathable gas to a patient for treatment of a respiratory disorder, the patient interface comprising: a plenum chamber pressurisable to a therapeutic pressure of at least 4 cmH20 above ambient air pressure throughout a patient’s respiratory cycle in use, the plenum chamber comprising: a seal-forming structure constructed and arranged to form a seal with a region of the patient’s face surrounding at least one entrance to the patient’s airways, a positioning and stabilising structure configured to maintain the seal-forming structure in position on the patient’s face in use, and a forehead cooling system, configured to cool the forehead of the patient in use.

[0078] In examples of the technology, the patient interface may be configured to connect to an air circuit to receive the flow of breathable gas from a flow generator. [0079] In examples of the technology, the forehead cooling system may be configured to direct a portion of the flow of breathable gas onto the forehead of the patient in use.

[0080] In examples of the technology, the forehead cooling system may be a conduit configured to direct a flow of breathable gas onto the forehead of the patient in use.

[0081] In examples of the technology, the conduit may be fluidly connected to the plenum chamber, and may be configured to direct breathable gas out of the plenum chamber, towards the forehead of the patient.

[0082] In examples of the technology, the conduit may be connected to an air circuit configured to connect to a connection port on the patient interface.

[0083] In examples of the technology, the conduit may be provided in the positioning and stabilising structure.

[0084] In examples of the technology, a first conduit may be fluidly connected to a first side of the positioning and stabilising structure in a region superior to the eyes of the patient. [0085] In examples of the technology, a second conduit may be positioned on a second, opposing side of the positioning and stabilising structure in a region superior to the eyes of the patient.

[0086] In examples of the technology, the first conduit may be fluidly connected to the second conduit by a semi permeable material configured to vent a flow of breathable gas onto the forehead of the patient.

[0087] In examples of the technology, the forehead cooling system may be positioned in contact with the forehead of the patient in use.

[0088] In examples of the technology, the forehead cooling system may comprise a fluid reservoir.

[0089] In examples of the technology, the fluid reservoir may comprise any one or more of: water, oil, a gel, or sodium polyacrylate.

[0090] In examples of the technology, the patient interface may further comprise a pump configured to cause a fluid flow within the fluid reservoir.

[0091] In examples of the technology, the forehead cooling system may comprise a thermoelectric cooler.

[0092] In examples of the technology, the forehead cooling system may comprise a thermal interface material which is positioned in contact with the forehead of the patient in use.

[0093] In examples of the technology, the forehead cooling system may comprise a heatsink.

[0094] Another aspect of one form of the present technology is a method of controlling a forehead cooling system comprising the steps of: A) monitoring the temperature of the forehead of a patient; B) activating a forehead cooler if the temperature of the forehead is greater than a first predetermined threshold C) deactivating the forehead cooler if the temperature of the forehead is lesser than a second predetermined threshold.

[0095] In examples of the technology, the first predetermined threshold may be between 20 and 30 degrees Celsius.

[0096] In examples of the technology, the first predetermined threshold may be substantially equal to 25 degrees Celsius.

[0097] In examples of the technology, the second predetermined threshold may be between 15 and 20 degrees Celsius. [0098] In examples of the technology, the second predetermined threshold may be substantially equal to 18 degrees Celsius.

[0099] In examples of the technology, the forehead cooler may comprise a first active mode and a second active mode, wherein the first active mode provides a first rate of cooling, and the second active mode provides a second rate of cooling which is less than the first active mode.

[0100] In examples of the technology, the forehead cooling system may be configured to switch from the first active mode to the second active mode when the forehead temperature is less than a third predetermined threshold, and from the second active mode to the first active mode when the forehead temperature is above the third predetermined threshold.

[0101] In examples of the technology, the third predetermined threshold may be between 20 and 22 degrees.

[0102] In examples of the technology, the forehead cooling system may only active during a period of sleep onset, and is inactive when the patient is detected to be asleep.

[0103] In examples of the technology, the forehead cooling system may be configured to increase the temperature of the patient’s forehead as part of a waking routine.

[0104] Another aspect of one form of the present technology, is a patient interface configured to deliver a flow of breathable gas to a patient for treatment of a respiratory disorder, the patient interface comprising: a plenum chamber pressurisable to a therapeutic pressure of at least 4 cmH20 above ambient air pressure throughout a patient’s respiratory cycle in use, the plenum chamber comprising: a seal-forming structure constructed and arranged to form a seal with a region of the patient’s face surrounding at least one entrance to the patient’s airways, a positioning and stabilising structure configured to maintain the seal-forming structure in position on the patient’s face in use, and a vent configured to vent a gas from the plenum chamber to ambient, wherein the vent is fluidly connected to a conduit, such that the vented gas is directed through the conduit towards a forehead region of the patient in use.

[0105] In examples, the conduit may be adjustably connected to the vent to allow for control of the amount and/or direction of vented gas directed towards the patient’s forehead region. [0106] In examples, the patient interface may comprise a shell constructed of a material having a greater rigidity than the seal forming structure, and wherein the conduit is fluidly connected to the shell.

[0107] In examples, the conduit may be moulded to the shell. In other examples the conduit may be attached to the shell, such as being releasably attached.

[0108] In examples the conduit may be connected to the seal forming structure.

[0109] In examples the vent may comprise a central component and an outer housing, wherein the central component may be rotatable with respect to the outer housing to adjust the amount of flow directed towards the forehead of the patient. [0110] Another aspect of one form of the present technology, an air circuit is provided, the air circuit being configured to deliver a flow of breathable gas to a patient interface, for treatment of a respiratory disorder, the air circuit comprising: an air tube configured to receive the flow of breathable gas, the air tube comprising a first end which is configured to connect to a flow generator and a second end which is configured to connect to the patient interface; at least one vent configured to discharge at least a portion of the flow of breathable gas, and/or a gas exhaled by a patient in use to the ambient environment; and at least one conduit configured to direct the discharged gas towards the forehead of the patient in use.

[0111] In examples the first end of the air tube may comprise a connector or cuff configured to facilitate connection of the air circuit to the flow generator.

[0112] In examples the second end of the air tube may comprise a connector or cuff to facilitate connection of the air circuit to the flow generator.

[0113] In examples the second end of the air tube may comprise a decoupling structure. For example, the decoupling structure may have a patient interface side and an air tube side.

[0114] In examples, the conduit may be connected to the patient interface side of the decoupling structure.

[0115] In examples, the air circuit may comprise one or more heating elements configured to heat air in the air tube.

[0116] In examples the heating element may be a heated wire circuit, and may comprise one or more transducers, such as temperature sensors. [0117] In examples, the heated wire circuit may be helically wound around a longitudinal axis of the air circuit.

[0118] According to another aspect of one form of the present technology, a vent is provided for a respiratory pressure therapy system, the respiratory pressure therapy system being configured to deliver a flow of pressurised breathable gas to the airways of a patient in use, wherein the vent is configured to pass at least a portion of the pressurised breathable gas out of the respiratory pressure therapy system, and wherein the vent is fluidly coupled to a conduit, such that the portion of the pressurised breathable gas passed through the vent is directed towards the forehead of the patient. [0119] In examples, the vent may be configured to pass the at least a portion of the pressurised breathable gas out of a plenum chamber of the patient interface to an ambient environment.

[0120] In examples, the vent may be configured to pass at least a portion of a gas exhaled by the patient out of a plenum chamber and to an ambient environment.

[0121] In examples the vent may be adjustable to control the amount of pressurised breathable gas which is directed towards the forehead of the patient. [0122] In examples, the vent may comprise a central component and an outer housing, wherein the central component may be rotatable with respect to the outer housing to adjust the amount of flow directed towards the forehead of the patient. [0123] In examples, the conduit may be attached to the vent.

[0124] According to another aspect of one form of the present technology, a forehead cooling system is provided, which comprises a positioning and stabilising structure configured to hold a forehead cooler in contact with the forehead of a user. [0125] In examples the forehead cooler may be a thermoelectric cooler.

[0126] In examples the forehead cooler may be a fluid cooler.

[0127] In examples, the forehead cooling system may further comprise a pump to circulate a fluid through the forehead cooler. For example, the fluid may be a liquid or gas.

[0128] In examples the forehead cooler may be configured to direct a flow of air onto the forehead of the user.

[0129] In examples the forehead cooling system may comprise one or more sensors configured to measure the moisture, temperature, heart rate or provide electroencephalogram (EEG) information about the user. [0130] In examples the forehead cooling system may be configured to actively cool the forehead of the user to a pre-configured temperature.

[0131] In examples the forehead cooling system may be configured to detect when the user falls asleep.

[0132] In examples the forehead cooling system may be configured to reduce the forehead cooling when sleep is detected.

[0133] In examples the forehead cooling system may be configured to alert the user when it is time to wake. For example the forehead cooling system may increase the temperature of the forehead of the user when it is time to wake.

[0134] According to another aspect of one form of the present technology, a method of controlling a forehead cooling system is provided, the method comprising the steps of:

A) obtaining patient information from one or more sensors;

B) comparing the obtained information against one or more pre-defined rules

C) if the rule conditions are met, performing an action.

[0135] In examples the method may further comprise the step of determining whether the patient is awake or asleep.

[0136] In examples the pre-defined rules may include whether the patient is awake, and whether the forehead temperature is above a predefined threshold, within a predefined range, or below a predefined threshold. In other examples the predefined rules may include whether the patient is asleep and whether the forehead cooling system should be deactivated, activated in a low-power state, or configured to target a predefined sleep temperature range.

[0137] In examples the action performed comprises one or more of: controlling the temperature of the forehead of the patient, generating auditory stimulus, changing a rate of fluid flow within the cooling system, activating or deactivating the cooling system.

[0138] Another form of the present technology comprises a patient interface configured to deliver a flow of breathable gas to a patient for treatment of a respiratory disorder, the patient interface comprising: a plenum chamber pressurisable to a therapeutic pressure of at least 4 cmH20 above ambient air pressure throughout a patient’s respiratory cycle in use, the plenum chamber comprising: a seal-forming structure constructed and arranged to form a seal with a region of the patient’s face surrounding at least one entrance to the patient’s airways, a positioning and stabilising structure configured to maintain the seal-forming structure in position on the patient’s face in use, and a forehead cooling system, configured to cool the forehead of the patient in use, and a processor configured to detect a sleep state of the patient, wherein the forehead cooling system is controlled in accordance with the detected sleep state of the patient.

[0139] Another aspect of one form of the present technology is a patient interface that is moulded or otherwise constructed with a perimeter shape which is complementary to that of an intended wearer.

[0140] An aspect of one form of the present technology is a method of manufacturing apparatus.

[0141] Another aspect of one form of the present technology is a method of assembling a modular system comprising selecting a positioning and stabilising structure, and connecting the positioning and stabilising structure to either a first cushion or a second cushion.

[0142] An aspect of certain forms of the present technology is a medical device that is easy to use, e.g. by a person who does not have medical training, by a person who has limited dexterity, vision or by a person with limited experience in using this type of medical device.

[0143] An aspect of one form of the present technology is a portable RPT device that may be carried by a person, e.g., around the home of the person.

[0144] An aspect of one form of the present technology is a patient interface that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment. An aspect of one form of the present technology is a humidifier tank that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment.

[0145] The methods, systems, devices and apparatus described may be implemented so as to improve the functionality of a processor, such as a processor of a specific purpose computer, respiratory monitor and/or a respiratory therapy apparatus. Moreover, the described methods, systems, devices and apparatus can provide improvements in the technological field of automated management, monitoring and/or treatment of respiratory conditions, including, for example, sleep disordered breathing.

[0146] Of course, portions of the aspects may form sub-aspects of the present technology. Also, various ones of the sub-aspects and/or aspects may be combined in various manners and also constitute additional aspects or sub-aspects of the present technology.

[0147] Other features of the technology will be apparent from consideration of the information contained in the following detailed description, abstract, drawings and claims.

4 BRIEF DESCRIPTION OF THE DRAWINGS

[0148] The present technology is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numerals refer to similar elements including:

4.1 RESPIRATORY THERAPY SYSTEMS

[0149] Fig. 1A shows a system including a patient 1000 wearing a patient interface 3000, in the form of nasal pillows, receiving a supply of air at positive pressure from an RPT device 4000. Air from the RPT device 4000 is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000. A bed partner 1100 is also shown. The patient is sleeping in a supine sleeping position.

[0150] Fig. IB shows a system including a patient 1000 wearing a patient interface 3000, in the form of a nasal mask, receiving a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000.

[0151] Fig. 1C shows a system including a patient 1000 wearing a patient interface 3000, in the form of a full-face mask, receiving a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000. The patient is sleeping in a side sleeping position.

4.2 RESPIRATORY SYSTEM AND FACIAL ANATOMY

[0152] Fig. 2A shows an overview of a human respiratory system including the nasal and oral cavities, the larynx, vocal folds, oesophagus, trachea, bronchus, lung, alveolar sacs, heart and diaphragm.

[0153] Fig. 2B shows a view of a human upper airway including the nasal cavity, nasal bone, lateral nasal cartilage, greater alar cartilage, nostril, lip superior, lip inferior, larynx, hard palate, soft palate, oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea. [0154] Fig. 2C is a front view of a face with several features of surface anatomy identified including the lip superior, upper vermilion, lower vermilion, lip inferior, mouth width, endocanthion, a nasal ala, nasolabial sulcus and cheilion. Also indicated are the directions superior, inferior, radially inward and radially outward.

[0155] Fig. 2D is a side view of a head with several features of surface anatomy identified including glabella, sellion, pronasale, subnasale, lip superior, lip inferior, supramenton, nasal ridge, alar crest point, otobasion superior and otobasion inferior. Also indicated are the directions superior & inferior, and anterior & posterior.

[0156] Fig. 2E is a further side view of a head. The approximate locations of the Frankfort horizontal and nasolabial angle are indicated. The coronal plane is also indicated.

4.3 PATIENT INTERFACE

[0157] Fig. 3 A shows a patient interface in the form of a nasal mask in accordance with one form of the present technology.

[0158] Fig. 3A-1 shows forces acting on the patient interface of Fig. 3A, while in use.

[0159] Fig. 3Z shows a patient interface having conduit headgear, in accordance with one form of the present technology.

[0160] Fig. 3Z-1 shows forces acting on the patient interface of Fig. 3Z, while in use.

4.4 RPT DEVICE

[0161] Fig. 4A shows an RPT device in accordance with one form of the present technology.

[0162] Fig. 4B is a schematic diagram of the pneumatic path of an RPT device in accordance with one form of the present technology. The directions of upstream and downstream are indicated with reference to the blower and the patient interface. The blower is defined to be upstream of the patient interface and the patient interface is defined to be downstream of the blower, regardless of the actual flow direction at any particular moment. Items which are located within the pneumatic path between the blower and the patient interface are downstream of the blower and upstream of the patient interface.

4.5 HUMIDIFIER

[0163] Fig. 5A shows an isometric view of a humidifier in accordance with one form of the present technology. [0164] Fig. 5B shows an isometric view of a humidifier in accordance with one form of the present technology, showing a humidifier reservoir 5110 removed from the humidifier reservoir dock 5130.

4.6 BREATHING WAVEFORMS

[0165] Fig. 6A shows a model typical breath waveform of a person while sleeping.

4.7 MODULARITY

[0166] Fig. 7A shows a perspective view of a cushion of a patient interface configured to be worn by a patient and convey pressurized air to the patient’s nose and the patient’s mouth.

[0167] Fig. 7B shows a perspective view of a cushion of a patient interface configured to be worn by a patient and convey pressurized air to the patient’s nose.

[0168] Fig. 7C shows a perspective view of tubes usable with either the cushion of Fig. 7A or the cushion of Fig. 7B.

[0169] Fig. 7D shows a perspective view of rigidiser arms usable with either the cushion of Fig. 7A of the cushion of Fig. 7B.

[0170] Fig. 7E shows a perspective view of headgear straps usable with the cushion of Fig. 7A.

[0171] Fig. 7F shows a perspective view of headgear straps usable with the cushion of Fig. 7B.

[0172] Fig. 7G shows a front view of a pair of sleeves that is removably fitted to either the tubes of Fig. 7C or the rigidiser arms of Fig. 7D.

[0173] Fig. 7H shows a front view of a full sleeve that is removably fitted to the rigidiser arms of Fig. 7D.

[0174] Fig. 71 shows a front perspective view of yet another alternate form of a full sleeve that is removably fitted to the rigidiser arms of Fig. 7D.

[0175] Fig. 7J is a front view of a patient wearing a patient interface with a nose and mouth cushion in a tube up configuration.

[0176] Fig. 7K is a front view of a patient wearing a patient interface with a nose and mouth cushion in a tube down configuration.

[0177] Fig. 7L is a front view of a patient wearing a patient interface with a nasal cushion in a tube up configuration.

[0178] Fig. 7M is a front view of a patient wearing a patient interface with a nasal cushion in a tube down configuration. [0179] Fig. 7N is an isolated perspective view of the vent of Fig. 7L.

[0180] Fig. 70 is an isolated perspective view of a portion of the air circuit of

Fig. 7M.

4.8 FOREHEAD COOLING

[0181] Fig. 8 A shows an example of a patient interface 3000 and positioning and stabilising structure 3300 comprising a forehead cooling system 2000.

[0182] Fig. 8B shows a perspective view of an air circuit according to one example of the technology.

[0183] Fig. 8C shows a perspective view of an air circuit according to another example of the technology.

[0184] Fig. 9 shows a schematic diagram of a fluid-based forehead cooling system.

[0185] Fig. 10 shows an example of a respiratory therapy system comprising a forehead cooling system.

[0186] Fig. 11 shows an example of an active cooling system in the form of a thermoelectric cooler, and interface for extracting heat from a fluid.

[0187] Fig. 12A shows a block diagram of an air-assisted thermoelectric cooling system.

[0188] Fig. 12B shows an example of a combined PAP therapy system whereby the vented air is directed towards a forehead cooling system.

[0189] Fig. 13 shows a cooling control state machine in accordance with one example of the technology.

[0190] Fig. 14 shows a simultaneous heating and cooling system configured to heat or humidify a supply of breathable gas to be breathed by a patient, and to cool the forehead of the patient.

[0191] Fig. 15A shows an example of an air circuit configured to direct a flow of air to the forehead of the patient.

[0192] Fig. 15B shows a further example of an air circuit configured to direct a flow of air to the forehead of the patient.

[0193] Fig. 15C shows an example of a patient interface in use, wherein the air circuit is configured to direct a flow or air to the forehead of the patient.

[0194] Fig. 16A shows an example of a cushion module/patient interface comprising a conduit configured to direct a flow of air to the forehead of the patient. [0195] Fig. 16B shows an example of a cushion module/patient interface comprising an adjustable conduit configured to direct a flow of air to the forehead of the patient.

[0196] Fig. 16C shows a rear view of a cushion module/patient interface in accordance with Fig. 16 A.

[0197] Fig. 17A shows a front view of a patient interface in use with a forehead cooling system according to one example of the technology.

[0198] Fig. 17B shows a front view of a patient interface in use with a forehead cooling system according to another example of the technology.

[0199] Fig. 17C shows a front view of a patient interface in use with a forehead cooling system according to another example of the technology.

[0200] Fig. 18A shows a front view of a patient interface in use with a vent configured to direct a flow of air towards the forehead of the patient.

[0201] Fig. 18B shows a perspective view of the vent of Fig. 18A.

[0202] Fig. 18C shows a perspective view of the central component of the vent of

Fig. 18 A.

[0203] Fig. 19A shows a side view of a patient interface according to another example of the technology.

[0204] Fig. 19B shows a side view of another patient interface according to another example of the technology.

[0205] Fig 20A shows a perspective view of a patient interface according to one example of the technology.

[0206] Fig. 20B shows a perspective view of a forehead cooling system in accordance with another example of the technology.

[0207] Fig. 20C shows a top down view of a forehead cooling system in accordance with another example of the technology.

[0208] Fig. 21 A shows a side view of a VR device comprising a patient interface.

[0209] Fig. 2 IB shows a cross-sectional view of the VR device of Fig. 21 A taken through the sagittal plane of the patient.

[0210] Fig. 22A is a diagram of an example system for monitoring sleep and providing insights and/or recommendations, which includes a computing device. [0211] Fig. 22B is a diagram of the components of an example computing device in accordance with Fig. 22A. [0212] Fig. 23 is a flow diagram showing a control method for automated sleep on-set detection and cooling control.

[0213] Fig. 24 is an example of a user interface for receiving feedback on sleep performance and/or controlling the operation of one or more forehead cooling systems.

5 DETAILED DESCRIPTION OF EXAMPLES OF THE

TECHNOLOGY

[0214] Before the present technology is described in further detail, it is to be understood that the technology is not limited to the particular examples described herein, which may vary. It is also to be understood that the terminology used in this disclosure is for the purpose of describing only the particular examples discussed herein, and is not intended to be limiting.

[0215] The following description is provided in relation to various examples which may share one or more common characteristics and/or features. It is to be understood that one or more features of any one example may be combinable with one or more features of another example or other examples. In addition, any single feature or combination of features in any of the examples may constitute a further example.

5.1 THERAPY

[0216] In one form, the present technology comprises a method for treating a respiratory disorder comprising applying positive pressure to the entrance of the airways of a patient 1000.

[0217] In certain examples of the present technology, a supply of air at positive pressure is provided to the nasal passages of the patient via one or both nares.

[0218] In certain examples of the present technology, mouth breathing is limited, restricted or prevented.

5.2 RESPIRATORY THERAPY SYSTEMS

[0219] In one form, the present technology comprises a respiratory therapy system for treating a respiratory disorder. The respiratory therapy system may comprise an RPT device 4000 for supplying a flow of air to the patient 1000 via an air circuit 4170 and a patient interface 3000 or 3800. 5.3 PATIENT INTERFACE

[0220] A non-invasive patient interface 3000, such as that shown in Fig. 3A, in accordance with one aspect of the present technology comprises the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilising structure 3300, a vent 3400, one form of connection port 3600 for connection to air circuit 4170, and a forehead support 3700. In some forms a functional aspect may be provided by one or more physical components. In some forms, one physical component may provide one or more functional aspects. In use the seal-forming structure 3100 is arranged to surround an entrance to the airways of the patient so as to maintain positive pressure at the entrance(s) to the airways of the patient 1000. The sealed patient interface 3000 is therefore suitable for delivery of positive pressure therapy.

[0221] As shown in Fig. 3Z, a non-invasive patient interface 3000 in accordance with another aspect of the present technology comprises the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilising structure 3300, a vent 3400 and one form of connection port 3600 for connection to an air circuit (such as the air circuit 4170 shown in Figs. 1A-1C). The plenum chamber 3200 may be formed of one or more modular components (e.g., a cushion module 3150 together with the seal-forming structure 3100) in the sense that it or they can be replaced with different components, for example components of a different size.

[0222] If a patient interface is unable to comfortably deliver a minimum level of positive pressure to the airways, the patient interface may be unsuitable for respiratory pressure therapy.

[0223] The patient interface 3000 in accordance with one form of the present technology is constructed and arranged to be able to provide a supply of air at a positive pressure above the ambient, for example at least 2, 4, 6, 10, or 20 cmH20 with respect to ambient.

5.3.1 Seal-forming structure

[0224] In one form of the present technology, a seal-forming structure 3100 provides a target seal-forming region, and may additionally provide a cushioning function. The target seal-forming region is a region on the seal-forming structure 3100 where sealing may occur. The region where sealing actually occurs- the actual sealing surface- may change within a given treatment session, from day to day, and from patient to patient, depending on a range of factors including for example, where the patient interface was placed on the face, tension in the positioning and stabilising structure and the shape of a patient’s face.

[0225] In one form the target seal-forming region is located on an outside surface of the seal-forming structure 3100.

[0226] In certain forms of the present technology, the seal-forming structure 3100 is constructed from a biocompatible material, e.g. silicone rubber.

[0227] A seal-forming structure 3100 in accordance with the present technology may be constructed from a soft, flexible, resilient material such as silicone.

[0228] In certain forms of the present technology, a system is provided comprising more than one a seal-forming structure 3100, each being configured to correspond to a different size and/or shape range. For example the system may comprise one form of a seal-forming structure 3100 suitable for a large sized head, but not a small sized head and another suitable for a small sized head, but not a large sized head.

5.3.1.1 Sealing mechanisms

[0229] In one form, the seal-forming structure includes a sealing flange utilizing a pressure assisted sealing mechanism. In use, the sealing flange can readily respond to a system positive pressure in the interior of the plenum chamber 3200 acting on its underside to urge it into tight sealing engagement with the face. The pressure assisted mechanism may act in conjunction with elastic tension in the positioning and stabilising structure.

[0230] In one form, the seal-forming structure 3100 comprises a sealing flange and a support flange. The sealing flange comprises a relatively thin member with a thickness of less than about 1mm, for example about 0.25mm to about 0.45mm, which extends around the perimeter of the plenum chamber 3200. Support flange may be relatively thicker than the sealing flange. The support flange is disposed between the sealing flange and the marginal edge of the plenum chamber 3200, and extends at least part of the way around the perimeter. The support flange is or includes a springlike element and functions to support the sealing flange from buckling in use.

[0231] In one form, the seal-forming structure may comprise a compression sealing portion or a gasket sealing portion. In use the compression sealing portion, or the gasket sealing portion is constructed and arranged to be in compression, e.g. as a result of elastic tension in the positioning and stabilising structure.

[0232] In one form, the seal-forming structure comprises a tension portion. In use, the tension portion is held in tension, e.g. by adjacent regions of the sealing flange.

[0233] In one form, the seal-forming structure comprises a region having a tacky or adhesive surface.

[0234] In certain forms of the present technology, a seal-forming structure may comprise one or more of a pressure-assisted sealing flange, a compression sealing portion, a gasket sealing portion, a tension portion, and a portion having a tacky or adhesive surface.

5.3.1.2 Nose bridge or nose ridge region

[0235] In one form, the non-invasive patient interface 3000 comprises a sealforming structure that forms a seal in use on a nose bridge region or on a nose-ridge region of the patient's face.

[0236] In one form, the seal-forming structure includes a saddle-shaped region constructed to form a seal in use on a nose bridge region or on a nose-ridge region of the patient's face.

5.3.1.3 Upper lip region

[0237] In one form, the non-invasive patient interface 3000 comprises a sealforming structure that forms a seal in use on an upper lip region (that is, the lip superior) of the patient's face.

[0238] In one form, the seal-forming structure includes a saddle-shaped region constructed to form a seal in use on an upper lip region of the patient's face.

5.3.1.4 Chin-region

[0239] In one form the non-invasive patient interface 3000 comprises a sealforming structure that forms a seal in use on a chin-region of the patient's face.

[0240] In one form, the seal-forming structure includes a saddle-shaped region constructed to form a seal in use on a chin-region of the patient's face.

5.3.1.5 Forehead region

[0241] In one form, the seal-forming structure that forms a seal in use on a forehead region of the patient's face. In such a form, the plenum chamber may cover the eyes in use. 5.3.1.6 Nasal pillows

[0242] In one form the seal-forming structure of the non-invasive patient interface 3000 comprises a pair of nasal puffs, or nasal pillows, each nasal puff or nasal pillow being constructed and arranged to form a seal with a respective naris of the nose of a patient.

[0243] Nasal pillows in accordance with an aspect of the present technology include: a frusto-cone, at least a portion of which forms a seal on an underside of the patient's nose, a stalk, a flexible region on the underside of the frusto-cone and connecting the frusto-cone to the stalk. In addition, the structure to which the nasal pillow of the present technology is connected includes a flexible region adjacent the base of the stalk. The flexible regions can act in concert to facilitate a universal joint structure that is accommodating of relative movement both displacement and angular of the frusto-cone and the structure to which the nasal pillow is connected. For example, the frusto-cone may be axially displaced towards the structure to which the stalk is connected.

5.3.1.7 Nose-only Masks

[0244] In one form, the patient interface 3000 comprises a seal-forming structure 3100 configured to seal around an entrance to the patient’s nasal airways but not around the patient’s mouth. The seal-forming structure 3100 may be configured to seal to the patient’s lip superior. The patient interface 3000 may leave the patient’s mouth uncovered. This patient interface 3000 may deliver a supply of air or breathable gas to both nares of patient 1000 and not to the mouth. This type of patient interface may be identified as a nose-only mask.

[0245] One form of nose-only mask according to the present technology is what has traditionally been identified as a “nasal mask”, having a seal-forming structure 3100 configured to seal on the patient’s face around the nose and over the bridge of the nose. A nasal mask may be generally triangular in shape. In one form, the non- invasive patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use to an upper lip region (e.g. the lip superior), to the patient’s nose bridge or at least a portion of the nose ridge above the pronasale, and to the patient's face on each lateral side of the patient’s nose, for example proximate the patient’s nasolabial sulci. The patient interface 3000 shown in Fig. IB has this type of seal-forming structure 3100. This patient interface 3000 may deliver a supply of air or breathable gas to both nares of patient 1000 through a single orifice. [0246] Another form of nose-only mask may seal around an inferior periphery of the patient’s nose without engaging the patient’s nasal ridge. This type of patient interface 3000 may be identified as a “nasal cradle” mask and the seal-forming structure 3100 may be identified as a “nasal cradle cushion”, for example. In one form, for example as shown in Fig. 3Z, the seal-forming structure 3100 is configured to form a seal in use with inferior surfaces of the nose around the nares. The sealforming structure 3100 may be configured to seal around the patient’s nares at an inferior periphery of the patient’s nose including to an inferior and/or anterior surface of a pronasale region of the patient’s nose and to the patient’s nasal alae. The sealforming structure 3100 may seal to the patient’s lip superior. The shape of the sealforming structure 3100 may be configured to match or closely follow the underside of the patient’s nose and may not contact a nasal bridge region of the patient’s nose or any portion of the patient’s nose superior to the pronasale. In one form of nasal cradle cushion, the seal-forming structure 3100 comprises a bridge portion dividing the opening into two orifices, each of which, in use, supplies air or breathable gas to a respective one of the patient’s nares. The bridge portion may be configured to contact or seal against the patient’s columella in use. Alternatively, the seal-forming structure 3100 may comprise a single opening to provide a flow or air or breathable gas to both of the patient’s nares.

[0247] In some forms, a nose-only mask may comprise nasal pillows, described above.

5.3.1.8 Nose and Mouth Masks

[0248] In one form, the patient interface 3000 comprises a seal-forming structure 3100 configured to seal around an entrance to the patient’s nasal airways and also around the patient’s mouth. The seal -forming structure 3100 may be configured to seal to the patient’s face proximate a chin region. This patient interface 3000 may deliver a supply of air or breathable gas to both nares and to the mouth of patient 1000. This type of patient interface may be identified as a nose and mouth mask. [0249] One form of nose-and-mouth mask according to the present technology is what has traditionally been identified as a “full-face mask”, having a seal-forming structure 3100 configured to seal on the patient’s face around the nose, below the mouth and over the bridge of the nose. A nose-and-mouth mask may be generally triangular in shape. In one form the patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use to a patient’s chin-region (which may include the patient’s lip inferior and/or a region directly inferior to the lip inferior), to the patient’s nose bridge or at least a portion of the nose ridge superior to the pronasale, and to cheek regions of the patient's face. The patient interface 3000 shown in Fig. 1C is of this type. This patient interface 3000 may deliver a supply of air or breathable gas to both nares and mouth of patient 1000 through a single orifice. This type of sealforming structure 3100 may be referred to as a “nose-and-mouth cushion”.

[0250] In another form the patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use on a patient’s chin region (which may include the patient’s lip inferior and/or a region directly inferior to the lip inferior), to an inferior and/or an anterior surface of a pronasale portion of the patient’s nose, to the alae of the patient’s nose and to the patient’s face on each lateral side of the patient’s nose, for example proximate the nasolabial sulci. The seal-forming structure 3100 may also form a seal against a patient’s lip superior. A patient interface 3000 having this type of seal-forming structure may have a single opening configured to deliver a flow of air or breathable gas to both nares and mouth of a patient, may have an oral hole configured to provide air or breathable gas to the mouth and a nasal hole configured to provide air or breathable gas to the nares, or may have an oral hole for delivering air to the patient’s mouth and two nasal holes for delivering air to respective nares. This type of patient interface 3000 may have a nasal portion and an oral portion, the nasal portion sealing to the patient’s face at similar locations to a nasal cradle mask.

[0251] In a further form of nose and mouth mask, the patient interface 3000 may comprise a seal-forming structure 3100 having a nasal portion comprising nasal pillows and an oral portion configured to form a seal to the patient’s face around the patient’s mouth.

[0252] In some forms, the seal-forming structure 3100 may have a nasal portion that is separate and distinct from an oral portion. In other forms, a seal-forming structure 3100 may form a contiguous seal around the patient’s nose and mouth.

[0253] It is to be understood that the above examples of different forms of patient interface 3000 do not constitute an exhaustive list of possible configurations. In some forms a patient interface 3000 may comprise a combination of different features of the above described examples of nose-only and nose and mouth masks. 5.3.2 Plenum chamber

[0254] The plenum chamber 3200 has a perimeter that is shaped to be complementary to the surface contour of the face of an average person in the region where a seal will form in use. In use, a marginal edge of the plenum chamber 3200 is positioned in close proximity to an adjacent surface of the face. Actual contact with the face is provided by the seal-forming structure 3100. The seal-forming structure 3100 may extend in use about the entire perimeter of the plenum chamber 3200. In some forms, the plenum chamber 3200 and the seal-forming structure 3100 are formed from a single homogeneous piece of material.

[0255] In certain forms of the present technology, the plenum chamber 3200 does not cover the eyes of the patient in use. In other words, the eyes are outside the pressurised volume defined by the plenum chamber. Such forms tend to be less obtrusive and / or more comfortable for the wearer, which can improve compliance with therapy.

[0256] In certain forms of the present technology, the plenum chamber 3200 is constructed from a transparent material, e.g. a transparent polycarbonate. The use of a transparent material can reduce the obtrusiveness of the patient interface, and help improve compliance with therapy. The use of a transparent material can aid a clinician to observe how the patient interface is located and functioning.

[0257] In certain forms of the present technology, the plenum chamber 3200 is constructed from a translucent material. The use of a translucent material can reduce the obtrusiveness of the patient interface, and help improve compliance with therapy. [0258] In some forms, the plenum chamber 3200 is constructed from a rigid material such as polycarbonate. The rigid material may provide support to the sealforming structure.

[0259] In some forms, the plenum chamber 3200 is constructed from a flexible material (e.g., constructed from a soft, flexible, resilient material like silicone, textile, foam, etc.). For example, in examples then may be formed from a material which has a Young's modulus of 0.4 GPa or lower, for example foam. In some forms of the technology the plenum chamber 3200 may be made from a material having Young's modulus of 0.1 GPa or lower, for example rubber. In other forms of the technology the plenum chamber 3200 may be made from a material having a Young's modulus of 0.7MPa or less, for example between 0.7MPa and 0.3MPa. An example of such a material is silicone.

5.3.2.1.1 Nose and Mouth Mask

[0260] As shown in Fig. 7A, the plenum chamber 3200-1 includes a pair of plenum chamber inlet ports 3254-1, which may be used to convey gas into and/or out of the plenum chamber 3200-1. The plenum chamber inlet ports 3254-1 may be disposed on opposite sides (e.g., left and right sides) of the plenum chamber 3200-1. [0261] In some forms, the plenum chamber 3200-1 may also include at least one vent opening 3402-1 (see e.g., Fig. 7A). The vent opening 3402-1 may be disposed in a center of the plenum chamber 3200-1. For example, the vent opening 3402-1 may be disposed between the plenum chamber inlet ports 3254-1.

[0262] In some forms, the plenum chamber 3200-1 may include a pair of grooves 3266-1. Each groove 3266-1 may be disposed proximate to one of the plenum chamber inlet ports 3254-1. Each groove 3266-1 may form a partially recessed surface.

5.3.2.1.2 Nose-only Mask

[0263] The plenum chamber 3200-2 of a nasal only cushion 3050-2 may be similar to the plenum chamber 3200-1 of the mouth and nose cushion 3050-1. Only some similarities and differences between the plenum chambers 3200-1, 3200-2 may be described below.

[0264] As shown in Fig. 7B, the plenum chamber 3200-2 includes a pair of plenum chamber inlet ports 3254-2, which may be used to convey gas into and/or out of the plenum chamber 3200-2. The plenum chamber inlet ports 3254-2 may be disposed on opposite sides (e.g., left and right sides) of the plenum chamber 3200-2. [0265] In some forms, the plenum chamber 3200-2 may also include at least one vent opening 3402-2 (see e.g., Fig. 7B). The vent opening 3402-2 may be disposed in a center of the plenum chamber 3200-2. For example, the vent opening 3402-2 may be disposed between the plenum chamber inlet ports 3254-2.

[0266] In some forms, the plenum chamber 3200-2 may include a pair of grooves 3266-2. Each groove 3266-2 may be disposed proximate to one of the plenum chamber inlet ports 3254-2. Each groove 3266-2 may form a partially recessed surface. 5.3.3 Positioning and stabilising structure

[0267] The seal-forming structure 3100 of the patient interface 3000 of the present technology may be held in sealing position in use by the positioning and stabilising structure 3300. The positioning and stabilising structure 3300 may comprise and function as “headgear” since it engages the patient’s head in order to hold the patient interface 3000 in a sealing position. Examples of a positioning and stabilising structure may be shown in Figs. 3 A and 3A-1.

[0268] In one form the positioning and stabilising structure 3300 provides a retention force at least sufficient to overcome the effect of the positive pressure in the plenum chamber 3200 to lift off the face (i.e., Fplenum).

[0269] In one form the positioning and stabilising structure 3300 provides a retention force to overcome the effect of the gravitational force on the patient interface 3000.

[0270] With continued reference to Fig. 3A-1, the positioning and stabilising structure 3300 provides a force FPSS that assists in maintaining the plenum chamber 3200 in the sealing position on the patient’s face. The positioning and stabilising force FPSS may be the resultant force from the various forces of the different elements of the positioning and stabilising structure 3300. For example, headgear straps may individually provide a strap force Fstrap in order to hold the seal-forming structure 3100 against the patient’ s face. The force Fstrap may also be directed at least partially in the superior direction in order to overcome the gravitational force Fg. The gravitational force Fg may be specifically shown for the seal-forming structure 3100 and the plenum chamber 3200, but gravity would act on the entirely of the patient interface 3000 (i.e., in the same direction as the illustrated gravitational force Fg).

[0271] The gravitational force Fg may be opposed by a frictional force Ff, which may act in a direction directly opposite of the gravitational force Fg. As gravity pulls the seal-forming structure 3100 and the plenum chamber 3200 in the inferior direction (as viewed in Fig. 3A-1), the frictional force Ff would act in the superior direction (e.g., against a patient’s face). For example, the patient may experience the frictional force Ff against his lip superior (and/or other surfaces of the patient’s face in contact with the seal-forming structure 3100) in order to oppose the motion in the inferior direction (which may help to stabilising the cushion in place). Although the frictional force Ff is shown specifically opposing the gravitational force Fg of the seal-forming structure 3100 and the plenum chamber 3200, components of an overall frictional force (not shown) would also oppose the gravitational force Fg associated with the positioning and stabilising structure 3300 and any other portions of the patient interface 3000. A force of friction can act along any place where the patient interface 3000 contacts the patient’s skin (or hair). The frictional force Ff extends in the opposite direction of the gravitational force Fg and along the patient’s skin (or hair). In some forms the gravitiational force Fg may also be countered by vertical components of the reaction force from the patient’s face acting on the seal-forming structure 3100, for example at the nose ridge and chin regions of the patient’s face, for example.

[0272] In some forms, the sum of the various forces may equal zero so that the patient interface 3000 is at equilibrium (e.g., not moving along the patient’s face while in use). Specifically, the gravitational force Fg and the blowout force Fplenum tend to move the seal-forming structure 3100 away from the desired sealing position. The positioning and stabilising force FPSS is applied in order to counteract the gravitational force Fg and the blowout force Fplenum (as well as any frictional forces Ff) and keep the seal-forming structure 3100 properly situated. Although the positioning and stabilising force FPSS may exceed the sum of the gravitational force Fg and the blowout force Fplenum (with any additional positioning and stabilising force FPSS being balanced by reaction force from the patient’s head acting on the portions of patient interface 3000) and still maintain the seal-forming structure 3100 in an appropriate sealing position, patient comfort may be sacrificed. Maximum patient comfort may be achieved when the net force on the patient interface 3000 is zero and the positioning and stabilising force FPSS is exactly strong enough to achieve this. In some examples the positioning and stabilising structure 3300 may be adjustable such that when fitted the positioning and stabilising force FPSS is greater than required to exactly balance the gravitational force Fg and the blowout force Fplenum to hold the patient interface 3000 against the patient’s head tightly enough that disruptive forces which may be experienced in use (such as tube drag or lateral shunting of the plenum chamber 3200 during side sleeping) do not disrupt the seal. As described below, various positions of the patient’s head while using the patient interface 3000 may determine the positioning and stabilising force FPSS necessary to achieve equilibrium. [0273] In one form the positioning and stabilising structure 3300 provides a retention force as a safety margin to overcome the potential effect of disrupting forces on the patient interface 3000, such as from tube drag, or accidental interference with the patient interface.

[0274] In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured in a manner consistent with being worn by a patient while sleeping. In one example the positioning and stabilising structure 3300 has a low profile, or cross-sectional thickness, to reduce the perceived or actual bulk of the apparatus. In one example, the positioning and stabilising structure 3300 comprises at least one strap having a rectangular cross-section. In one example the positioning and stabilising structure 3300 comprises at least one flat strap.

[0275] In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured so as not to be too large and bulky to prevent the patient from lying in a supine sleeping position with a back region of the patient’s head on a pillow.

[0276] In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured so as not to be too large and bulky to prevent the patient from lying in a side sleeping position with a side region of the patient’s head on a pillow.

[0277] In one form of the present technology, a positioning and stabilising structure 3300 is provided with a decoupling portion located between an anterior portion of the positioning and stabilising structure 3300, and a posterior portion of the positioning and stabilising structure 3300. The decoupling portion does not resist compression and may be, e.g. a flexible or floppy strap. The decoupling portion is constructed and arranged so that when the patient lies with their head on a pillow, the presence of the decoupling portion prevents a force on the posterior portion from being transmitted along the positioning and stabilising structure 3300 and disrupting the seal.

[0278] In one form of the present technology, a positioning and stabilising structure 3300 comprises a strap constructed from a laminate of a fabric patientcontacting layer, a foam inner layer and a fabric outer layer. In one form, the foam is porous to allow moisture, (e.g., sweat), to pass through the strap. In one form, the fabric outer layer comprises loop material to engage with a hook material portion. [0279] In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap that is extensible, e.g. resiliently extensible. For example the strap may be configured in use to be in tension, and to direct a force to draw a seal-forming structure into sealing contact with a portion of a patient’s face. In an example the strap may be configured as a tie.

[0280] In one form of the present technology, the positioning and stabilising structure comprises a first tie, the first tie being constructed and arranged so that in use at least a portion of an inferior edge thereof passes superior to an otobasion superior of the patient’s head and overlays a portion of a parietal bone without overlaying the occipital bone.

[0281] In one form of the present technology suitable for a nasal-only mask or for a full-face mask, the positioning and stabilising structure includes a second tie, the second tie being constructed and arranged so that in use at least a portion of a superior edge thereof passes inferior to an otobasion inferior of the patient’s head and overlays or lies inferior to the occipital bone of the patient’s head.

[0282] In one form of the present technology suitable for a nasal-only mask or for a full-face mask, the positioning and stabilising structure includes a third tie that is constructed and arranged to interconnect the first tie and the second tie to reduce a tendency of the first tie and the second tie to move apart from one another.

[0283] In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap that is bendable and e.g. non-rigid. An advantage of this aspect is that the strap is more comfortable for a patient to lie upon while the patient is sleeping.

[0284] In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap constructed to be breathable to allow moisture vapour to be transmitted through the strap,

[0285] In certain forms of the present technology, a system is provided comprising more than one positioning and stabilising structure 3300, each being configured to provide a retaining force to correspond to a different size and/or shape range. For example the system may comprise one form of positioning and stabilising structure 3300 suitable for a large sized head, but not a small sized head, and another, suitable for a small sized head, but not a large sized head. 5.3.3.1 Conduit headgear

5.3.3.1.1 Conduit headgear tubes

[0286] In some forms of the present technology, the positioning and stabilising structure 3300 comprises one or more headgear tubes 3350 that deliver pressurised air received from a conduit forming part of the air circuit 4170 from the RPT device to the patient’s airways, for example through the plenum chamber 3200 and sealforming structure 3100. In the form of the present technology illustrated in Fig. 3Z, the positioning and stabilising structure 3300 comprises two tubes 3350 that deliver air to the plenum chamber 3200 from the air circuit 4170. The tubes 3350 are configured to position and stabilise the seal-forming structure 3100 of the patient interface 3000 at the appropriate part of the patient’s face (for example, the nose and/or mouth) in use. This allows the conduit of air circuit 4170 providing the flow of pressurised air to connect to a connection port 3600 of the patient interface in a position other than in front of the patient’s face, for example on top of the patient’s head.

[0287] In the form of the present technology illustrated in Fig. 3Z, the positioning and stabilising structure 3300 comprises two tubes 3350, each tube 3350 being positioned in use on a different side of the patient’s head and extending across the respective cheek region, above the respective ear (superior to the otobasion superior on the patient’s head) to the elbow 3610 on top of the head of the patient 1000. This form of technology may be advantageous because, if a patient sleeps with their head on its side and one of the tubes 3350 is compressed to block or partially block the flow of gas along the tube 3350, the other tube 3350 remains open to supply pressurised gas to the patient. In other examples of the technology, the patient interface 3000 may comprise a different number of tubes, for example one tube, or two or more tubes.

[0288] In one example in which the patient interface has one tube 3350, the single tube 3350 is positioned on one side of the patient’s head in use (e.g. across one cheek region) and a strap forms part of the positioning and stabilising structure 3300 and is positioned on the other side of the patient’s head in use (e.g. across the other region) to assist in securing the patient interface 3000 on the patient’s head. For example, the tube 3350 and the strap may each be under tension in use in order to assist in maintaining the seal-forming structure 3100 in a sealing position. [0289] In one form, the tube 3350 may be at least partially extensible so that the tube 3350 and the strap may adjust substantially equal lengths when worn by a patient. This may allow for substantially symmetrical adjustments between the tube 3350 and the strap so that the seal-forming structure remains substantially in the middle.

[0290] In the form of the technology shown in Fig. 3Z, the two tubes 3350 are fluidly connected at superior ends to each other and to the connection port 3600. In some examples, the two tubes 3350 are integrally formed while in other examples the tubes 3350 are formed separately but are connected in use and may be disconnected, for example for cleaning or storage. Where separate tubes are used, they may be indirectly connected together, for example each may be connected to a T-shaped connector. The T-shaped connector may have two arms/branches each fluidly connectable to a respective one of the tubes 3350. Additionally, the T-shaped connector may have a third arm or opening providing the connection port 3600 for fluid connection to the air circuit 4170 in use. The opening may be an inlet 3332 (see e.g., 7C) for receiving the flow of pressurized air.

[0291] In some forms, the third arm of the T-shaped connector may be substantially perpendicular to each of the first two arms.

[0292] In some forms, the third arm of the T-shaped connector may be obliquely formed with respect to each of the first two arms.

[0293] In some forms, a Y-shaped connector may be used instead of the T-shaped connector. The first two arms may be oblique with respect to one another, and the third arm may be oblique with respect to the first two arms. The angled formation of the first two arms may be similar to the shape of the patient’s head in order to conform to the shape.

[0294] In some forms, at least one of the arms of the T-shaped connector (or Y- shaped connector) may be flexible. This may allow the connector to bend based on the shape of the patient’s head and/or a force in the positioning and stabilising structure 3300.

[0295] In some forms, at least one of the arms of the T-shaped connector (or Y- shaped connector) may be at least partially rigidised. This may assist in maintaining the shape of the connector so that bending of the connector does not close the airflow path. [0296] The tubes 3350 may be formed from a flexible material, such as an elastomer, e.g. silicone or TPE, and/or from one or more textile and/or foam materials. The tubes 3350 may have a preformed shape and may be able to be bent or moved into another shape upon application of a force but may return to the original preformed shape in the absence of said force. The tubes 3350 may be generally arcuate or curved in a shape approximating the contours of a patient’s head between the top of the head and the nasal or oral region.

[0297] In some examples, the one or more tubes 3350 are crush resistant to resist being blocked if crushed during use, for example if squashed between a patient’s head and pillow, especially if there is only one tube 3350. The tubes 3350 may be formed with a sufficient structural stiffness to resist crushing or may be as described in US Patent No. 6,044,844, the contents of which are incorporated herein by reference. [0298] Each tube 3350 may be configured to receive a flow of air from the connection port 3600 on top of the patient’s head and to deliver the flow of air to the seal-forming structure 3100 at the entrance of the patient’s airways. In the example shown in Fig. 3Z, each tube 3350 lies in use on a path extending from the plenum chamber 3200 across the patient’s cheek region and superior to the patient’s ear to the elbow 3610. For example, a portion of each tube 3350 proximate the plenum chamber 3200 may overlie a maxilla region of the patient’s head in use. Another portion of each tube 3350 may overlie a region of the patient’s head superior to an otobasion superior of the patient’s head. Each of the tubes 3350 may also lie over the patient’s sphenoid bone and/or temporal bone and either or both of the patient’s frontal bone and parietal bone. The elbow 3610 may be located in use over the patient’s parietal bone, over the frontal bone and/or over the junction therebetween (e.g. the coronal suture).

[0299] In certain forms of the present technology the patient interface 3000 is configured such that the connection port 3600 can be positioned in a range of positions across the top of the patient’s head so that the patient interface 3000 can be positioned as appropriate for the comfort or fit of an individual patient. In some examples, the headgear tubes 3350 are configured to allow movement of an upper portion of the patient interface 3000 (e.g. a connection port 3600) with respect to a lower portion of the patient interface 3000 (e.g. a plenum chamber 3200). That is, the connection port 3600 may be at least partially decoupled from the plenum chamber 3200. In this way, the seal-forming structure 3100 may form an effective seal with the patient’s face irrespective of the position of the connection port 3600 (at least within a predetermined range of positions) on the patient’s head.

[0300] As described above, in some examples of the present technology the patient interface 3000 comprises a seal-forming structure 3100 in the form of a cradle cushion which lies generally under the nose and seals to an inferior periphery of the nose (e.g. an under-the-nose cushion). The positioning and stabilising structure 3300, including the tubes 3350 may be structured and arranged to pull the seal-forming structure 3100 into the patient’s face under the nose with a sealing force in a posterior and superior direction (e.g. a posterosuperior direction). A sealing force with a postero superior direction may cause the seal-forming structure 3100 to form a good seal to both the inferior periphery of the patient’s nose and anterior-facing surfaces of the patient’s face, for example on either side of the patient’s nose and the patient’s lip superior.

[0301] Conduits forming part of the positioning and stabilising structure 3300, like headgear straps, may provide a force that contributes to the positioning and stabilising force FPSS. As illustrated in Fig. 3Z-1, the positioning and stabilising force FPSS may be the resultant force from the various forces of the different elements of the positioning and stabilising structure 3300. For example, each conduit may provide a force Fconduit directed in the posterior and respective lateral direction in order to hold the seal-forming structure 3100 against the patient’s face (into the upper lip and sealing under the nose) and oppose the effect of the positive pressure in the plenum chamber 3200 to lift off the face (i.e., Fplenum). The force Fconduit directed may also be directed at least partially in the superior direction in order to overcome the gravitational force Fg.

[0302] In some forms, the conduits may provide a force directed into the patient’s head when the conduits are filled with pressurized air. The force may assist in gripping the patient’s head. The force may be caused by the inflation of the conduits during normal use. In some forms, the force may provide a cushioning effect to the patient’s head. The conduits may be designed in order to limit expansion in order to prevent over-gripping the patient’s head.

[0303] The position of the patient’s head may also change the gripping force of the conduits. For example, if the patient is sleeping on his side, the weight of the patient’s head may compress one conduit, and the other conduit (e.g., the lateral portion not between the patient’s head and a sleeping surface, like a pillow) may additionally expand in order to keep substantially the same flow rate of pressurized air.

[0304] The gravitational force Fg may be opposed by a frictional force Ff, which may act in a direction directly opposite of the gravitational force Fg. As gravity pulls the seal-forming structure 3100 and the plenum chamber 3200 in the inferior direction (as viewed in Fig. 3A-1), the frictional force Ff would act in the superior direction (e.g., against a patient’s face). For example, the patient may experience the frictional force Ff against his lip superior (and/or other surfaces of the patient’s face in contact with the seal-forming structure 3100) in order to oppose the motion in the inferior direction (which may help to stabilising the cushion in place). Although the frictional force Ff is shown specifically opposing the gravitational force Fg of the seal-forming structure 3100 and the plenum chamber 3200, components of an overall frictional force (not shown) would also oppose the gravitational force Fg associated with the positioning and stabilising structure 3300 and any other portions of the patient interface 3000. A force of friction can act along any place where the patient interface 3000 contacts the patient’s skin (or hair). The frictional force Ff extends in the opposite direction of the gravitational force Fg and along the patient’s skin (or hair). [0305] In some forms, the sum of the various forces may equal zero so that the patient interface 3000 is at equilibrium (e.g., not moving along the patient’s face while in use). Specifically, the gravitational force Fg and the blowout force Fplenum tend to move the seal-forming structure 3100 away from the desired sealing position. The positioning and stabilising force FPSS is applied in order to counteract the gravitational force Fg and the blowout force Fplenum (as well as any frictional forces Ff) and keep the seal-forming structure 3100 properly situated. Although the positioning and stabilising force FPSS may exceed the sum of the gravitational force Fg and the blowout force Fplenum (with any additional positioning and stabilising force FPSS being balanced by reaction force from the patient’s head acting on the portions of patient interface 3000) and still maintain the seal-forming structure 3100 in an appropriate sealing position, patient comfort may be sacrificed. Maximum patient comfort may be achieved when the net force on the patient interface 3000 is zero and the positioning and stabilising force FPSS is exactly strong enough to achieve this. In some examples the positioning and stabilising structure 3300 may be adjustable such that when fitted the positioning and stabilising force FPSS is greater than required to exactly balance the gravitational force Fg and the blowout force Fplenum to hold the patient interface 3000 against the patient’s head tightly enough that disruptive forces which may be experienced in use (such as tube drag or lateral shunting of the plenum chamber 3200 during side sleeping) do not disrupt the seal. As described below, various positions of the patient’s head while using the patient interface 3000 may determine the positioning and stabilising force FPSS necessary to achieve equilibrium

5.3.3.1.2 Extendable and non-extendable tube portions

[0306] In some examples of the present technology, one or both of the tubes 3350 are not extendable in length. However, in some forms, the tubes 3350 may comprise one or more extendable tube sections, for example formed by an extendable concertina structure. In some forms, the patient interface 3000 may comprise a positioning and stabilising structure 3300 including at least one gas delivery tube comprising a tube wall having an extendable concertina structure. The patient interface 3000 shown in Fig. 3Z comprises tubes 3350, the superior portions of which comprise extendable tube sections each in the form of an extendable concertina structure 3362.

[0307] In some forms, the extendable concertina structure 3328 may be formed as a series of ridges and grooves on the surface of the tubes 3350. The concertina structure 3328 may be biased toward a retracted position, and may move to an expanded position when the patient dons the positioning and stabilising structure 3300. Because portions of the tubes 3350 may be substantially inextensible (e.g., non- extendable tube sections 3363), the concertina structures 3328 permit the positioning and stabilising structure 3300 to stretch in order to fit different sized heads. This may allow a single sized tube 3350 to be used with multiple sized heads. For example, the positioning and stabilising structure 3300 may be “one-size-fits-all” as a result of the concertina structure 3328. Alternatively, the tubes 3350 may be manufactured in multiple sizes (e.g., small, medium, large). The patient may select a length that most closely conforms to their head, and the concertina structures 3328 may make small adjustments in order to tailor the fit to the individual patient.

[0308] In some forms, the inlet 3332 may be disposed in the middle of the conduit 6320. For example, the tubes 3350 may be symmetric about the inlet 3332 through at least one axis.

[0309] The cross-sectional shape of the non-extendable tube sections 3363 of the tubes 3350 may be circular, elliptical, oval, D-shaped or a rounded rectangle, for example as described in US Patent No. 6,044,844. A cross-sectional shape that presents a flattened surface of tube on the side that faces and contacts the patient’s face or other part of the head may be more comfortable to wear than, for example a tube with a circular cross-section.

[0310] In some examples of the present technology, the non-extendable tube sections 3363 connects to the plenum chamber 3200 from a low angle. The headgear tubes 3350 may extend inferiorly down the sides of the patient’s head and then curve anteriorly and medially to connect to the plenum chamber 3200 in front of the patient’s face. The tubes 3350, before connecting to the plenum chamber 3200, may extend to a location at the same vertical position as (or, in some examples, inferior to) the connection with the plenum chamber 3200. That is, the tubes 3350 may project in an at least partially superior direction before connecting with the plenum chamber 3200. A portion of the tubes 3350 may be located inferior to the plenum chamber 3200 and/or the seal forming structure 3100. The tubes 3350 may contact the patient’s face below the patient’s cheekbones, which may be more comfortable than contact on the patient’s cheekbones and may avoid excessively obscuring the patient’s peripheral vision.

5.3.3.1.3 Conduit headgear connection port

[0311] In certain forms of the present technology, the patient interface 3000 may comprise a connection port 3600 located proximal to a superior, lateral or posterior portion of a patient’s head. For example, in the form of the present technology illustrated in Fig 3Z, the connection port 3600 is located on top of the patient’s head (e.g. at a superior location with respect to the patient’s head). In this example the patient interface 3000 comprises an elbow 3610 forming the connection port 3600. The elbow 3610 may be configured to fluidly connect with a conduit of an air circuit 4170. The elbow 3610 may be configured to swivel with respect to the positioning and stabilising structure 3300 to at least partially decouple the conduit from the positioning and stabilising structure 3300. In some examples the elbow 3610 may be configured to swivel by rotation about a substantially vertical axis and, in some particular examples, by rotation about two or more axes. In some examples the elbow may comprise or be connected to the tubes 3350 by a ball-and-socket joint. The connection portion 3600 may be located in the sagittal plane of the patient’s head in use. [0312] Patient interfaces having a connection port that is not positioned anterior to the patient’s face may be advantageous as some patients may find a conduit that connects to a patient interface anterior to their face to be unsightly and/or obtrusive. For example, a conduit connecting to a patient interface anterior to the patient’s face may be prone to interference with bedclothes or bed linen, particularly if the conduit extends inferiorly from the patient interface in use. Forms of the present technology comprising a patient interface having a connection port positioned superiorly to the patient’s head in use may make it easier or more comfortable for a patient to lie or sleep in one or more of the following positions: a side-sleeping position, a supine position (e.g. on their back, facing generally upwards) or in a prone position (e.g. on their front, facing generally downwards). Moreover, connecting a conduit to an anterior portion of a patient interface may exacerbate a problem known as tube drag in which the conduit exerts an undesired force upon the patient interface during movement of the patient’s head or the conduit, thereby causing dislodgement away from the face. Tube drag may be less of a problem when force is received at a superior location of the patient’s head than anterior to the patient’s face proximate to the seal-forming structure (where tube drag forces may be more likely to disrupt the seal).

5.3.3.1.4 Headgear Tube Fluid Connections

[0313] The two tubes 3350 are fluidly connected at their inferior ends to the plenum chamber 3200. In certain forms of the technology, the connection between the tubes 3350 and the plenum chamber 3200 is achieved by connection of two rigid connectors. The tubes 3350 and plenum chamber 3200 may be configured to enable the patient to easily connect the two components together in a reliable manner. The tubes 3350 and plenum chamber 3200 may be configured to provide tactile and/or audible feedback in the form of a ‘re-assuring click’ or a similar sound, so that the patient may easily know that each tube 3350 has been correctly connected to the plenum chamber 3200. In one form, the tubes 3350 are formed from a silicone or textile material and the inferior end of each of the silicone tubes 3350 is overmolded to a rigid connector made, for example, from polypropylene, polycarbonate, nylon or the like. The rigid connector on each tube 3350 may comprise a female mating feature configured to connect with a male mating feature on the plenum chamber 3200. Alternatively, the rigid connector on each tube 3350 may comprise a male mating feature configured to connect to a female mating feature on the plenum chamber 3200. In other examples the tubes 3350 may each comprise a male or female connector formed from a flexible material, such as silicone or TPE, for example the same material from which the tubes 3350 are formed.

[0314] In other examples a compression seal is used to connect each tube 3350 to the plenum chamber 3200. For example, a resiliently flexible (e.g. silicone) tube 3350 without a rigid connector may be configured to be squeezed to reduce its diameter so that it can be compressed into a port in the plenum chamber 3200 and the inherent resilience of the silicone pushes the tube 3350 outwards to seal the tube 3350 in the port in an air-tight manner. Alternatively, in a hard-to-hard type engagement between the tube 3350 and the plenum chamber 3200, each tube 3350 and/or plenum chamber 3200 may comprise a pressure activated seal, for example a peripheral sealing flange. When pressurised gas is supplied through the tubes 3350 the sealing flange may be urged against the join between the tubes and a circumferential surface around a port or connector of the plenum chamber 3200 to form or enhance a seal between the tube 3350 and plenum chamber 3200.

5.3.3.2 Headgear straps

[0315] In some forms, the positioning and stabilising structure 3300 may include headgear 3302 with at least one strap which may be worn by the patient in order to assist in properly orienting the seal-forming structure 3100 against the patient’s face (e.g., in order to limit or prevent leaks).

[0316] As described above, some forms of the headgear 3302 may be constructed from a textile material, which may be comfortable against the patient’s skin. The textile may be flexible in order to conform to a variety of facial contours. Although the textile may include rigidisers along a selected length, which may limit bending, flexing, and/or stretching of the headgear 3302.

[0317] In certain forms, the headgear 3302 may be at least partially extensible. For example, the headgear 3302 may include elastic, or a similar extensible material. For example, the entire headgear 3302 may be extensible or selected portions may be extensible (or more extensible than surrounding portions). This may allow the headgear 3302 to stretch while under tension, which may assist in providing a sealing force for the seal-forming structure 3100.

[0318] Two forms of the headgear, four-point headgear 3302-1 and two-point headgear 3302-2, are discussed in more detail below as illustrative examples. 5.3.3.2.1 Four-point connection

[0319] As shown in Fig. 7E, some forms of the headgear 3302-1 may be a four- point connection headgear. This means that the headgear 3302-1 may connect to four separate places on the plenum chamber 3200, on a frame connected to the plenum chamber 3200, and/or on arms connected to the plenum chamber 3200. The headgear 3302-1 may include four different straps providing a tensile force to help maintain the seal-forming structure 3100 in a sealing position. The positioning and stabilising structure 3300 of Fig. 3A may also be considered a four-point connection headgear. [0320] In some forms, the headgear 3302-1 may include inferior straps 3304-1, which may connect to an inferior portion of the cushion 3050-1. The inferior straps

3304-1 may extend along the patient’s cheek toward a posterior region of the patient’s head. For example, the inferior straps 3304-1 may overlay the masseter muscle on either side of the patient’s face. The inferior straps 3304-1 may therefore contact the patient’s head below the patient’s ears. The inferior straps 3304-1 may meet at the posterior of the patient’s head, and may overlay the occipital bone and/or the trapezius muscle.

[0321] The headgear 3302-1 may also include superior straps 3305-1, which may overlay the temporal bones, parietal bone, and/or occipital bone. The superior straps

3305-1 may also connect to the tubes 3350 (e.g., by interfacing with the tabs 3320). [0322] A rear strap 3307-1 may extend between the superior straps 3305-1 and between the inferior straps 3304-1. The inferior and superior straps 3304-1, 3305-1 on a given side (e.g., left or right) may also be connected to the rear strap 3307-1 adjacent to one another. The height of the rear strap 3307-1 may therefore be approximately the combined height of the inferior and superior strap 3304-1, 3305-1. The rear strap 3307-1 may overlay the occipital bone and/or the pariental bone in use. This may allow the rear strap 3307-1 to assist in anchoring the headgear 3302-1 to the patient’s head.

[0323] In the illustrated example, the headgear 3302-1 may be formed with a substantially X-shape. The inferior and superior straps 3304-1, 3305-1 may be connected to a rear strap 3307-1 using stitching, ultrasonic welding, or any similar process.

[0324] In some forms, the inferior straps 3304-1 are connected to a magnetic member 3306-1. For example, each inferior straps 3304-1 may be threaded through a magnetic member 3306-1, so that a length of each inferior strap 3304-1 may be adjusted. The magnetic members 3306-1 may removably connect to the magnets 3370-1 (described below), so that the inferior straps 3304-1 may be disconnected from the plenum chamber 3200, but the length of the inferior straps 3304-1 may not be affected.

[0325] In some forms, the superior straps 3305-1 may be connected directly to the tabs 3320 of the tubes 3350. The superior straps 3305-1 may be threaded through the tabs 3320 in order to adjust the length and control the tensile force of each superior strap 3305-1.

[0326] In some forms, the headgear 3302-1 may be used only with the nose and mouth cushion 3050-1 (e.g., because the nose-only cushion 3050-1 does not have four connection points). However, the headgear 3302-1 may be used interchangeably with the tubes 3350 and the rigidiser arms 3340.

5.3.3.2.2 Two-point connection

[0327] As shown in Fig. 7F, some forms of the headgear 3302-2 may be a two- point connection headgear. This means that the headgear 3302-2 may connect to two separate places.

[0328] In some forms, the headgear 3302-2 may be formed from a continuous piece of material. In other words, the headgear 3302-2 may not be formed from multiple straps connected (e.g., stitched) together. This may be comfortable for a patient as they will not be in contact with any seams or joints connecting different straps. In other forms, the headgear 3302-2 may be formed from multiple straps (e.g., two superior straps, a rear strap, etc.) that are connected together (e.g., with stitching, ultra-sonic welding, etc.).

[0329] In certain forms of the present technology, the positioning and stabilising structure 3300 comprises at least one headgear strap acting in addition to the tubes 3350 to position and stabilise the seal-forming structure 3100 at the entrance to the patient’s airways. As shown in Fig. 3Z, the patient interface 3000 comprises a strap 3307-2 forming part of the positioning and stabilising structure 3300. The strap 3307- 2 may be known as a back strap or a rear headgear strap, for example. The rear strap 3307-2 may overlay the temporal bones, parietal bone, and/or occipital bone. In other examples of the present technology, one or more further straps may be provided. For example, patient interfaces 3000 according to examples of the present technology having a nose-and-mouth cushion may have a second, lower, strap configured to lie against the patient’s head proximate the patient’s neck and/or against posterior surfaces of the patient’s neck.

[0330] In the example shown in Fig. 3Z, strap 3310 of the positioning and stabilising structure 3300 is connected between the two tubes 3350 positioned on each side of the patient’s head and passing around the back of the patient’s head, for example overlying or lying inferior to the occipital bone of the patient’s head in use. The strap 3310 connects to each tube above the patient’s ears. With reference to Fig. 3Z, the positioning and stabilising structure 3300 comprises a pair of tabs 3320. In use a strap 3310 may be connected between the tabs 3320. The strap 3310 may be sufficiently flexible to pass around the back of the patient’s head and lie comfortably against the patient’s head, even when under tension in use.

[0331] As shown in Fig. 7F, some forms of the headgear 3302-2 may be at least partially bifurcated. For example, a rear strap 3307-2 of the headgear 3302-2 (e.g., configured to contact the posterior portion of the patient’s head) may be wider than the surrounding portions of the headgear 3302-2. An intermediate section 3308-2 of the rear strap 3307-2 may include a slit 3309-2. A superior section of the rear strap 3307-2 may therefore be movable relative to the inferior section as a result of the slit 3309-2. This may allow the patient to have a larger strap coverage on the posterior region of their head, which may assist in better anchoring the headgear 3302-2 to the patient’s head since there is no inferior strap (e.g., 3304-1).

[0332] In some forms, the headgear 3302-2 may be used only with the nasal cushion 3050-2 (e.g., because the nose and mouth cushion 3050-1 does not have four connection points). However, the headgear 3302-2 may be used interchangeably with the tubes 3350 and the rigidiser arms 3340.

5.3.3.3 Rigidiser Arm

[0333] As shown in Fig. 7D, a rigidiser arm 3340 may be an elongated, rigid member that assists in maintaining the cushion (e.g., the nose and mouth cushion 3050-1 or the nasal cushion 3050-2) in an operating position. The rigidiser arm 3340 may contact a side of the patient’s head and provide a force to limit slipping of the seal-forming structure 3100 from the patient’s nose and/or mouth.

[0334] In some forms, the rigidiser arm 3340 is constructed from a rigid material (e.g., plastic). The rigid material may not permit the rigidiser arm 3340 to stretch. Additionally, the rigidiser arm 3340 may be substantially inflexible and may be unable to bend. The rigidiser arm 3340 may be pre-molded into a desired shape in order to fit a patient’s head. For example, the rigidiser arms 3340 may be molded with a curved shape to substantially correspond to the shape of the side of the patient’s head (e.g., overlaying the masseter muscle and/or the temporal bone).

[0335] In certain forms, the rigidiser arm 3340 may be molded in order to conform to a specific patient’s head (e.g., the rigidiser arm 3340 is customized). [0336] In some forms, the rigidiser arm 3340 may be flexible along at least one direction. For example, the rigidiser arm 3340 may be flexible about its width and may be inflexible along its length. In other words, the rigidiser arm 3340 may be bendable about an axis along the width of the rigidiser arm 3340, but may be unable to bend about an axis perpendicular to the rigidiser arm 3340. This may allow an individual patient to adjust the rigidiser arm 3340 in order to better fit their individual head.

[0337] In certain forms, the rigidiser arm 3340 may remain in the new position after being bent. This may allow a patient adjust the shape of the rigidiser arm 3340 for their specific head and then the rigidiser arm 3340 will keep the desired shape while in use in order to promote patient comfort.

[0338] In some forms, a first end 3342 of the rigidiser arm 3340 may be a free end and a second end 3344 (e.g., opposite of the first end 3342) of the rigidiser arm 3340 may be fixed. The first end 3342 may be curved in order to minimize sharp edges that could cause patient discomfort. The first end 3342 may also overlay the patient’s head proximate to the temporal bone, in use. The second end 3344 may be fixed to an arm connection structure 3504.

[0339] In some forms, the arm connection structure 3504 may be similar to the conduit connection structure 3500. For example, the arm connection structure 3504 and the conduit connection structure 3500 may have substantially the same shape. This may allow either the conduit connection structure 3500 or the arm connection structure 3504 to fit into the groove (e.g., 3266-1 or 3266-2) and connect to the plenum chamber inlet port 3254. The arm connection structure 3504 may connect to the nose and mouth cushion 3050-1 or the nose-only cushion 3050-2 in substantially the same way as the conduit connection structure 3500 (e.g., via a snap fit, press fit, friction fit, etc.).

[0340] In some forms, the arm connection structure 3504 may act as a plug for the plenum chamber inlet port 3254 (e.g., either 3254-1 and/or 3254-2). Unlike the tubes 3350, the rigidiser arm 3340 does not convey pressurized air to the plenum chamber 3200. The rigidised arm 3340 may be used with a “tube down” configuration, where a hose is connected to the vent opening 3402 (e.g., either 3402-1 and/or 3402-2), and conveys air into the plenum chamber 3200 through the vent opening 3402. In this example, air does not need to travel into or out of the plenum chamber inlet openings 3254. Thus, the arm connection structure 3504 may form a seal with the plenum chamber inlet opening 3254 in order to limit airflow into or out of the plenum chamber 3200.

5.3.4 Vent

[0341] In one form, the patient interface 3000 includes a vent 3400 constructed and arranged to allow for the washout of exhaled gases, e.g. carbon dioxide.

[0342] In certain forms the vent 3400 is configured to allow a continuous vent flow from an interior of the plenum chamber 3200 to ambient whilst the pressure within the plenum chamber is positive with respect to ambient. The vent 3400 is configured such that the vent flow rate has a magnitude sufficient to reduce rebreathing of exhaled CO2 by the patient while maintaining the therapeutic pressure in the plenum chamber in use.

[0343] One form of vent 3400 in accordance with the present technology comprises a plurality of holes, for example, about 20 to about 80 holes, or about 40 to about 60 holes, or about 45 to about 55 holes.

[0344] The vent 3400 may be located in the plenum chamber 3200. Alternatively, the vent 3400 is located in a decoupling structure, e.g., a swivel.

[0345] As shown in Fig. 7N, a vent 3450 may be used with the patient interface 3000. The vent 3450 may have a substantially similar shape to the vent opening 3402-

1 (e.g., a substantially circular shape).

[0346] The vent 3450 may be used with either the mouth and nose plenum chamber 3200-1 (e.g., illustrated in Figs. 7A) or the nose-only plenum chamber 3200-

2 (e.g., illustrated in Figs. 7B).

[0347] With continued reference to Fig. 7A, the vent 3450 may include a vent housing 3404, which may be configured to engage with the vent opening 3402. The vent housing 3404 may be constructed from a rigid material or a semi-rigid material. For example, the vent housing 3404 may be constructed from plastic, metal, or any similar material. The vent housing 3404 may add rigidity to the patient interface 3000 (e.g., to limit unwanted bending that may affect the position of the seal-forming structure 3100 on the patient’s face).

[0348] The vent housing 3404 may include an anterior surface 3408, a posterior surface 3412, and a sidewall/groove 3416. The anterior surface 3408 faces away from the patient’s face in use, and may be positioned outside the pressurized volume of the plenum chamber 3200. The posterior surface 3412 is disposed opposite to the anterior surface 3408. In use, the posterior surface 3412 may face the patient and may be disposed within the pressurized volume of the plenum chamber 3200. The groove or sidewall 3416 may be formed between the anterior and posterior surfaces 3408, 3412. A portion of the plenum chamber 3200 may be received within the groove/sidewall 3416 in order to retain the vent 3400 in position.

[0349] In some forms, a diffuser 3448 may be used with the vent housing 3404. The diffuser 3448 may assist with limiting the decibel output from any of the patient interface 3000 (or any other patient interface). Specifically, the diffuser 3448 may assist in limiting the decibel level associated with air output from the patient interface 3000 (e.g., exhaled air), although the diffuser 3448 may limit the decibel level of at any point in the patient interface.

[0350] In certain forms, the diffuser 3448 may diffuse, and therefore slow, the exhaust gas exiting the plenum chamber 3200 and passing through the vent housing 3404. The diffuser 3448 may assist in avoiding jetting and associated discomfort to the patient and/or bed partner (e.g., noise caused by jetting against a pillow, sheets, bedclothes, etc.).

[0351] In some forms, the diffuser may include an central component 3456 that has an outer surface which faces away from the patient in use. An outer diameter of the central component 3456 may be less than an inner diameter of the vent housing 3404 proximate to the anterior surface 3408. This may form a gap 3464 through which air may travel.

5.3.5 Decoupling structure(s)

[0352] In one form the patient interface 3000 includes at least one decoupling structure, to for at least one portion of the patient interface to move with respect to another portion of the patient interface. For example the decoupling structure may be configured to decouple the connection port from the seal-forming structure. In some examples the decoupling structure may be, a swivel or a ball and socket. 5.3.6 Connection port

[0353] Connection port 3600 allows for connection to the air circuit 4170.

5.3.7 Forehead support

[0354] In one form, the patient interface 3000 includes a forehead support 3700.

5.3.8 Anti-asphyxia valve

[0355] In one form, the patient interface 3000 includes an anti-asphyxia valve.

5.3.9 Ports

[0356] In one form of the present technology, a patient interface 3000 includes one or more ports that allow access to the volume within the plenum chamber 3200. In one form this allows a clinician to supply supplementary oxygen. In one form, this allows for the direct measurement of a property of gases within the plenum chamber 3200, such as the pressure.

5.3.10 Modularity

[0357] As described above, the cushion, headgear, and sleeves may come in different styles, which may correspond to different uses (e.g., mouth breathing, nasal breathing, etc.). A patient or clinician may select certain combinations of cushions, headgear, and sleeves in order to optimize the effectiveness of the therapy and/or the individual patient’s comfort. An example of this sort of modular design is described in PCT/SG2022/050777 filed 28 October 2022, incorporated herein by reference in its entirety.

[0358] In some forms, the different styles of cushions, headgear, and sleeves may be used interchangeably with one another in order to form different combinations of patient interfaces. This may be beneficial from a manufacturing prospective because wider variety of patient interfaces may be created using fewer parts. Additionally or alternatively, the various combinations may allow a patient to change styles of patient interface without changing the every component. This modular design is described in more detail below and in Singapore Patent Application No. 10202112048R, the entire contents of which is incorporated by reference herein in its entirety.

[0359] Air may be delivered to the patient in one of two main ways. In one example, the patient may receive the flow of pressurized air through headgear tubes 3350 (see e.g., Fig. 3Z). This may be referred to as a “tube up” configuration and may position a connection port at the top of the patient’s head. In other example, the patient may receive the flow of pressurized air through a conduit connected to the plenum chamber 3200, for example through the connection port 3600 (see e.g., Fig. 3A). This may be referred to a “tube down” configuration where the airflow conduit is positioned in front of the patient’s face. Different patients may be more comfortable with one style of air delivery over the other (e.g., because of the patient’s sleep style). Therefore, it may be beneficial to allow a single style of patient interface to be used in either the “tube up” or “tube down” configuration.

[0360] The patient interface may be part of a modular assembly with a variety of interchangeable components that may be swapped out by a patient and/or clinician for one or more components for a different style. The following description describes the various combinations that may be created by assembling the different components together.

5.3.10.1 Sleeve

[0361] In some forms, to allow for modularity, a sleeve may be used with the tubes 3350 and/or the rigidisier arms 3340. The sleeve may at least partially surround the tubes 3350 and/or the rigidiser arms 3340. As shown in Figs. 7G to 71, different shapes of sleeves may be used, which may correspond to different types of positioning and stabilising structures 3300. In some forms, the configuration of the sleeve may be customized to fit a particular patient’s face. For instance, the sleeves may be configured in a relatively more posterior region of the patient’s head.

[0362] In some forms, the sleeve may be constructed from a comfortable material. For example, the sleeve may be constructed from a textile material, a foam material, or a combination of the two. The comfortable material may contact the patient in use, and may feel soft against the patient’s skin in order to improve patient compliance.

[0363] The material may also be flexible in order to assist in donning or doffing the sleeve from the tube 3350 or the rigidiser arms 3340. For example, the material may allow the sleeve to bend in order to conform to the shape of the tubes or conduit headgear 3350 or the rigidiser arms 3340, which may change depending on the shape of an individual patient’s head.

[0364] In some forms, the sleeve may also be at least partially elastic (e.g., the material may allow the sleeve to stretch). The elastic material may help the sleeve stretch in order to fit around the tubes 3350 or the rigidiser arms 3340. The elastic material may then return to an initial position that is snug against the tubes 3350 or the rigidiser arms 3340 in order to limit the sleeve from sliding while in use. [0365] As described in more detail below, some forms of the sleeves may be specific to a rigidising element (e.g., tubes 3350 and/or rigidiser arms 3340).

However, the sleeves may assist the rigidising elements in connecting interchangeably with the version or styles of cushions (e.g., the mouth and nose cushion 3050-1, the nose-only cushion 3050-2, etc.).

5.3.10.1.1 Conduit Sleeve

[0366] As shown in Fig. 7G, one example of a sleeve is a conduit sleeve 3351, which may be usable with the tubes 3350 described above.

[0367] As shown in Fig. 7G, the conduit sleeve 3351 may include a curved shape that may be similar to the shape of the tubes 3350 shown in Fig. 7C. The flexible material used to construct the conduit sleeve 3351 may allow the conduit sleeve 3351 to further curve in order to correspond to the shape of the tubes 3350 (e.g., when worn by the patient).

[0368] In some forms, the conduit sleeve 3351 may include a first or superior opening 3352. The superior opening 3352 may be disposed at one end of the conduit sleeve 3351. The superior opening 3352 may be an opening to a passage that extends along at least a portion of the conduit sleeve 3351.

[0369] As shown in Fig. 7G, some forms of the conduit sleeve 3351 may also include an inferior extension 3354. The inferior extension 3354 may be positioned on an opposite end of the conduit sleeve 3351 from the superior opening 3352. The conduit sleeve 3351 may be customized to fit a particular user’s face. For instance, the inferior extension 3354 of the conduit sleeve 3351 may be configured in a relatively more posterior region or anterior region of the patient’s head.

[0370] Some forms of the inferior extension 3354 may include a rigid or semirigid piece (e.g., within the sleeve 3351). The rigid or semi-rigid piece may be constructed from a plastic material, or a similar material. Alternatively, the inferior extension 3354 may be stiffened using a manufacturing process (e.g., stitching rigidised thread, flat knitting, using thicker material).

[0371] As shown in Fig. 7G, some forms of the inferior extension 3354 may include a connection member 3356. In the illustrated example, the connection member 3356 may be a magnet, although in other examples, the connection member 3356 may be a different type of connector (e.g., a mechanical fastener, an adhesive, hook and loop material, etc.). The connection member 3356 may also be positioned at an end of the inferior extension 3354, although the connection member 3356 could alternatively be positioned anywhere along the inferior extension 3354.

[0372] In some forms, the connection member 3356 (e.g., a magnet) may be removably connected to the magnets 3370-1 of the headgear 3302-1. For example, when the conduit sleeves 3351 are connected to the tubes 3350 (see e.g., Fig. 7J), the magnets 3370-1 connected to the inferior straps 3304-1 may be removably connected to the connection member 3356 in order to provide the tensile force.

5.3.10.1.2 Four-point arm sleeve

[0373] As shown in Fig. 7H, another example of a sleeve is a four-point arm sleeve 3380, which may be usable with the rigidiser arms 3340 described above. [0374] As shown in Fig. 7H, the four-point arm sleeve 3380 may include a curved shape that may be similar to the shape of the rigidiser arm 3340 shown in Fig. 7D. The flexible material used to construct the four-point arm sleeve 3380 may allow the four-point arm sleeve 3380 to further curve in order to correspond to the shape of the rigidiser arm 3340 (e.g., when worn by the patient and/or went bent by the patient).

[0375] As shown in Fig. 7H, some forms of the four-point arm sleeve 3380 may include an inferior extension 3384. The inferior extension 3384 may be positioned at an end of the four-point arm sleeve 3380.

[0376] In the illustrated example, the shape and/or structure of the inferior extension 3384 is substantially the same as the shape of the inferior extension 3354.

For example, the inferior extension 3384 may be more rigid as compared to the rest of the four-point arm sleeve 3380 (e.g., as a result of rigidising thread or rigid material). [0377] As shown in Fig. 7H, some forms of the inferior extension 3384 may include a connection member 3386. In the illustrated example, the connection member 3386 may be a magnet, although in other examples, the connection member 3386 may be a different type of connector (e.g., a mechanical fastener, an adhesive, hook and loop material, etc.). The connection member 3386 may also be positioned at an end of the inferior extension 3384, although the connection member 3386 could alternatively be positioned anywhere along the inferior extension 3384.

[0378] In some forms, the connection member 3386 (e.g., a magnet) may be removably connected to the magnets 3370-1 of the headgear 3302-1. For example, when the four-point arm sleeves 3380 are connected to the rigidiser arm 3340 (see e.g., Fig. 7K), the magnets 3370-1 connected to the inferior straps 3304-1 may be removably connected to the connection member 3386 in order to provide the tensile force.

[0379] As shown in Fig. 7H, the four-point arm sleeve 3380 may include a pair of tabs 3394, which may be similar to the tab 3320 on the tubes 3350. When the four- point arm sleeve 3380 is worn by the patient, the tabs 3394 may be positioned in substantially the same place on the patient’s head as where the tabs 3320 are positioned when the patient wears the tubes 3350.

5.3.10.1.3 Tvo-point arm sleeve

[0380] As shown in Fig. 71, yet another example of a sleeve is a two-point arm sleeve 3380-1, which may be usable with the rigidiser arms 3340 described above. [0381] In some forms, the two-point arm sleeve 3380-1 may be similar to the four-point arm sleeve 3380 described above. Only some similarities and differences may be described below.

[0382] As shown in Fig. 71, the two-point arm sleeve 3380-1 may include an inferior opening 3388-1 that is positioned at an end of the two-point arm sleeve 3380- 1. The inferior opening 3388-1 may form an opening to a passageway through the two-point arm sleeve 3380-1. In the illustrated example, the inferior opening 3388-1 may open into a surface of the conduit sleeve 3380-1.

[0383] As shown in Fig. 71, the two-point arm sleeve 3380-1 may include a pair of tabs 3394-1, which may be similar to the tab 3320 on the tubes 3350. When the two-point arm sleeve 3380-1 is worn by the patient, the tabs 3394-1 may be positioned in substantially the same place on the patient’s head as where the tabs 3320 are positioned when the patient wears the tubes 3350.

5.3.10.2 Assembled Patient Interfaces

[0384] As illustrated in Figs. 7J to 7M, the various elements described above may be combined into four different patient interfaces. The different patient interfaces may allow patients to use different styles based on their individual comfort. The modularity of the different elements (e.g., the ability to be used in multiple styles of patient interfaces) may simplify manufacturing and/or may allow a patient to more easily switch between styles of patient interfaces.

5.3.10.2.1 Nose and Mouth Mask Tube Up Configuration

[0385] As illustrated in Fig. 7J, the patient may wear the cushion 3050-1 in a tube-up configuration with the tubes 3350 and the four-point headgear 3302-1. This assembly may form a tube up nose and mouth patient interface 3000-1. [0386] In some forms, a conduit sleeve may be used with the tubes 3350 in order to enable a patient to experience the “tube up” air delivery style with the mouth and nose cushion 3050-1. As is described below, the conduit sleeve provides additional connection locations for connecting the four-point headgear 3302-1. However, other forms of connectors aside from or in addition to the conduit sleeve may be used.

[0387] In the illustrated example, the conduit sleeves may be connected to the tubes 3350 of the positioning and stabilising structure 3300. The tubes 3350 (via the conduit connection structure 3500), may be used to connect the tubes 3350 to the cushion 3050-1. The conduit sleeves provide the magnets in order to connect to the magnets 3370-1 (see e.g., Fig. 7E) of the four-point headgear 3302-1. Alternatively, a different connection form may be used.

[0388] As illustrated in Fig. 7J, the four-point headgear 3302-1 may connect in four separate locations in order to provide a tensile force that maintains the cushion 3050-1 in a sealing position on the patient’s head.

[0389] For example, the inferior straps 3304-1 (e.g., via the magnetic members 3306-1) may removably connect to the magnets of the conduit sleeves. In use, each inferior strap 3304-1 may contact the patient’s cheek (e.g., overlaying the masseter muscle). The inferior straps 3304-1 may also extend below the patient’s ears.

5.3.10.2.2 Nose and Mouth Mask Tube Down Configuration

[0390] As illustrated in Fig. 7K, the patient may wear the cushion 3050-1 in a tube-down configuration with the rigidiser arms 3340 and the four-point headgear 3302-1. This assembly may form a tube down nose and mouth patient interface 3000- 2.

[0391] In some forms, a conduit sleeve may be used with the rigidiser arms 3340 in order to enable a patient to experience the “tube down” air delivery style with the mouth and nose cushion 3050-1. As is described below, the conduit sleeve provides additional connection locations for connecting the four-point headgear 3302-1.

However, other forms of connectors aside from or in addition to the conduit sleeve may be used.

[0392] In the illustrated example, the conduit sleeves may be connected to the rigidiser arms 3340 of the positioning and stabilising structure 3300. The rigidiser arms 3340 (via the conduit connection structure 3504), may be used to connect the rigidiser arms 3340 to the cushion 3050-1. The conduit sleeves provide the magnets in order to connect to the magnets 3370-1 (see e.g., Fig. 7E) of the four-point headgear 3302-1. Alternatively, a different connection form may be used.

[0393] As illustrated in Fig. 7K, the four-point headgear 3302-1 may connect in four separate locations in order to provide a tensile force that maintains the cushion 3050-1 in a sealing position on the patient’s head.

[0394] For example, the inferior straps 3304-1 (e.g., via the magnetic members 3306-1) may removably connect to the magnets of the conduit sleeves. In use, each inferior strap 3304-1 may contact the patient’s cheek (e.g., overlaying the masseter muscle). The inferior straps 3304-1 may also extend below the patient’s ears.

5.3.10.2.3 Nose Mask Tube Up Configuration

[0395] As illustrated in Fig. 7L, the patient may wear the cushion 3050-2 in a tube-up configuration with the tubes 3350 and the two-point headgear 3302-2. This assembly may form a tube up nose only patient interface 3000-3

[0396] A conduit sleeve may be used with the tubes 3350, and may provide additional comfort to the patient. The sleeve may not add additional connection points to connect the positioning and stabilising structure 3300 on the cushion 3050-2. In the illustrated example, the tubes 3350 of the positioning and stabilising structure 3300 may be connected directly to the cushion 3050-2.

[0397] As illustrated in Fig. 7L, the two-point headgear 3302-2 may connect to the tabs 3320 on the tubes 3350 in order to provide a tensile force that maintains the cushion 3050-2 in a sealing position on the patient’s head.

5.3.10.2.4 Nose Mask Tube Down Configuration

[0398] As illustrated in Fig. 7M, the patient may wear the cushion 3050-2 in a tube-up configuration with the rigidiser arms 3340 and the two-point headgear 3302- 2. This assembly may form a tube down nose only patient interface 3000-4.

[0399] A conduit sleeve may be used with the rigidiser arms 3340, and may provide additional comfort to the patient. The sleeve may not add additional connection points to connect the positioning and stabilising structure 3300 on the cushion 3050-2. In the illustrated example, the rigidiser arms 3340 of the positioning and stabilising structure 3300 may be connected directly to the cushion 3050-2.

[0400] As illustrated in Fig. 7M, the two-point headgear 3302-2 may connect to the tabs 3320 on the sleeve in order to provide a tensile force that maintains the cushion 3050-2 in a sealing position on the patient’s head. 5.3.10.2.5 Modularity of Elements

[0401] Fig. 7P illustrates how the different elements can be combined in order to form the four different patient interfaces described above. As illustrated, the different components may be reused for different styles of patient interfaces. This may allow for easier manufacturing and assembly, because a large number of the same components may be produced and used in a variety of styles. The only components not used in multiple styles may be the sleeves. However, the sleeves may be easier to manufacture. Fig. 70 shows a portion of air circuit 4170 that may interface with the patient interface, while Fig. 7N shows a vent 3404 that may interchangeably replace the air circuit shown in Fig. 70, depending on the style of the patient interface.

5.4 RPT DEVICE

[0402] An RPT device 4000 in accordance with one aspect of the present technology comprises mechanical, pneumatic, and/or electrical components and is configured to execute one or more algorithms 4300, such as any of the methods, in whole or in part, described herein. The RPT device 4000 may be configured to generate a flow of air for delivery to a patient’s airways, such as to treat one or more of the respiratory conditions described elsewhere in the present document.

[0403] In one form, the RPT device 4000 is constructed and arranged to be capable of delivering a flow of air in a range of -20 L/min to +150 L/min while maintaining a positive pressure of at least 4 cmH20, or at least 10cmH2O, or at least 20 cmH20.

5.5 AIR CIRCUIT

[0404] An air circuit 4170 in accordance with an aspect of the present technology is a conduit or a tube (described herein as an air tube) constructed and arranged to allow, in use, a flow of air to travel between two components such as RPT device 4000 and the patient interface 3000 or 3800.

[0405] In particular, the air circuit 4170 may be in fluid connection with the outlet of the pneumatic block 4020 and the patient interface, for example by connecting to a connection port 3600 on the patient interface. In some examples the air circuit may include a cuff or connector to facilitate connection of the air circuit to the RPT device 4000 or flow generator, and the patient interface. For example, a first end of the conduit/air tube may comprise a connector or cuff configured to facilitate connection of the air circuit to the flow generator, and a second end of the conduit/air tube may comprise a connector or cuff to facilitate connection of the air circuit to the flow generator.

[0406] In some examples the air circuit may comprise a decoupling structure, such as a swivel or ball and socket joint to allow part of the air circuit to swivel or rotate with respect to another part of the air circuit.

[0407] The air circuit may be referred to as an air delivery tube. In some cases there may be separate limbs of the circuit for inhalation and exhalation. In other cases a single limb is used.

[0408] In some forms, the air circuit 4170 may comprise one or more heating elements configured to heat air in the air circuit, for example to maintain or raise the temperature of the air. The heating element may be in a form of a heated wire circuit, and may comprise one or more transducers, such as temperature sensors. In one form, the heated wire circuit may be helically wound around the axis of the air circuit 4170. The heating element may be in communication with a processor for control thereof. One example of an air circuit 4170 comprising a heated wire circuit is described in United States Patent 8,733,349, which is incorporated herewithin in its entirety by reference.

5.6 HUMIDIFIER

5.6.1 Humidifier overview

[0409] In one form of the present technology there is provided a humidifier 5000 (e.g. as shown in Fig. 5A) to change the absolute humidity of air or gas for delivery to a patient relative to ambient air. Typically, the humidifier 5000 is used to increase the absolute humidity and increase the temperature of the flow of air (relative to ambient air) before delivery to the patient’s airways.

[0410] The humidifier 5000 may comprise a humidifier reservoir 5110, a humidifier inlet 5002 to receive a flow of air, and a humidifier outlet 5004 to deliver a humidified flow of air. In some forms, as shown in Fig. 5A and Fig. 5B, an inlet and an outlet of the humidifier reservoir 5110 may be the humidifier inlet 5002 and the humidifier outlet 5004 respectively. The humidifier 5000 may further comprise a humidifier base 5006, which may be adapted to receive the humidifier reservoir 5110 and comprise a heating element 5240. 5.7 BREATHING WAVEFORMS

[0411] Fig. 6A shows a model typical breath waveform of a person while sleeping. The horizontal axis is time, and the vertical axis is respiratory flow rate. While the parameter values may vary, a typical breath may have the following approximate values: tidal volume Vt 0.5L, inhalation time Ti 1.6s, peak inspiratory flow rate Qpeak 0.4 L/s, exhalation time Te 2.4s, peak expiratory flow rate Qpeak - 0.5 L/s. The total duration of the breath, Ttot, is about 4s. The person typically breathes at a rate of about 15 breaths per minute (BPM), with Ventilation Vent about 7.5 L/min. A typical duty cycle, the ratio of Ti to Ttot, is about 40%.

5.8 FOREHEAD COOLING

[0412] Patients with OSA are much more likely than average to have comorbid insomnia. Forehead cooling has been shown to reduce time to sleep onset in insomnia patients. Accordingly, one aspect of the technology is to provide a forehead cooling system 2000 configured to reduce the temperature of the patient’s forehead in use.

[0413] In some examples the forehead cooling system 2000 may be incorporated in a system for treatment of sleep disordered breathing and/or insomnia. For example, the forehead cooling system may be incorporated into, or configured to attach to a patient interface 3000, a positioning and stabilising structure 3300 for a patient interface 3000, and/or an air circuit 4170 configured to deliver a flow of breathable gas to a patient interface 3000.

[0414] In some examples of the technology discussed herein, these forehead cooling systems may use a flow of air, for example from the RPT device 4000, or expired air from the patient’s airways as a means for cooling the patient’s forehead. For example, this flow of air may be directed onto or across the surface of the patient’s forehead to remove heat from the patient’s forehead, for example by using convection.

[0415] In examples of the technology where a humidifier 5000 is used, the flow of air may be humidified to further aid in reducing the temperature of the patient’s forehead.

[0416] In other examples of the technology, a liquid forehead cooling system 2000 may be provided. These systems are configured to facilitate the transfer of heat from the forehead of a patient, for example by using conductive cooling. [0417] In yet further examples of the technology, an active forehead cooling system 2000 may be provided, for example by using a Peltier cooler.

[0418] In one example of the technology, the system may include components such as a heat exchanger, an evaporative cooler, or active components such as a Peltier cooler. Some examples of heat and/or humidity exchangers which may be used with the present technology are described in PCT Publication No. WO/2013/067592 which is herein incorporated in its entirety by reference.

[0419] It should be appreciated that in the examples described herein, any one or more of these technologies may be used independently or in combination to provide forehead cooling functionality.

[0420] While the present technology is primarily described in relation to assisting with the treatment of insomnia, it is believed that this technology may also be beneficial in assisting with treatment of other disorders such as treating dyspnoea, menopausal symptoms, hypertension, anxiety, hyperthyroidism, anhidrosis, diabetes, migraines, and chronic pain. In other examples the technology may provide benefits in sleeping comfort, such as during pregnancy, and the luteal phase of the menstrual cycle.

5.8.1 Forehead Cooling Technologies

5.8.1.1 Air Cooling

[0421] With reference to Fig. 8 A a patient interface 3000 is provided with a forehead cooling system 2000. The forehead cooling system 2000 is connected to and supported by the positioning and stabilising structure 3300. For example, the forehead cooling system may comprise a first end 2002, connected to and supported by a first side 4171 of the positioning and stabilising structure 3300, and a second end 2004 connected to and supported by a second side 4172 of the positioning and stabilising structure 3300.

[0422] In the illustrated example, the forehead cooling system 2000 connected to the positioning and stabilising structure 3300 in a location which is superior to the eyes of the patient, so as to minimise any potential obscuring of the patient’s field of view. The forehead cooling system 2000 is also positioned such that there is a gap 2006 between the connection port 3600 on the top of the patient’s head and the forehead cooling system 2000, this gap may advantageously allow the patient’s hair to extend through the gap potentially increasing comfort and reducing irritation. [0423] The forehead cooling system 2000 may be positioned and attached to the positioning and stabilising structure, using any suitable methods such as mounting to one or more straps as described herein.

[0424] The forehead cooling system 2000 may be configured to attach to the positioning and stabilising structure 3300 such as being releasably attached, using one or more fasteners, such as clips, buckles or hook and loop fasteners. In some examples, the forehead cooling system 2000 may be releasably attached to one side of the positioning and stabilising structure 3300, and non-releasably attached to the other side. In other examples of the technology the forehead cooling system may be non- removably joined to the positioning and stabilising structure 3300.

[0425] In some examples the forehead cooling system 2000 may be attached to the positioning and stabilising structure 3300 with an adjustment mechanism, such as a hook and loop fastener or buckle (not shown) to allow the patient to adjust the force which is applied to the patient’s forehead in use. In addition, the forehead cooling system may include an extensible material such as an elastic or elastane material to allow the forehead cooling system 2000 to remain in contact with the forehead of the patient in a range of sleeping positions.

[0426] In some examples the forehead cooling system 2000 may be configured to be fluidly connected to the patient interface 3000 or the air circuit 4170. For example, airflow through the patient interface 3000, and/or air circuit 4170 may be used to cool the patient’s forehead in use as is described herein. In the example of Fig. 8 A the forehead cooling system 2000 may be fluidly connected to the first side 4171 of the positioning and stabilising structure 3300, and/or the second side 4172 of the positioning and stabilising structure, such that the airflow received through the connection port 3600 passes through the forehead cooling system 2000, or otherwise causes airflow within the forehead cooling system 2000 (for example by using the venturi effect), removing heat from the forehead region of the patient.

[0427] For example, the forehead cooling system 2000 may be fluidly connected at a first end 2002 to the first side 4171 of the positioning and stabilising structure 3000 such that airflow from the connection port 3600 to the patient interface is fluidly coupled to the forehead cooling system 2000. The second end 2004 may be configured to draw in air from the surrounding environment (for example using the venturi effect). This can advantageously draw in cooler and/or dryer air than what may be provided by an RPT device 4000, particularly where a heated/humidified air supply or air circuit 4170 is used. To prevent air from venting out of the second end 2004, a one-way valve may be used which allows air to be drawn in, without allowing air to vent out. Examples of suitable valves should be familiar to those skilled in the art.

[0428] For example, Fig. 8B shows a cross-sectional view of a forehead cooling system 2000 in the form of a fluid conduit 8005 which may be fluidly coupled to the patient interface 3000 and/or RPT device 4000. For example, as described herein the positioning and stabilising structure 3300 may include conduit headgear, though which a flow of pressurised breathable gas is provided in use. For example, the flow of pressurised breathable gas generated by the RPT device 4000, may be routed through the fluid conduit of the forehead cooling system 2000, to cool the forehead of the patient in use.

[0429] In one example the fluid conduit 8005 may comprises or be constructed entirely of a textile. Examples of textile conduits are described in more detail in PCT publication No. WO2012167327A1 published 13 December 2012, the entire contents of which are herein incorporated by reference.

[0430] The use of a textile may advantageously improve patient comfort, and by extension respiratory therapy compliance.

[0431] In one example of the technology, the flow of breathable gas passing through the forehead cooling system 2000, may be sufficient to cool the forehead region of the patient, for example by convective cooling. In some examples of the technology, the materials used in the fluid conduit 8005 may be selected to include at least one material having a relatively high thermal conductivity, such as being greater than 0.5 W/m.K. For example, the fluid conduit may comprise a thermally conductive silicone such as a carbon impregnated silicone, or one or more metals, such as thin flexible metallic strands or layers.

[0432] In some examples of the technology, the fluid conduit 8005 may comprise a semi-permeable material configured to vent a flow of air received from the connection port 3600 onto the forehead of the patient in order to cool the forehead. For example, the fluid conduit 8005 material may be configured to allow some amount of the flow of breathable gas to pass through the conduit and onto the forehead region of the patient. For example, the fluid conduit 8005 may be configured to allow airflow to pass through. For example, the fluid conduit 8005 may comprise one or more holes 8007 configured to allow the flow of breathable gas to pass therethrough. By using holes 8007 it may be possible to direct airflow to specific regions of the forehead in order to have greater control over what is being cooled, and the rate of cooling (for example by controlling the number of holes, and hole sizes). For example, the fluid conduit 8005 may have between 3 and 100 holes 8007 provided along a length of the fluid conduit 8005, such as between approximately 10 and 50 holes 8007.

[0433] In other examples the fluid conduit 8005 may be constructed of a breathable material, which allows some airflow to pass therethrough. For example, the fluid conduit 8005 may be constructed of a textile, and airflow may be provided between the interstices between fibres or yarns of the textile, and/or the fibres or yams may allow some airflow to pass therethrough.

[0434] In other examples of the technology the forehead cooling system 2000 may be configured to remain in contact with the forehead of the patient and to remove heat from the forehead by transferring the forehead heat into the flow of air, before subsequently passing the heated air to the airways of the patient for breathing. As should be familiar to those skilled in the art, heating the flow of breathable gas/air prior to inhalation by the patient can improve comfort and compliance of respiratory pressure therapy systems.

[0435] In one example shown in Fig, 8C a forehead cooling system 2000 is provided which includes a conduit 8005 having a patient contacting layer 8009 configured to be in contact with the forehead of the patient in use and draw heat away from the forehead of the patient in use. For example, this patient contacting layer 8009 may be constructed of a thermally conductive material as described herein.

[0436] In some examples of the technology described herein the patient contacting layer 8009 may be a thermoelectric cooler 5005.

[0437] Attached to the patient contacting layer is the fluid conduit 8005 which is configured to receive a fluid flow, such as a flow of breathable gas. This fluid flow in some examples is a liquid such as water, and in other examples it may be a breathable gas such as air/oxygen. This fluid flow may advantageously be used to draw heat away from the patient contacting layer, and therefore cool the forehead of the patient. [0438] The patient contacting layer 8009 in some examples may form one of the walls of the fluid conduit 8005, in other examples such as is shown in Fig. 8C the patient contacting layer 8009 may be attached to an interfacing layer 8011 between the patient contacting layer 8009 and the fluid flow ‘F’ through the fluid conduit 8005. For example, it may be preferable to manufacture the fluid conduit 8005 separately from the patient contacting layer 8009 and attach the fluid conduit 8005 to the patient contacting layer using one or more fasteners such as an adhesive. In this example the interfacing layer 8011 acts as one of the walls of the fluid conduit 8005. The interfacing layer 8011 may further be configured to be more porous (i.e., have more holes, or larger diameter holes 8007) or have a greater thermal conductivity than other materials (such as textile materials) used in the fluid conduit 8005, in some examples described herein this interfacing layer 8011 may be a thermal interface material 6002 as is described in greater detail in relation to Fig. 12A.

[0439] In some examples of the technology, it can be advantageous to monitor and/or control the temperature of the forehead cooling system 2000, and or forehead of the patient. As such in some examples of the technology, the forehead cooling system 2000 may comprise one or more sensors 8013, such as temperature, moisture, heart rate or EEG sensors. These sensors 8013 may be used to provide information on the efficacy of the forehead cooling system 2000, or otherwise be used to provide feedback as to whether forehead cooling is required. It should be appreciated that these sensors 8013 may be communicatively coupled with a processor, such as via a wired or wireless connection. For example, the processor may be provided in an RPT 4000, or a personal computing device, such as a smart phone or computer. Further examples of monitoring systems are described herein.

5.8.1.2 Fluid Cooling

[0440] In one example of the technology shown in Fig. 9 a forehead cooling system 2000 is provided which comprises a fluid transfer system 3001 configured to transfer heat away from the forehead of the patient 1000, for example using thermal conduction. While this system is shown schematically for simplicity, it should be appreciated that it may be attached or otherwise mounted to a patient interface 3000 such as being mounted to the positioning and stabilising structure 3300 as described herein.

[0441] The fluid transfer system 3001 may comprise a reservoir 3002 such as a bladder which is configured to receive a volume of fluid such as water, oil, or air in use. The reservoir 3002 may comprise an inlet 3004 configured to receive the flow of fluid, and an outlet 3006, configured to transfer fluid out of the reservoir, for example for cooling or recirculation via a pump 3008. [0442] In some examples of the technology the pump 3008 may be a peristaltic pump or any other suitable fluid pump, for example the pump 3008 may be a blower, for example where the fluid is air. In some examples of the technology the blower may a blower contained within an RPT device 4000 which is configured to generate the flow of breathable air to the airways of the patient for treatment of sleep apnoea. [0443] In some examples of the technology, the reservoir 3002 may be flexible to allow the reservoir 3002 to conform to the forehead of the patient, i.e. a flexible fluid bladder such as a plastic bladder made from a flexible material such as a poly vinyl chloride or thermoplastic urethane. In other examples, the reservoir may be configured to thermally connect to the forehead of the patient via a thermal interface material 6002 as is discussed later in relation to Fig. 12A.

[0444] In some examples of the technology the reservoir 3002 may contain a gel 3010 material such as one or more gel beads. For example, the gel may comprise sodium polyacrylate or any other suitable gel. The use of a gel may advantageously increase the heat transfer characteristics of the forehead cooling system 2000, such as by providing a higher thermal conductivity than fluids such as oil or water alone, or by increasing the heat capacity of the heat transfer medium (with respect to oil or water alone).

[0445] In some examples of the technology, such as examples in which the forehead cooling system is removable, the reservoir 3002 may be cooled in a refrigerator prior to use, in order to provide a rapid temperature reduction to aid in sleep onset. Accordingly, one aspect of the technology is to provide a forehead cooling system 2000 which is able to be removed from a positioning and stabilising structure 3300 and cooled prior to use to assist with sleep onset.

[0446] In some examples of the technology the reservoir 3002 may contain a phase change material (PCM) such as a sodium acetate trihydrate. In use this phase change material may be heated to a liquid, and in use activated using a flexing process or by snapping a metal disc inside the reservoir to convert the PCM from its liquid state to a solid state, resulting in a cooling effect. The PCM material can then be prepared for the following sleep session by heating the liquid once more to convert the PCM from a solid to a liquid. It should be appreciated that in examples of the technology where a PCM material is used, a pump 3008 is not required, and the forehead cooling system 2000 may simply comprise a reservoir of the PCM material which is held in position on the patient’s forehead. [0447] Fig. 10 shows an example of the forehead cooling technology of Fig. 9 in engagement with the forehead of a patient 1000. In this example the reservoir 3002 is supported in engagement with the forehead of the patient 1000 using the positioning and stabilising structure 3300. For example, the reservoir may be attached to one or more straps or conduits on either side of the patient’s head.

[0448] Accordingly, by combining forehead cooling systems 2000 with patient interfaces it may be possible to take advantage of the positioning and stabilising structure 3300 used to position and stabilise the patient interface in engagement with the patient’s face. Similarly, it may be possible to treat a patient for comorbid insomnia and sleep apnea simultaneously in one system.

5.8.1.3 Thermoelectric Cooling

[0449] Fig. 11 shows one example of the technology in which a radiator 5000 is provided to transfer heat between a fluid within the forehead cooling systems 2000 and the surrounding, ambient air. In one example a heatsink 5006 is mounted to a fluid conduit 5002 in order to transfer or radiate heat from the fluid conduit, into the surrounding environment. As in previous examples the fluid conduit may also comprise an inlet 3004 and an outlet 3006 which may be connected to a pump 3008 or blower for circulation of the fluid.

[0450] In some examples of the technology a thermoelectric cooler 5005 may be provided, such as a Peltier cooler. Thermoelectric coolers 5005 allow for simultaneous heating and cooling. As a voltage is applied to the cooler 5005, the temperature of a first side 5005A decreases while the temperature of a second side 5005B increases. The heated and cooled sides of the thermoelectric cooler may be switched by applying an opposite polarity voltage.

[0451] In one example of the technology, a thermoelectric cooler 5005 may have a first side 5005A configured to engage the fluid conduit 5002 to cool the fluid conduit 5002 in use, and a second side 5005B either configured to contact the ambient air, or in some cases attach to a heatsink 5006 which is in fluid communication with the ambient air, in order to dissipate heat from the thermoelectric cooler.

[0452] In some examples a fan or other blower may also be provided to improve the air circulation over any one or more of the fluid conduits 5002, thermoelectric cooler 5005 and/or heatsink 5006. For example, the fan or blower may be an axial fan, radial fan, or a piezo blower. In some examples the blower may be provided by the RPT device 4000 for example, the air may be circulation may be provided by the airflow drawn into the RPT device 4000, for example from an intake, while in other examples the airflow may be provided by air exhausted through a vent 3450 or other similar structure such as an anti-asphyxia valve.

[0453] In the illustrated example of Fig. 11 the fluid conduit 5002 may be configured to expand from an inlet 3004 or outlet 3006 as described herein to provide an increased surface area for thermal heat transfer. For example, the fluid conduit 5002 may have a substantially rectangular central portion 5008 dimensioned to receive the thermoelectric cooler 5005. Between the substantially rectangular central portion 5008, and the inlet 3004 or outlet 3006, the fluid conduit may include a gradual taper 5010 to thereby minimise or reduce the fluid turbulence within the fluid conduit 5002.

[0454] In other examples of the technology, the heatsink 5006, and/or thermoelectric cooler 5005 may be configured to mount directly to the reservoir, or to the forehead of the patient in use, such as is shown in Fig. 8.

[0455] In the example of Fig. 12A the thermoelectric cooler 5005, is configured to thermally connect to the forehead of the patient, in some examples via a thermal interface material 6002. For example, the thermal interface material 6002 may be a gel or elastomer such as a biocompatible silicone. The use of a gel or elastomer may advantageously increase the rate of thermal transfer of heat from the forehead of the patient into the reservoir or thermoelectric cooler 5005. In some examples the thermal interface material may further act as a cushioning element which can at least partially conform to the head shape of the patient, thereby improving patient comfort.

[0456] On the opposing side of the thermoelectric cooler 5005 is a heatsink which is optionally connected to the thermoelectric cooler 5005 by a further thermal interface material 6002. It should be appreciated that the thermal interface material 6002 used for the heatsink does not need to have the same comfort and biocompatibility requirements as the patient contacting thermal interface material. For example, this thermal interface material may comprise a metal oxide.

5.8.1.4 Air Assisted Heatsinking

[0457] In some embodiments airflow may be directed towards the forehead of the patient. For example, this airflow may be provided by vented air from the patient interface, air supplied from the RPT device 4000, or air which has been drawn into the RPT device for example via an intake. In other examples, a thermal interface material 6002 may be positioned on the forehead of the patient, and the vent 3400 flow (or a portion of the vent flow) may be directed towards an outwardly (not-patient contacting) surface of the thermal interface material 6002.

[0458] The thermal interface material 6002, may conduct heat from the forehead to the vented airflow and on to the atmosphere. In some embodiments the ambient side of the thermal interface material 6002 may include design features to increase the surface area exposed to the flow path, for example the design feature may take the form of ridges or fins in the material. This thermal interface material 6002may therefore act as a heatsink.

[0459] In some embodiments, the heat conductive material may be made up of a composite of different materials, for example, the conductive material may be designed in a layered arrangement, such that a layer in contact with the forehead may have different properties than a layer exposed to the atmosphere. In this way the contact layer material may be particularly chosen to be bio-compatible with the forehead, and the properties of the material may be designed for greater comfort, for example, the hardness of the material of the layer in contact the forehead may be significantly lower than other layers of the conductive material.

[0460] In some forms of the technology, it may be advantageous to pass a fluid across the surface of a heatsink to further remove heat from the system. For example, the fluid may be from a reservoir as described herein, or alternatively when the forehead cooling technology is used in combination with a PAP system, airflow from the PAP system may be used to transfer heat away from the heatsink.

[0461] For example, a flow of pressurised air from an RPT device 4000 may be configured to pass over the heatsink to draw heat away from the heatsink and therefore the forehead of the patient. In other examples, the air vented from the patient interface may be configured to draw heat away from the heatsink and therefore the forehead of the patient. For example, with reference to Fig. 12B the patient interface 3000 may be configured to vent air ‘A’ out of the patient interface 3000 toward the forehead of the patient, such as by directing the flow of vented air from the patient interface 3000 in a superior direction toward the forehead. As described herein this vented air may be used to cool a forehead cooler 2000 such as a thermoelectric cooler 5005. [0462] Similarly with reference to Fig. 8A, the forehead cooling system 2000 may be configured to draw air from any one or more of the air circuits 4170 for cooling the forehead and/or heatsink described herein.

[0463] Accordingly, one aspect of the technology is to utilise the air flow from a vent in the patient interface 3000 to power or assist a system to provide forehead cooling to the patient.

[0464] The inventions described in any of the previously described embodiments may also be adapted for use without PAP therapy by replacing the PAP vent flow with any alternative source of airflow, such as an alternative blower of fan, or from a source of compressed air. In some embodiments the flow rate may be controlled to control the amount of heat exchange. As with previous embodiments, this can be used as a means of achieving a particular temperature profile with time, or as part of a control loop to target particular physiological effects.

5.8.1.5 Evaporative Cooling

[0465] In some embodiments increased cooling performance may be achieved by employing principals of evaporative cooling. In some embodiments a layer of the conductive medium exposed to airflow may be made of a porous material or an absorbent material, such that it may be soaked with water (or other fluid) before bedtime, and when exposed to the airflow the water may start evaporating, in this way heat can be removed from the layer at a greater rate as energy is taken by the liquid molecules as they change phase from liquid to solid. In some embodiments the system may be fitted with a reservoir to replenish liquid as it evaporates. In some embodiments there may be a wick material connecting the reservoir to the layer exposed to the airpath that can transport liquid from the reservoir.

5.8.2 Cooling Control

[0466] Fig. 13 shows one example of a state machine for control of the forehead temperature of a patient. In the illustrated example the state machine relates to a thermoelectric cooler 5005, however this should not be seen as limiting and the logic for the activation and deactivation of the thermoelectric cooler could instead be applied to control the flow of a fluid, or venting of air towards the forehead of the patient. [0467] With reference to Fig. 13, when the RPT device 4000 is turned on the thermoelectric cooler 5005 may be configured to transition from an off state wherein the thermoelectric cooler is inactive, to an operating state wherein the thermoelectric cooler is actively cooling the forehead of the patient 1000.

[0468] Should the ambient temperature, or forehead temperature of the patient drop below a predetermined set temperature such as between 18 and 25 degrees Celsius, such as approximately 20 degrees Celsius, the thermoelectric cooler 5005 may be configured to shut down or otherwise become inactive until the ambient temperature or forehead temperature rises above the predetermined set temperature again. For example, the system may include a temperature sensor 8013 configured to provide a measurement of the temperature of the patient’s forehead or a region adjacent to the patient’s forehead.

[0469] In some examples the thermoelectric cooler 5005 may be configured to have a second predetermined set temperature at which the operation of the thermoelectric cooler decreases to provide a reduced rate of cooling, for example the second predetermined set temperature may be between approximately 20 and 22 degrees Celsius, such that the thermoelectric cooler 5005 operates at a reduced rate between the first predetermined set temperature, and the second predetermined set temperature. Above the second predetermined set temperature, the thermoelectric cooler 5005 may be configured to operate in a normal, full-power mode.

[0470] The forehead of a patient may typically be between 33-37 degrees Centigrade, and the present technology may be configured to reduce the forehead temperature to a temperature in the mid to high teens, such as 14 to 18 degrees Centigrade, or more preferably approximately 14 or 15 degrees Centigrade.

[0471] In some examples of the technology, it may not be practical to reduce the forehead temperature to 14-18 degrees Centigrade. For example, due to reaching thermodynamic constraints of the cooling method used or power, noise, size, or cost limitations. Accordingly, it can be advantageous to provide any reduction in forehead temperature below body temperature, including for example temperatures of approximately 20-30 degrees Celsius.

[0472] In one example, the technology is configured to reduce the forehead temperature for the period leading to sleep onset only. While in other examples, the technology may be used for the duration of the patient’s sleep or parts thereof. [0473] In some examples of the technology, such as in cool environments the heat transfer techniques may be used to transfer heat to the forehead, or any other body part.

[0474] In some examples of the technology, the cooling technologies described herein may be used to transfer heat away from, or otherwise cool other parts of the patient’s body. For example, as a treatment for injury or pain such as muscle pain caused by overuse.

[0475] In some embodiments a temperature sensor or array of sensors, such as a thermocouple may be embedded into, or in contact with one of the layers of conductive material, or in contact with the forehead to sense the forehead temperature. In some embodiments a control loop may be established to target a specific temperature, or a specific temperature profile. For example, the vent flow rate may be automatically increased or reduced to achieve a target temperature or temperature profile.

[0476] In some embodiments the apparatus may include sensors 8013 that include EEG, ECG, and/or EMG sensing, and parameters from these signals may be used as control targets, for example, forehead cooling may be applied to reduce frontal cortex brain activity, or heart rate. In some embodiments cooling may be increased or decreased in the presence of rapid eye movement.

In other examples the systems designed herein may be configured to determine sleep onset by analysing the patient’s breathing waveforms, and controlling the forehead cooling system such as disabling the cooling functionality or reducing the cooling target temperature when sleep onset is detected.

[0477] In some embodiments, the system may be used as part of a broader relaxation procedure, for example, before attempting to sleep the patient may use the system while meditating or practicing deep breathing exercises (or other relaxation techniques), of the system maybe be synchronised with a guided relaxation procedure, such as guided deep breathing, or medication.

5.8.3 Humidification And Cooling

[0478] In another example of the technology, a thermoelectric cooler 5005 may be used both to increase the temperature of a fluid supply for humidification purposes, while simultaneously reducing the temperature of a fluid supply for forehead cooling purposes. For example, with reference to Fig. 14 a thermoelectric cooler 5005 may have a first side 5005A in thermal engagement with a first fluid 8002, and a second side 5005B in thermal engagement with a second fluid 8004. For example, the first fluid may be configured to be in thermal contact with the forehead of a patient, and the second fluid may be intended to be breathed by the patient in use.

[0479] In examples the first fluid may be provided in a first chamber or conduit, and the second fluid may be provided in a second chamber or conduit.

[0480] In one example the first supply of fluid 8002 may be a flow of air to or from the forehead of the patient. For example, the first supply of fluid may be configured to cool the forehead of the patient directly, or indirectly, such as by cooling a heatsink attached to the forehead of the patient. In other examples the first supply of fluid may be a water or oil configured to cool the forehead of the patient via a fluid transfer system as described herein.

[0481] In one example, the second supply of fluid 8004 may be the breathable gas passing through one or more air circuits 4170. In another example the second supply of fluid may comprise water used in the humidification of a flow of air intended to be breathed by the patient, in another example the second supply of fluid may comprise humidified breathable gas.

5.8.4 Vented Airflow Examples

[0482] In some examples of the technology an air circuit 4170 may include a vent 3400 or vent opening 3402 configured to vent expired air out of the PAP system. One example of an air circuit comprising a vent is shown in Fig. 70. A modified version of this air circuit 4170 is shown in Fig. 15A wherein the vent is provided with a conduit 15000 configured to direct the flow of air (generally indicated by arrows A), in a superior direction towards the forehead of the patient. In other words, the air circuit 4170 comprises a conduit 15000 configured to direct a portion of the air flow through the conduit 15000 towards the forehead of the patient in use.

[0483] In the illustrated example, the conduit 15000 is formed of a rigid plastic, and includes a curved outlet 15002, which is provided at an angle with respect to a longitudinal axis ‘L’ of the conduit 15000. This curved outlet 15002 provides some directional control to the flow of vented air, allowing the airflow to be directed back towards the patient’s face and forehead. In some examples the air circuit 4170 may comprise an anti-asphyxia valve (AAV) which is configured to selectively control the venting of air through the conduit 15000. Examples of AAVs can be found in United States Patent Publication No. 2006/0076017 Al published 13 April 2006, and United States Patent Publication No. 2009/0065729A1 published 13 March 2009, the contents of which are herein incorporated by reference in their entirety.

[0484] For example, the AAV may be configured to only vent air through the conduit 15000 during expiration from the patient. In other examples, the air circuit 4170 may be configured to continuously vent air through the conduit 15000 in use.

[0485] Fig. 15B shows a further version of an air circuit 4170 configured to direct a flow of air towards the forehead of a patient. In this example, the conduit is provided on the patient interface side of a decoupling structure 15004, such that the positioning of the conduit remains substantially fixed with respect to the patient interface, while the decoupling structure 15004 allows the air circuit to pivot or rotate about the decoupling structure 15004. Other forms of decoupling structure should be familiar to those skilled in the art, such as a swivel or ball-and-socket joint.

[0486] Fig. 15C shows an example of the air circuit of Fig. 15A or 15B in use with a patient interface 3000 that comprises a nasal seal forming structure 3100. It should be appreciated that the same air circuit 4170 may similarly be used with patient interfaces 3000 that have a seal forming structure 3100 configured to deliver a flow of breathable gas to both the oral and nasal airways of the patient in use.

[0487] As shown, the conduit 15000 extends in an inferior- superior direction, from the air circuit 4170 towards the forehead of the patient. In preferred examples the end of the conduit 15000 sits in a more superior position than the pronasale of the patient’s face to ensure that the flow of air does not disturb or irritate the sensitive regions of the patient’s nose and/or to limit the amount of airflow which passes over the eyes of the patient.

[0488] In the example shown, the conduit 15000 is positioned substantially centrally with respect to the sagittal plane of the patient, this can advantageously prevent or limit the drying or irritation of the eyes of the patient in use, i.e, the flow of vented air is directed between the eyes of the patient and onto the forehead region (in a direction generally indicated by arrows A).

[0489] Figs. 16A and 16B show an alternative example of the technology, in which a conduit 15000 is provided in a patient interface 3000 in order to direct air vented from the patient interface towards the forehead of the patient. Like in previous examples the conduit 15000 may include a curved outlet 15002 configured to provide some directional control to the flow of vented air, allowing the airflow to be directed back towards the patient’s face and forehead (in a direction generally indicated by arrows A). It should be appreciated that in each example the flow of air through the conduit 15000 may be controlled by a vent 3400 as described herein.

[0490] Fig. 16B shows an alternative design of a patient interface 3000 which includes a conduit 15000 configured to direct a flow of air to the forehead region of the patient. In this example the conduit 15000 is adjustably connected to the patient interface, for example via a support structure 15006 comprising a pivot 15008. This configuration may advantageously allow the direction of airflow to be adjusted to account for anthropomorphic variations between patients.

[0491] In Fig. 16B the conduit is also provided in a spaced relationship with respect to the patient interface 3000. This may allow for the rate of flow to be adjusted easily by orienting the conduit to adjust the amount of airflow picked up from the vent 3450 (not shown in this example). This space relationship may also encourage air entrainment from the surrounding atmosphere, such that the flow of air delivered to the forehead of the patient is a mixture of vented air and ambient air. As the vented air may be heated by the patient’s breath, and/or the RPT device 4000, the act of combining ambient air may advantageously result in a cooler flow of air to further assist with cooling the forehead of the patient.

[0492] Fig. 16C shows a rear view of the patient interfaces of either Fig. 16A or 16B, in each of these examples the patient interface 3000 comprises a shell 3210 which may be constructed of a plastic such as a polycarbonate. Connected to the shell 3210 is a seal forming structure 3100 configured to deliver a flow of breathable gas to the nasal and oral airways of the patient.

[0493] The seal forming structure 3100 in this example includes a nasal portion 3230, which in use is configured to engage with the surfaces on the underside of the patients nose, e.g., against the pronasale towards the anterior direction, the nasal ala on either lateral side and the lip superior and an oral portion 3260 configured to seal around the oral airways of the patient in use.

[0494] Further examples of this type of patient interface are described in PCT Publication No. WO2019183680A1, published on 3 October 2019, the contents of which are herein incorporated by reference in their entirety.

[0495] In the illustrated examples, the conduit 15000 extends from the shell 3210 of the patient interface 3000, either via a direct connection to the shell 3210 (including being attached to, removably connected to, or moulded as part of the shell) or by being in a spaced relationship with respect to the shell 3210. In these examples the shell 3210 may be similarly constructed of a rigid plastic such as a polycarbonate or other suitable plastic material. This may advantageously provide an airflow path between the plenum chamber 3200 and the forehead of the patient.

[0496] Fig. 17A illustrates a further example of a ‘tube-up’ system which is substantially the same as the system described in relation to Fig 7L. However, in this example, a flow diverter 17000 is attached to the connection port 3600 in order to direct a flow of air in an anterior-inferior direction to the forehead of the patient (in a direction generally indicated by arrows A). The flow diverter includes a conduit 15000 which is curved to follow the contour of the patient’s head and direct the flow of air in an anterior-inferior direction onto the forehead of the patient in use.

[0497] In some examples, this flow diverter 17000 may be a removable component which is removably attached to the connection port 3600. For example, the flow diverter 17000 may be positioned between the connection port 3600 and the air circuit 4170 (not shown in Fig. 17A) to receive a flow of air from the RPT device 4000 and direct the flow of air onto the forehead of the patient.

[0498] In other examples, the flow diverter 17000 may be provided as part of the connection port 3600. In other words, the connection port 3600 may comprise a conduit 15000 configured to direct a flow of air toward the forehead of the patient.

[0499] Fig. 17B shows a further example of a flow diverter 17000 which may be connected to the connection port 3600. In this example the conduit 15000 is a flexible tube, which may be repositioned as necessary to direct the flow of air onto the desired regions of the patient’s forehead. In some examples it may be advantageous for the conduit 15000 to retain its shape after being bent in to the desired configuration, in other words the materials of the conduit may be selected to provide shape retention characteristics. For example, this may be provided by flexible metal tubing such as bendable copper or aluminium tubing, or the conduit may include a concertina or gooseneck section as is common in plastic drinking straw in other examples the conduit may be provided with one or more swivelling connectors allowing one or more sections of the conduit to be manipulated with respect to the other sections.

[0500] In this example, the positioning and stabilising structure 3300 may include one or more mounts 17002 for retaining the conduit 15000. For example, the mounts 17002 may be clips having a receptacle configured to receive the conduit 15000, or may offer any other suitable form of fastening, such as be using hook and loop fasteners, domes and buckles.

[0501] Fig. 17C shows a further example of a tube up configuration which has a similar overall structure to Figs. 17 and 7L. In this example however the positioning and stabilising structure 3300 comprises a pair of opposing conduits 15000 configured to direct the flow of air from opposing sides 4171, 4172 of the positioning and stabilising structure 3300 inwardly towards the forehead of the patient (in a direction generally indicated by arrows A). It should be appreciated that in some examples only a single conduit may be used, for example the positioning and stabilising structure 3300 may be configured to direct a flow of air from one side of the positioning and stabilising structure.

5.8.4.1 Compact Vent Design

[0502] Figs. 18A to 18C show an example of a flow adjustable compact vent 3450 configured to direct a flow of air from the patient interface 3000 towards the forehead of the patient.

[0503] In this example the vent 3450 comprises a central component 3456 and an outer housing 3466. A primary vent pathway is provided between the gap 3464 between the central component 3456 and the outer housing 3466. The flow through this gap be configured by appropriately setting the size of this gap.

[0504] An aperture 18002 is provided in a sidewall or groove 3416 of the outer component, such that when connected to the patient interface, this aperture 18002 faces towards the forehead of the patient and acts as a conduit which directs a portion of the vented airflow through the sidewall 3416 towards the forehead of the patient in use.

[0505] In some examples the central component 3456 may be rotatably connected to the outer housing 3466, and may include one or more flow control apertures 18000, for example there may be flow control apertures of varying size such as is illustrated in Fig. 18C. In use, rotation of this central component 3456 adjusts which of the flow control apertures 18000 is aligned with the aperture 18002 in the outer housing 3466, with larger apertures resulting in increased airflow, and smaller apertures (or rotating the central component to a position where no apertures are aligned) result in a reduced or restricted airflow. Therefore, by rotating the central component with respect to the outer housing 3466 it may be possible to adjust the airflow directed towards the forehead of the patient as illustrated in Fig. 18 A.

5.8.5 Other Examples

[0506] Fig. 19A shows an example of a system 19000 which includes a patient interface 3000 and positioning and stabilising structure 3300 which are configured to operate as a standalone unit for the delivery of a flow of breathable gases to the airways of the patient. The system includes a power source 6030 such as a battery, and a flow generator 6400 configured to generate the flow of breathable gases to the airways of the patient via a seal forming structure 3100. Further details on these types of systems can be found in PCT application No. PCT/AU2024/050419 filed on 2 May 2024the entire contents of which are herein incorporated by reference in its entirety. [0507] In this example the system 19000 comprises a conduit 15000 which is fluidly connected to the flow generator 6400 and is configured to direct a flow of air from the flow generator 6400 in a superior-posterior direction towards the forehead of the patient (in a direction generally indicated by arrows A).

[0508] In another example, the conduit 15000 may be configured to act as an intake and draw ambient air into the flow generator 6400. By angling this conduit towards the forehead of the user, this intake may cause the incoming air to be drawn in an anterior-inferior direction from the forehead area of the patient, thereby cooling the forehead of the patient in use.

[0509] In other examples, airflow may be directed towards, or drawn from the forehead region of the patient using any of the methods described herein, including for example using one or more conduits mounted to the positioning and stabilising structure 3300 as illustrated in Fig. 19B. For example the conduit may be fluidly connected to the flow generator 6400 via one or more air circuits (such as a textile air circuit) within or attached to the positioning and stabilising structure.

[0510] Fig. 20A shows another example of the technology which can incorporate a flow generator 6400 configured to generate a flow of breathable gas, a seal-forming structure 3100 to deliver the flow of breathable gas to the airways of the patient and a positioning and stabilising structure 3300 configured to support these components on the patient’s head in use. In this example the power source 6020 is provided via a cable such as from an external battery, or power supply such as a USB port or plug pack. [0511] In this example of the technology the positioning and stabilising structure 3300 comprises a headband, hoop 8378 or ring which is configured to extend around the patient’s head from the patient’s frontal bone to the patient’s occipital bone. In the illustrated example, the hoop 8378 may be a continuous piece of material, although in other examples, the hoop 8378 may include multiple pieces that allow for adjustment of the length of the hoop 8378.

[0512] In use the hoop structure is configured to rest upon the patient’s forehead, and as such may be provided with any of the forehead cooling systems 2000 described herein including but not limited to air or fluid cooling systems, PCM materials, and thermoelectric cooling systems.

[0513] In some examples this hoop 8378 may be provided with one or more sensors 8013 configured to measure one or more characteristic of the patient. For example, this may include temperature, moisture, heart rate or EEG sensors. These sensors 8013 may be configured to relay the patient information to a controller to control any one or more of the operating parameters of the system, such as the active cooling of the forehead region, or the flow characteristics.

[0514] While not an essential component of the invention, the device in this example also includes an audio system 6800 which includes a pair of output devices 6804. Each output device 6804 may output sound to one of the patient’s ears. In the illustrated example, the output devices 6804 are formed as earmuffs and may rest against and/or enclose each of the patient’s ears. In other examples (not shown), the output devices 6804 may be earbuds that fit within the patient’s ears. These audio systems can be integrated with the control systems described herein to provide auditory stimulus to assist with sleep onset, such as white noise, as well as auditory stimulus to assist with waking the patient, such as alarms, or nature sounds at the appropriate time, or at the appropriate part of the patient’s sleep cycle, such as during light sleep.

[0515] Further details on these types of systems and devices can be found in PCT application No. PCT/AU2024/050419 filed on 2 May 2024 the entire contents of which are herein incorporated by reference in its entirety.

[0516] Fig. 20B shows another form of the technology in which the forehead cooling systems 2000 described herein may be provided in the absence of respiratory treatment technologies. For example, any one or more of the forehead cooling systems 2000 may be provided in a positioning and stabilising structure 3300 such as a headband or hoop 8378.

[0517] Fig. 20C shows a top-down view of a forehead cooling system 2000 provided in engagement with the forehead of a patient 1000. In this example the forehead cooling system includes a housing 20002 which is attached to a positioning and stabilising structure 3300. The housing includes a blower 20004 which is configured to circulate a flow of air through the housing in order to cool the forehead of the user in use. The blower 20004 may be an axial blower, piezo blower, or any other form of blower familiar to those skilled in the art.

[0518] The housing is provided with an inlet 20006 and one or more outlets 20008A, 20008B through which the flow of air passes in use. This airflow can be in either direction, i.e., drawn in across the forehead of the patient and expelled outwardly such as in a superior or anterior direction with respect to the patient’s head, or drawn in from the front of the patients forehead, passed across the forehead and expelled in lateral directions with respect to the forehead.

[0519] In some examples, the forehead cooling system may further comprise one or more sensors 8013 configured to measure the moisture, temperature, heart rate or provide electroencephalogram (EEG) information about the user. For example the sensors may include thermocouples, EEG electrodes and/or EOG (electrooculogram) electrodes.

[0520] Control of the forehead cooling system 2000 may be performed using any of the methods described herein. For example, in one embodiment the forehead cooling system 2000 may adjust the flow of the blower 20004 to maintain a target forehead temperature.

[0521] In some examples it may be beneficial to determine a sleep state of the patient and then set the target temperature control accordingly. For example prior to sleep onset it may be advantageous to provide a low target temperature such as approximately 15 degrees centigrade, and an appropriate blower 20004 speed to reach this temperature. For example the blower 20004 speed may be determined based on the ambient temperature and the forehead temperature of the user, whereby a greater blower 20004 speed is used when the difference between the target temperature and the measured temperature is greatest, and a lower speed used when the temperature differential is lower such as within 0-3 degrees of the target. [0522] Once sleep is detected, it may be beneficial to target a second temperature which is different to the first target temperature. For example, the second temperature may be higher than the temperature used prior to sleep onset. For example, the second temperature may be approximately 20 degrees centigrade. In addition, it may be beneficial to limit the blower 20004 speed so as to reduce the noise and vibration produced.

[0523] In some examples of the technology, it may be beneficial to set the target temperature and/or blower 20004 speed based on the sleep depth of the user. For example, a lower set temperature may be used when a warm forehead is detected, or for example when higher levels of brain activity are detected. Furthermore, it may be beneficial to set the target temperatures and fan speeds based on detecting sleep states such as any one or more of the wake, Nl, N2, N3, or REM sleep states. For example, a first target temperature in the wake sleep state, a second target temperature in the N 1 sleep state, a third target temperature in the N2 sleep state, a fourth target temperature in the N3 sleep state and a fifth target temperature in the REM sleep state.

[0524] In some examples of the technology, it may be beneficial to control the blower speed, or in the case of thermoelectric coolers, the cooling power based on the ambient temperature in the environment.

[0525] In some examples it may further be beneficial to estimate a heat transfer rate based on the measured or estimated forehead temperature, and changes thereof in response to target temperature changes and/or blower speed changes. The estimated heat transfer rate may then be used to adjust the blower speed, or in the case of thermoelectric coolers, the cooling power based on the estimated heat transfer rate/efficacy of the forehead cooling system 2000.

[0526] In some examples the blower speed may be adjusted by adjusting the power or control (such as PWM control) to the blower 20004. In other examples flow path may be modified using a flow diverter. In other words the inlet 20006 and or outlets 20008A, 20008B may be modified to control the effective cooling of the forehead in use.

[0527] Fig. 21 A and 2 IB show another form of the technology in which the forehead cooling systems 2000 described herein may be applied to other applications such as virtual reality (VR), augmented reality (AR), and mixed reality (XR) systems, referred to herein as VR devices for simplicity. In this example a VR device 12000 includes a flow generator 6400 configured to generate a flow of breathable gas to the airways of a patient via a seal forming structure 3100, together with typical features of VR devices such as a display 12070 configured to present an image or video feed for the patient to view during therapy.

[0528] As the VR device 12000 includes a forehead support 12100, this support may be adapted to include one or more sensors 8013 or forehead cooling systems 2000 as described herein. For example a thermoelectric cooler may be positioned in contact with the forehead, and or one or more sensors may be used to monitor the forehead condition/temperature in use. As the VR device 12000 is already positioned in a region which abuts the forehead of the patient, it is possible to incorporate the forehead cooling systems 2000 described herein to simultaneously cool the forehead of the patient.

[0529] In another example part of the airflow generated by or drawn into the flow generator 6400 may be directed towards/drawn from the forehead region of the patient using a conduit 15000 as described herein. In other examples the cushion 12100 which abuts the patient’s forehead may be provided with a PCM material, or thermoelectric cooler as described herein.

[0530] In Fig 21A and 21B, the VR device 12000 comprises a patient interface 3000 however this is not essential to the present technology. For example a VR device 12000 may be provided with a forehead cooling system 2000 without requiring a patient interface.

[0531] It should be appreciated that a number of forehead cooling systems 2000 have been described herein, and any one or more of these systems 2000 may be combined with any of the other systems 2000 described herein. For example, the contact forehead cooling systems described in relation to any one of Figs. 8A to 14, 20A or 20B may be combined with any of the non-contact forehead cooling systems of Figs. 15A to 19B. In other examples a plurality of contact coolers, may be combined such as thermoelectric cooler 5005 and a fluid cooler such as described in relation to Figs. 8A to 10. In yet further examples a plurality of contact-less forehead cooling systems may be combined such as the vent flow from any one of Figs. 15A to 16C, or 18A to 19B with air flow from an air circuit 4170 or connection port 3600 as described in relation to Figs. 17A to 17C.

[0532] Accordingly, one aspect of the present technology relates to an RPT system combining two or more forehead cooling systems 2000 as described herein. 5.8.6 Control Systems

[0533] FIG. 22A depicts an example system 9000 that may be implemented for monitoring sleep providing insights and/or recommendations, and or controlling the operation of a forehead cooling system as described herein. The system 9000 may generally include one or more servers 9010, one or more communication networks 9030, and one or more computing devices 9040. The server 9010 and computing device 9040 may also be in communication with one or more respiratory therapy devices (for example, but not limited to, the RPT device 4000, sensors 8013 and forehead cooling systems 2000 described herein) via the one or more communication networks 9030.

[0534] The one or more communication networks 9030 may comprise, for example, the Internet, a local area network, a wide area network and/or a personal area network implemented over wired communication network(s) 9032, wireless communication network(s) 9034, or a combination thereof (for example, a wired network with a wireless link). In one form, local communication networks may utilize one or more communication standards, such as Bluetooth, Near-Field Communication (NFC), or a consumer infrared protocol.

[0535] The server 9010 may comprise processing facilities represented by one or more processors 9012, memory 9014, and other components typically present in such computing environments. The processing capabilities of the processor 9012 may be provided, for example, by one or more general-purpose processors, one or more special-purpose processors, or cloud computing services providing access to a shared pool of computing resources configured in accordance with desired characteristics, service models, and deployment models. In the example illustrated the memory 9014 stores information accessible by processor 9012, the information including instructions 9016 that may be executed by the processor 9012 and data 9018 that may be retrieved, manipulated or stored by the processor 9012. The memory 9014 may be of any suitable means known in the art, capable of storing information in a manner accessible by the processor 9012, including a computer readable medium, or other medium that stores data that may be read with the aid of an electronic device.

Although the processor 9012 and memory 9014 are illustrated as being within a single unit, it should be appreciated that this is not intended to be limiting, and that the functionality of each as herein described may be performed by multiple processors and memories, that may or may not be remote from each other and the remainder of system 9000.

[0536] The instructions 9016 may include any set of instructions suitable for execution by the processor 9012. For example, the instructions 9016 may be stored as computer code on the computer readable medium. The instructions may be stored in any suitable computer language or format. Data 9018 may be retrieved, stored or modified by processor 9012 in accordance with the instructions 9016. The data 9018 may also be formatted in any suitable computer readable format. Again, while the data is illustrated as being contained at a single location, it should be appreciated that this is not intended to be limiting - the data may be stored in multiple memories or locations. The data 9018 may include one or more databases 9020.

[0537] In some examples, the server 9010 may communicate one-way with computing device(s) 9040 by providing information to one or more of the computing devices 9040, or vice versa. In other embodiments, server 9010 and computing device(s) 9040 may communicate with each other two-way and may share information and/or processing tasks.

5.8.6.1 Computing devices

[0538] The computing device(s) 9040 can be any suitable processing device such as, without limitation, a personal computer such as a desktop or laptop computer 9042, or a mobile computing device such as a smartphone 9044 or tablet 9046. FIG. 22B depicts an exemplary general architecture 9100 of a computing device 9040. The foregoing discussion describes components of the computing device which may be equivalent to or otherwise the same as the components of the server described in relation to Fig. 22A, however for sake of clarity different reference numerals have been used for the components of the computing device.

[0539] Computing device 9040 may include one or more processors 9110. Computing device 9040 may also include memory /data storage 9120, input/output (VO) devices 9130, and communication interface 9150.

[0540] The one or more processors 9110 can include functional components used in the execution of instructions, such as functional components to fetch control instructions from locations such as memory /data storage 9120, decode program instructions, and execute program instructions, and write results of the executed instructions. [0541] Memory/data storage 9120 may be the computing device's internal memory, such as RAM, flash memory or ROM. In some examples, memory/data storage 9120 may also be external memory linked to computing device 9040, such as an SD card, USB flash drive, optical disc, or a remotely located memory (e.g. accessed via a server such as server 9010), for example. In other examples, memory/data storage 9120 can be a combination of external and internal memory. [0542] Memory/data storage 9120 includes processor control instructions 9122 and stored data 9124 that instruct processor 9110 to perform certain tasks, as described herein. As noted above, in examples instructions may be executed by, and data stored in and/or accessed from, resources associated with the server 9010 in communication with the computing device 9040.

[0543] In examples, the input/output (I/O) devices 9130 may include one or more displays 9132. In examples, the display 9132 may be a touch sensitive screen allowing for user input in addition to outputting visible information to a user of computing device 9040. In examples, I/O devices may include other output devices, including one or more speakers 9134, and haptic feedback devices 9136. In examples, the input/output (I/O) devices 9130 may include input devices such as physical input devices 9138 (for example, buttons or switches), sensors 8013, including for example optical sensors 9140 (for example, one or more imaging devices such as a camera), sounds sensors or audio input devices (such as a microphone which allows a patient to control the device using their voice or sounds) and inertial sensors 9142 (particularly in examples where the computing device 9040 is a mobile computing device). It will be appreciated that other I/O devices 9130 may be included, or otherwise accessed through an I/O interface 9150 (for example, interfacing with peripheral devices connected to the computing device 9040). A communication interface 9160 enables computing device 9040 to communicate via the one or more networks 9030.

5.8.6.2 Computer-implementable methods

[0544] Computer readable instructions may implement the exemplary methods described herein. In examples, the computer readable instructions comprise one or more algorithms for execution by one or more of the processors 9012, described herein. The instructions for performing these functions are, optionally, included in a non-transitory computer readable storage medium, for example memory 9014, or other computer program product configured for execution by one or more processors 9012. The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media, or electrical signals transmitted through a wire.

[0545] However, persons of ordinary skill in the art will readily appreciate that the entire algorithm and/or parts thereof can alternatively be executed by a device other than a processor and/or embodied in firmware or dedicated hardware in a well- known manner, e.g., it may be implemented by an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable logic device (FPLD), a field programmable gate array (FPGA), discrete logic, etc. For example, any or all of the components can be implemented by software, hardware, and/or firmware. Also, some or all of the instructions represented by the flowcharts may be implemented manually. Further, although the example algorithms are described with reference to the illustrated flowcharts, persons of ordinary skill in the art will readily appreciate that many other methods of implementing the example processor readable instructions may alternatively be used. For example, the order of execution of the blocks may be changed, and/or some of the blocks described may be changed, eliminated, or combined.

[0546] As used herein the terms “component,” “module,” “system,” or the like, generally refer to a computer-related entity, either hardware (e.g., a circuit), a combination of hardware and software, software, or an entity related to an operational machine with one or more specific functionalities. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a controller, as well as the controller, can be a component. One or more components may reside within a process and/or thread of execution, and a component may be localized on one computer and/or distributed between two or more computers. Further, a “device” can come in the form of specially designed hardware; generalized hardware made specialized by the execution of software thereon that enables the hardware to perform specific function; software stored on a processor readable medium; or a combination thereof.

5.8.6.3 Circadian Rhythm Support

[0547] In examples of the technology, the forehead cooling systems 2000 described herein may be controlled to support a healthy sleep cycle for an individual. For example, the forehead may be actively cooled in the first stages of a sleep cycle to assist with sleep onset. Then the cooling may be paused (or cooling power reduced) once sleep has been detected.

[0548] There are a number of ways in which sleep onset may be detected, including but not limited to monitoring biometric signals from the patient (i.e., using one or more sensors 8013, such as heart rate or EEG sensors) or by monitoring the patient’s breathing waveforms.

[0549] In some examples, the system may be configured to detect situations where the patient wakes during the night, in these examples the system may detect this event and proceed to cool the forehead once more to assist with sleep onset. [0550] In the morning, the forehead cooling systems may be used to assist with waking of the patient, for example in accordance with an alarm set on a mobile device, or as a natural part of the patient’s sleep cycle. For example, where thermoelectric cooling systems are used, the polarity of the voltage may be reversed, and the patient’s head heated to assist with waking the patient.

[0551] Fig. 23 shows one example of a control system configured to control a forehead cooling system as described herein. As shown the system is turned on or activated by the patient. This could be when the device is first turned on, or in the case of RPT devices, when the delivery of pressurised breathable gas is activated. [0552] Once activated, the system is configured to start collecting patient information from the one or more sensors 8013. For example, this could include forehead temperature readings, heart rate readings, breathing waveforms etc.

[0553] This information is then compared against a pre-defined set of rules for control. For example, this may include detecting whether:

• The patient is awake, and whether the forehead temperature is above a predefined threshold, within a predefined range, or below a predefined threshold. • The patient is asleep, and whether the forehead cooling system should be deactivated, activated in a low-power state, or configured to target a predefined sleep temperature range.

[0554] Should any of the predefined rule criteria be met, the control system is configured to perform an action accordingly. For example, controlling the forehead cooling system in accordance with the pre-defined rules.

[0555] The pre-defined rules may be selected by the user from a list of preconfigured settings, for example a setting may be provided to keep the cooling active during the night, and an alternative setting may be provided for disabling the cooling once sleep is detected.

[0556] In other examples the pre-defined rules may be automatically adjusted over time. For example, if better quality sleep is detected under certain conditions (for example by monitoring breathing, heart rate, temperature and/or EEG data) then those conditions may be automatically learnt and repeated on subsequent nights. Conversely if poor sleep is detected, the forehead cooling system may be configured to activate such as by cooling the forehead to better regulate the patient’s sleep.

[0557] In some examples the pre-defined rules may be automatically adjusted for changes in the environment, such as the ambient temperature or noise levels in the environment. For example, on a night where the ambient temperature measures 27 degrees Celsius, the system may be configured to target a cooling temperature of 15 degrees, and a sleeping temperature of between 20 and 25 degrees. On a night where the ambient temperature measures 22 degrees, the system may be configured to target a cooling temperature of 15 degrees, and a sleeping temperature of between 18 and 22 degrees.

[0558] In another example, the target temperature profile may vary through the night, for example to match detected sleep stages of the patient. This can result in any suitable target temperatures and ramp settings as required.

5.8.6.4 User Control and Feeback

[0559] Fig. 24 shows one example of a personal computing device 9040 such as smartphone. The computing device 9040 may be configured to allow the patient to monitor and or control their preferred sleeping profile, for example by adjusting the predefined rules described herein. In in some examples this control functionality may instead be provided by a user interface on an RPT device 4000. [0560] In the illustrated example the computing device 9040 is configured to present the patient/user with a list of configurable settings which may be adjusted as necessary to thereby adjust the pre-defined rules considered by the cooling systems described herein. For example the user may be able to set target sleeping hours, sleeping temperatures, configure automatic detection of sleep onset, enable waking alarms, including auditory and foreheat heating options, configure whether cooling is desired during sleep, whether white noise should be provided to assist with sleep and whether the settings should auto adapt during use. The foregoing is intended to be a non-exhaustive list, and in some examples an advanced settings menu may be provided to allow the user to configure advanced parameters such as target temperature ranges, heating and cooling ramp settings etc.

[0561] In some examples the computing device 9040 may also provide the patient/user with detailed information about the quality, duration and efficacy of the forehead cooling systems 2000 described herein. For example, it may be advantageous for the systems described herein to capture sleep information for a user under a range of circumstances, such as with and without forehead cooling, with and without auditory stimulus, or respiratory pressure therapy etc, in order to determine the efficacy of any one or more of the settings provided.

[0562] Examples of the technology provide forehead cooling systems 2000 which are manually adjustable/controllable by the patient 1000. For example, with respect to Fig. 18A to 18C, the manual adjustment may be performed by rotating the central component 3456 with respect to the outer housing 3466. However, in other examples of the technology, cooling control may be performed using any one or more of: controlling the size of the conduit 15000, for example by closing or restricting a portion of the conduit, or diverting a portion of the flow through the conduit 15000, directing the flow through the conduit 15000, i.e., by redirecting airflow, by adjusting cooling or heating power (where thermoelectric coolers 5005 are used), controlling the rate or volume of flow, for example using the RPT device 4000 or flow generator, or a personal computing device in communication with the RPT device 4000 or flow generator.

[0563] In other examples the systems described herein may be provided with a control, such as a slider, knob, dial, proximity or touch sensitive interface through which the patient 1000 may control the device, such as increasing or decreasing a temperature set point, or adjusting flow. [0564] In some examples of the technology, the forehead cooling system 2000 may be controlled using one or more voice commands, such as “reduce temperature”, “stop cooling”, “increase flow” etc. For example, as described herein the forehead cooling system or any associated processors 9012 (such as a processor in the RPT device 4000, flow generator, or personal computer) may be connected to a sensor 8013 in the form of a microphone, configured to capture audio. This audio may then be processed by a processor 9012 to affect a control action, such as controlling the operation of the forehead cooling system 2000 in response to the instructions.

[0565] By allowing for the patient to directly control the forehead cooling systems 2000, the present technology may be more comfortable for the patient 1000 and increase compliance with any therapy the forehead cooling system 2000 provides. Where manual controls are provided, this may advantageously allow the patient to make adjustments easily for example while lying in bed, without needing to navigate complex menus, thereby further improving the ease of use of the systems described herein.

[0566] In some examples of the technology, manual control may act as an override to any pre-configured therapy settings. For example, these manual settings may replace any existing settings or alternatively, the system may be configured to return to the pre-configured settings once a change in sleep state is detected. For example, once sleep onset has occurred, or once the patient enters Nl, N2, N3, or REM sleep states the system may be configured to return to the pre-configured settings.

[0567] In some examples the override settings may only affect the settings which are active while the patient is awake.

[0568] Where the settings may be adjusted by the user, it may be advantageous for these settings to be persistent, such that they are maintained between sessions. [0569] Each of the controls may be used with any one or more of the forehead cooling systems described herein. For example, where thermoelectric coolers 5005 are used, these settings may be used to adjust the cooling set points, temperature ramp rates etc., in examples where a fluid flow is used (such as water or airflow) the controls may be configured to adjust the speed, volume, temperature, directionality or timing of the flow. 5.9 GLOSSARY

[0570] For the purposes of the present technology disclosure, in certain forms of the present technology, one or more of the following definitions may apply. In other forms of the present technology, alternative definitions may apply.

5.9.1 General

[0571] Air: In certain forms of the present technology, air may be taken to mean atmospheric air, and in other forms of the present technology air may be taken to mean some other combination of breathable gases, e.g. oxygen enriched air.

[0572] Ambient: In certain forms of the present technology, the term ambient will be taken to mean (i) external of the treatment system or patient, and (ii) immediately surrounding the treatment system or patient.

[0573] For example, ambient humidity with respect to a humidifier may be the humidity of air immediately surrounding the humidifier, e.g. the humidity in the room where a patient is sleeping. Such ambient humidity may be different to the humidity outside the room where a patient is sleeping.

[0574] In another example, ambient pressure may be the pressure immediately surrounding or external to the body.

[0575] In certain forms, ambient (e.g., acoustic) noise may be considered to be the background noise level in the room where a patient is located, other than for example, noise generated by an RPT device or emanating from a mask or patient interface. Ambient noise may be generated by sources outside the room.

[0576] Automatic Positive Airway Pressure (APAP) therapy: CPAP therapy in which the treatment pressure is automatically adjustable, e.g. from breath to breath, between minimum and maximum limits, depending on the presence or absence of indications of SDB events.

[0577] Continuous Positive Airway Pressure (CPAP) therapy: Respiratory pressure therapy in which the treatment pressure is approximately constant through a respiratory cycle of a patient. In some forms, the pressure at the entrance to the airways will be slightly higher during exhalation, and slightly lower during inhalation. In some forms, the pressure will vary between different respiratory cycles of the patient, for example, being increased in response to detection of indications of partial upper airway obstruction, and decreased in the absence of indications of partial upper airway obstruction. [0578] Flow rate-. The volume (or mass) of air delivered per unit time. Flow rate may refer to an instantaneous quantity. In some cases, a reference to flow rate will be a reference to a scalar quantity, namely a quantity having magnitude only. In other cases, a reference to flow rate will be a reference to a vector quantity, namely a quantity having both magnitude and direction. Flow rate may be given the symbol Q. ‘Flow rate’ is sometimes shortened to simply ‘flow’ or ‘airflow’.

[0579] In the example of patient respiration, a flow rate may be nominally positive for the inspiratory portion of a breathing cycle of a patient, and hence negative for the expiratory portion of the breathing cycle of a patient. Device flow rate, Qd, is the flow rate of air leaving the RPT device. Total flow rate, Qt, is the flow rate of air and any supplementary gas reaching the patient interface via the air circuit. Vent flow rate, Qv, is the flow rate of air leaving a vent to allow washout of exhaled gases. Leak flow rate, QI, is the flow rate of leak from a patient interface system or elsewhere. Respiratory flow rate, Qr, is the flow rate of air that is received into the patient's respiratory system.

[0580] Flow therapy. Respiratory therapy comprising the delivery of a flow of air to an entrance to the airways at a controlled flow rate referred to as the treatment flow rate that is typically positive throughout the patient’s breathing cycle.

[0581] Humidifier. The word humidifier will be taken to mean a humidifying apparatus constructed and arranged, or configured with a physical structure to be capable of providing a therapeutically beneficial amount of water (H2O) vapour to a flow of air to ameliorate a medical respiratory condition of a patient.

[0582] Leak. The word leak will be taken to be an unintended flow of air. In one example, leak may occur as the result of an incomplete seal between a mask and a patient's face. In another example leak may occur in a swivel elbow to the ambient. [0583] Noise, conducted (acoustic)-. Conducted noise in the present document refers to noise which is carried to the patient by the pneumatic path, such as the air circuit and the patient interface as well as the air therein. In one form, conducted noise may be quantified by measuring sound pressure levels at the end of an air circuit.

[0584] Noise, radiated (acoustic): Radiated noise in the present document refers to noise which is carried to the patient by the ambient air. In one form, radiated noise may be quantified by measuring sound power/pressure levels of the object in question according to ISO 3744. [0585] Noise, vent (acoustic): Vent noise in the present document refers to noise which is generated by the flow of air through any vents such as vent holes of the patient interface.

[0586] Oxygen enriched air: Air with a concentration of oxygen greater than that of atmospheric air (21%), for example at least about 50% oxygen, at least about 60% oxygen, at least about 70% oxygen, at least about 80% oxygen, at least about 90% oxygen, at least about 95% oxygen, at least about 98% oxygen, or at least about 99% oxygen. “Oxygen enriched air” is sometimes shortened to “oxygen”.

[0587] Medical Oxygen: Medical oxygen is defined as oxygen enriched air with an oxygen concentration of 80% or greater.

[0588] Patient: A person, whether or not they are suffering from a respiratory condition.

[0589] Pressure: Force per unit area. Pressure may be expressed in a range of units, including cmHiO, g-f/cm² and hectopascal. 1 cmbhO is equal to 1 g-f/cm² and is approximately 0.98 hectopascal (1 hectopascal = 100 Pa = 100 N/m² = 1 millibar ~ 0.001 atm). In this specification, unless otherwise stated, pressure is given in units of cmHiO.

[0590] The pressure in the patient interface is given the symbol Pm, while the treatment pressure, which represents a target value to be achieved by the interface pressure Pm at the current instant of time, is given the symbol Pt.

[0591] Respiratory Pressure Therapy: The application of a supply of air to an entrance to the airways at a treatment pressure that is typically positive with respect to atmosphere.

[0592] Ventilator: A mechanical device that provides pressure support to a patient to perform some or all of the work of breathing.

5.9.1.1 Materials & their properties

[0593] Hardness: Refers to durometer or indentation hardness, which is a material property measured by indentation of an indentor (e.g., as measured in accordance with ASTM D2240).

• ‘Soft’ materials may include silicone or thermo-plastic elastomer (TPE), and may, e.g. readily deform under finger pressure.

• ‘Hard’ materials may include polycarbonate, polypropylene, and may not e.g. readily deform under finger pressure. [0594] Silicone or Silicone Elastomer: A synthetic rubber. In this specification, a reference to silicone is a reference to liquid silicone rubber (LSR) or a compression moulded silicone rubber (CMSR). One form of commercially available LSR is SILASTIC (included in the range of products sold under this trademark), manufactured by Dow Corning. Another manufacturer of LSR is Wacker. Unless otherwise specified to the contrary, an exemplary form of LSR has a Shore A (or Type A) indentation hardness in the range of about 35 to about 45 as measured using ASTM D2240.

[0595] Polycarbonate: a thermoplastic polymer of Bisphenol-A Carbonate.

5.9.1.2 Mechanics

[0596] Axes: a. Neutral axis: An axis in the cross-section of a beam or plate along which there are no longitudinal stresses or strains. b. Longitudinal axis: An axis extending along the length of a shape. The axis generally passes through a center of the shape. c. Circumferential axis: An axis oriented perpendicularly with respect to the longitudinal axis. The axis may be specifically present in pipes, tubes, cylinders, or similar shapes with a circular and/or elliptical cross section.

[0597] Deformation: The process where the original geometry of a member changes when subjected to forces, e.g. a force in a direction with respect to an axis. The process may include stretching or compressing, bending and, twisting.

[0598] Elasticity: The ability of a material to return to its original geometry after deformation.

[0599] Floppy structure or component: A structure or component that will change shape, e.g. bend, when caused to support its own weight, within a relatively short period of time such as 1 second.

[0600] Resilience: Ability of a material to absorb energy when deformed elastically and to release the energy upon unloading.

[0601] Resilient: Will release substantially all of the energy when unloaded. Includes e.g. certain silicones, and thermoplastic elastomers.

[0602] Rigid structure or component: A structure or component that will not substantially change shape when subject to the loads typically encountered in use. An example of such a use may be setting up and maintaining a patient interface in sealing relationship with an entrance to a patient's airways, e.g. at a load of approximately 20 to 30 cmH20 pressure.

[0603] As an example, an I-beam may comprise a different bending stiffness (resistance to a bending load) in a first direction in comparison to a second, orthogonal direction. In another example, a structure or component may be floppy in a first direction and rigid in a second direction.

[0604] Stiffness (or rigidity) of a structure or component: The ability of the structure or component to resist deformation in response to an applied load. The load may be a force or a moment, e.g. compression, tension, bending or torsion. The structure or component may offer different resistances in different directions. The inverse of stiffness is flexibility.

[0605] Viscous: The ability of a material to resist flow.

[0606] Visco-elasticity: The ability of a material to display both elastic and viscous behaviour in deformation.

[0607] Yield: The situation when a material can no longer return back to its original geometry after deformation.

5.9.1.3 Structural Elements

[0608] Compression member: A structural element that resists compression forces.

[0609] Elbow: An elbow is an example of a structure that directs an axis of flow of air travelling therethrough to change direction through an angle. In one form, the angle may be approximately 90 degrees. In another form, the angle may be more, or less than 90 degrees. The elbow may have an approximately circular cross-section. In another form the elbow may have an oval or a rectangular cross-section. In certain forms an elbow may be rotatable with respect to a mating component, e.g. about 360 degrees. In certain forms an elbow may be removable from a mating component, e.g. via a snap connection. In certain forms, an elbow may be assembled to a mating component via a one-time snap during manufacture, but not removable by a patient. [0610] Frame: Frame will be taken to mean a mask structure that bears the load of tension between two or more points of connection with a headgear. A mask frame may be a non-airtight load bearing structure in the mask. However, some forms of mask frame may also be air-tight. [0611] Membrane: Membrane will be taken to mean a typically thin element that has, preferably, substantially no resistance to bending, but has resistance to being stretched.

[0612] Tie (noun): A structure designed to resist tension.

[0613] Thin structures: a. Beams, i. A beam may be relatively long in one dimension compared to the other two dimensions such that the smaller dimensions are comparatively thin compared to the long dimension b. Membranes, i. Relatively long in two dimensions, with one thin dimension. Readily deforms in response to bending forces. Resists being stretched, (might also resist compression). c. Plates & Shells i. These may be relatively long in two directions, with one thin dimension. They may have bending, tensile, and/or compressive stiffness.

[0614] Thick structures: Solids

[0615] Seal: May be a noun form ("a seal") which refers to a structure, or a verb form (“to seal”) which refers to the effect. Two elements may be constructed and/or arranged to ‘seal’ or to effect ‘sealing’ therebetween without requiring a separate ‘seal’ element per se.

[0616] Shell: A shell will be taken to mean a curved, relatively thin structure having bending, tensile and compressive stiffness. For example, a curved structural wall of a mask may be a shell. In some forms, a shell may be faceted. In some forms a shell may be airtight. In some forms a shell may not be airtight.

[0617] Stiffener: A stiffener will be taken to mean a structural component designed to increase the bending resistance of another component in at least one direction.

[0618] Strut: A strut will be taken to be a structural component designed to increase the compression resistance of another component in at least one direction. [0619] Swivel (noun): A subassembly of components configured to rotate about a common axis, preferably independently, preferably under low torque. In one form, the swivel may be constructed to rotate through an angle of at least 360 degrees. In another form, the swivel may be constructed to rotate through an angle less than 360 degrees. When used in the context of an air delivery conduit, the sub-assembly of components preferably comprises a matched pair of cylindrical conduits. There may be little or no leak flow of air from the swivel in use.

5.9.2 Anatomy

5.9.2.1 Anatomy of the face

[0620] Ala: the external outer wall or "wing" of each nostril (plural: alar)

[0621] Alar angle: An angle formed between the ala of each nostril.

[0622] Alare: The most lateral point on the nasal ala.

[0623] Alar curvature (or alar crest) point: The most posterior point in the curved base line of each ala, found in the crease formed by the union of the ala with the cheek.

[0624] Auricle: The whole external visible part of the ear.

[0625] (nose) Bony framework: The bony framework of the nose comprises the nasal bones, the frontal process of the maxillae and the nasal part of the frontal bone. [0626] (nose) Cartilaginous framework: The cartilaginous framework of the nose comprises the septal, lateral, major and minor cartilages.

[0627] Columella: the strip of skin that separates the nares and which runs from the pronasale to the upper lip.

[0628] Columella angle: The angle between the line drawn through the midpoint of the nostril aperture and a line drawn perpendicular to the Frankfort horizontal while intersecting subnasale.

[0629] Frankfort horizontal plane: A line extending from the most inferior point of the orbital margin to the left tragion. The tragion is the deepest point in the notch superior to the tragus of the auricle.

[0630] Glabella: Located on the soft tissue, the most prominent point in the midsagittal plane of the forehead.

[0631] Lateral nasal cartilage: A generally triangular plate of cartilage. Its superior margin is attached to the nasal bone and frontal process of the maxilla, and its inferior margin is connected to the greater alar cartilage.

[0632] Lip, lower (labrale inferius): The lip extending between the subnasale and the mouth. [0633] Lip, upper (labrale superius): The lip extending between the mouth and the supramenton.

[0634] Greater alar cartilage: A plate of cartilage lying below the lateral nasal cartilage. It is curved around the anterior part of the naris. Its posterior end is connected to the frontal process of the maxilla by a tough fibrous membrane containing three or four minor cartilages of the ala.

[0635] Nares (Nostrils): Approximately ellipsoidal apertures forming the entrance to the nasal cavity. The singular form of nares is naris (nostril). The nares are separated by the nasal septum.

[0636] Naso-labial sulcus or Naso-labial fold: The skin fold or groove that runs from each side of the nose to the comers of the mouth, separating the cheeks from the upper lip.

[0637] Naso-labial angle: The angle between the columella and the upper lip, while intersecting subnasale.

[0638] Otobasion inferior: The lowest point of attachment of the auricle to the skin of the face.

[0639] Otobasion superior: The highest point of attachment of the auricle to the skin of the face.

[0640] Pronasale: the most protruded point or tip of the nose, which can be identified in lateral view of the rest of the portion of the head.

[0641] Philtrum: the midline groove that runs from lower border of the nasal septum to the top of the lip in the upper lip region.

[0642] Pogonion: Located on the soft tissue, the most anterior midpoint of the chin.

[0643] Ridge (nasal): The nasal ridge is the midline prominence of the nose, extending from the Sellion to the Pronasale.

[0644] Sagittal plane: A vertical plane that passes from anterior (front) to posterior (rear). The midsagittal plane is a sagittal plane that divides the body into right and left halves.

[0645] Sellion: Located on the soft tissue, the most concave point overlying the area of the frontonasal suture.

[0646] Septal cartilage (nasal): The nasal septal cartilage forms part of the septum and divides the front part of the nasal cavity. [0647] Subalare: The point at the lower margin of the alar base, where the alar base joins with the skin of the superior (upper) lip.

[0648] Subnasal point: Located on the soft tissue, the point at which the columella merges with the upper lip in the midsagittal plane.

[0649] Supramenton: The point of greatest concavity in the midline of the lower lip between labrale inferius and soft tissue pogonion

[0650] Anatomy of the skull

[0651] Frontal bone: The frontal bone includes a large vertical portion, the squama frontalis, corresponding to the region known as the forehead.

[0652] Mandible: The mandible forms the lower jaw. The mental protuberance is the bony protuberance of the jaw that forms the chin.

[0653] Maxilla: The maxilla forms the upper jaw and is located above the mandible and below the orbits. The frontal process of the maxilla projects upwards by the side of the nose, and forms part of its lateral boundary.

[0654] Nasal bones: The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, the "bridge" of the nose.

[0655] Nasion: The intersection of the frontal bone and the two nasal bones, a depressed area directly between the eyes and superior to the bridge of the nose.

[0656] Occipital bone: The occipital bone is situated at the back and lower part of the cranium. It includes an oval aperture, the foramen magnum, through which the cranial cavity communicates with the vertebral canal. The curved plate behind the foramen magnum is the squama occipitalis.

[0657] Orbit: The bony cavity in the skull to contain the eyeball.

[0658] Parietal bones: The parietal bones are the bones that, when joined together, form the roof and sides of the cranium.

[0659] Temporal bones: The temporal bones are situated on the bases and sides of the skull, and support that part of the face known as the temple.

[0660] Zygomatic bones: The face includes two zygomatic bones, located in the upper and lateral parts of the face and forming the prominence of the cheek.

5.9.2.2 Anatomy of the respiratory system

[0661] Diaphragm: A sheet of muscle that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity, containing the heart, lungs and ribs, from the abdominal cavity. As the diaphragm contracts the volume of the thoracic cavity increases and air is drawn into the lungs.

[0662] Larynx: The larynx, or voice box houses the vocal folds and connects the inferior part of the pharynx (hypopharynx) with the trachea.

[0663] Lungs: The organs of respiration in humans. The conducting zone of the lungs contains the trachea, the bronchi, the bronchioles, and the terminal bronchioles. The respiratory zone contains the respiratory bronchioles, the alveolar ducts, and the alveoli.

[0664] Nasal cavity: The nasal cavity (or nasal fossa) is a large air filled space above and behind the nose in the middle of the face. The nasal cavity is divided in two by a vertical fin called the nasal septum. On the sides of the nasal cavity are three horizontal outgrowths called nasal conchae (singular "concha") or turbinates. To the front of the nasal cavity is the nose, while the back blends, via the choanae, into the nasopharynx.

[0665] Pharynx: The part of the throat situated immediately inferior to (below) the nasal cavity, and superior to the oesophagus and larynx. The pharynx is conventionally divided into three sections: the nasopharynx (epipharynx) (the nasal part of the pharynx), the oropharynx (mesopharynx) (the oral part of the pharynx), and the laryngopharynx (hypopharynx).

5.9.3 Patient interface

[0666] Anti-asphyxia valve (AAV): The component or sub-assembly of a mask system that, by opening to atmosphere in a failsafe manner, reduces the risk of excessive CO2 rebreathing by a patient.

[0667] Headgear: Headgear will be taken to mean a form of positioning and stabilising structure designed to hold a device, e.g., a mask, on a head.

[0668] Plenum chamber: a mask plenum chamber will be taken to mean a portion of a patient interface having walls at least partially enclosing a volume of space, the volume having air therein pressurised above atmospheric pressure in use. A shell may form part of the walls of a mask plenum chamber.

[0669] Seal: May be a noun form ("a seal") which refers to a structure, or a verb form (“to seal”) which refers to the effect. Two elements may be constructed and/or arranged to ‘seal’ or to effect ‘sealing’ therebetween without requiring a separate ‘seal’ element per se. [0670] Vent: (noun): A structure that allows a flow of air from an interior of the mask, or conduit, to ambient air for clinically effective washout of exhaled gases. For example, a clinically effective washout may involve a flow rate of about 10 litres per minute to about 100 litres per minute, depending on the mask design and treatment pressure.

5.10 OTHER REMARKS

[0671] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in Patent Office patent files or records, but otherwise reserves all copyright rights whatsoever.

[0672] Unless the context clearly dictates otherwise and where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit, between the upper and lower limit of that range, and any other stated or intervening value in that stated range is encompassed within the technology. The upper and lower limits of these intervening ranges, which may be independently included in the intervening ranges, are also encompassed within the technology, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the technology.

[0673] Furthermore, where a value or values are stated herein as being implemented as part of the technology, it is understood that such values may be approximated, unless otherwise stated, and such values may be utilized to any suitable significant digit to the extent that a practical technical implementation may permit or require it.

[0674] Furthermore, “approximately”, “substantially”, “about”, or any similar term used herein means +/- 5-10% of the recited value.

[0675] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present technology, a limited number of the exemplary methods and materials are described herein. [0676] When a particular material is identified as being used to construct a component, obvious alternative materials with similar properties may be used as a substitute. Furthermore, unless specified to the contrary, any and all components herein described are understood to be capable of being manufactured and, as such, may be manufactured together or separately.

[0677] It must be noted that as used herein and in the appended claims, the singular forms "a", "an", and "the" include their plural equivalents, unless the context clearly dictates otherwise.

[0678] All publications mentioned herein are incorporated herein by reference in their entirety to disclose and describe the methods and/or materials which are the subject of those publications. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present technology is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates, which may need to be independently confirmed.

[0679] The terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. [0680] The subject headings used in the detailed description are included only for the ease of reference of the reader and should not be used to limit the subject matter found throughout the disclosure or the claims. The subject headings should not be used in construing the scope of the claims or the claim limitations.

[0681] Although the technology herein has been described with reference to particular examples, it is to be understood that these examples are merely illustrative of the principles and applications of the technology. In some instances, the terminology and symbols may imply specific details that are not required to practice the technology. For example, although the terms "first" and "second" may be used, unless otherwise specified, they are not intended to indicate any order but may be utilised to distinguish between distinct elements. Furthermore, although process steps in the methodologies may be described or illustrated in an order, such an ordering is not required. Those skilled in the art will recognize that such ordering may be modified and/or aspects thereof may be conducted concurrently or even synchronously.

[0682] It is therefore to be understood that numerous modifications may be made to the illustrative examples and that other arrangements may be devised without departing from the spirit and scope of the technology.

Claims

6 CLAIMS

1. A patient interface configured to deliver a flow of breathable gas to a patient for treatment of a respiratory disorder, the patient interface comprising: a plenum chamber pressurisable to a therapeutic pressure of at least 4 cmH20 above ambient air pressure throughout a patient’s respiratory cycle in use, the plenum chamber comprising: a seal-forming structure constructed and arranged to form a seal with a region of the patient’s face surrounding at least one entrance to the patient’s airways, a positioning and stabilising structure configured to maintain the sealforming structure in position on the patient’s face in use, and a forehead cooling system, configured to cool the forehead of the patient in use.

2. The patient interface as claimed in claim 1, wherein the forehead cooling system comprises a conduit configured to direct a flow of air onto the forehead of the patient in use.

3. The patient interface as claimed in claim 3, wherein the flow of air comprises at least a portion of the flow of breathable gas.

4. The patient interface as claimed in claim 2 or 3, wherein the conduit is connected to the plenum chamber, and is configured to direct the flow of air out of the plenum chamber, towards the forehead of the patient.

5. The patient interface as claimed in claim 2 or 3, wherein the conduit is connected to an air circuit configured to connect to a connection port on the patient interface.

6. The patient interface as claimed in claim 2 or 3, wherein the conduit is provided in the positioning and stabilising structure.

7. The patient interface as claimed in claim 6, wherein a first conduit is fluidly connected to a first side of the positioning and stabilising structure in a region superior to the eyes of the patient.

8. The patient interface as claimed in claim 6 or 7, further comprising a second conduit positioned on a second, opposing side of the positioning and stabilising structure in a region superior to the eyes of the patient.

9. The patient interface as claimed in claim 8, wherein the first conduit is fluidly connected to the second conduit by a semi permeable material configured to vent a flow of air onto the forehead of the patient.

10. The patient interface as claimed in claim 1, wherein the forehead cooling system is positioned in contact with the forehead of the patient in use.

11. The patient interface as claimed in claim 10, wherein the forehead cooling system comprises a fluid reservoir.

12. The patient interface as claimed in claim 11, wherein the fluid reservoir comprises any one or more of: water, oil, a gel, or sodium poly acrylate.

13. The patient interface as claimed in claim 11 or 12, further comprising a pump configured to cause a fluid flow within the fluid reservoir.

14. The patient interface as claimed in claim 10, wherein the forehead cooling system comprises a thermoelectric cooler.

15. The patient interface as claimed in any one of the preceding claims, wherein the forehead cooling system comprises a thermal interface material which is positioned in contact with the forehead of the patient in use.

16. The patient interface as claimed in any one of the preceding claims, wherein the forehead cooling system comprises a heatsink.

17. A method of controlling a forehead cooling system comprising the steps of:

A) monitoring the temperature of the forehead of a patient;

B) activating a forehead cooler if the temperature of the forehead is greater than a first predetermined threshold;

C) deactivating the forehead cooler if the temperature of the forehead is lesser than a second predetermined threshold.

18. The method as claimed in claim 17, wherein the forehead cooler comprises a thermoelectric cooler.

19. The method as claimed in claim 17 to 18, wherein the first predetermined threshold is between 20 and 30 degrees Celsius.

20. The method as claimed in any one of claims 17 to 19, wherein the first predetermined threshold is substantially equal to 25 degrees Celsius.

21. The method as claimed in claim 17 to 20, wherein the second predetermined threshold is between 15 and 20 degrees Celsius.

22. The method as claimed in any one of claims 17 to 21, wherein the second predetermined threshold is substantially equal to 18 degrees Celsius.

23. The method as claimed in any one of claims 17 to 22, wherein the forehead cooler may comprise a first active mode and a second active mode, wherein the first active mode provides a first rate of cooling, and the second active mode provides a second rate of cooling which is less than the first active mode.

24. The method as claimed in claim 23, wherein the forehead cooling system is configured to switch from the first active mode to the second active mode when the forehead temperature is less than a third predetermined threshold, and from the second active mode to the first active mode when the forehead temperature is above the third predetermined threshold.

25. The method as claimed in claim 24, wherein the third predetermined threshold is between 20 and 22 degrees.

26. The method as claimed in any one of claims 17 to 25, wherein the forehead cooling system is only active during a period of sleep onset, and is inactive when the patient is detected to be asleep.

27. The method as claimed in any one of claims 17 to 26, wherein the forehead cooling system is configured to increase the temperature of the patient’s forehead as part of a waking routine.