CN211927449U - a moisture capture device - Google Patents

Abstract

A moisture capture device constructed by disposing a filter and desiccant material within a single-use patient mouthpiece. The device may also include a perforated foil that distributes the flow of exhaled air through the desiccant material.

Description

a moisture capture device

technical field

The present disclosure relates to the field of diagnostic measurements of endogenous nitric oxide (NO) in exhaled breath, devices for performing such measurements, and in particular to moisture capture devices for preventing moisture accumulation in such devices.

Background technique

The discovery of endogenous NO in exhaled air and its use as a diagnostic marker of inflammation dates back to the early 1990s (see, eg, WO 93/05709; WO 95/02181). Today, the importance of endogenous NO is widely recognized, and exhaled NO concentration or exhaled nitric oxide (FeNO) can help identify allergy/eosinophilic inflammation, supporting the lack of other objective evidence Diagnosis of asthma.

(瑞典AEROCRINE AB)是第一个用于哮喘患者常规临床使用的定制NO 分析仪。该第一个基于化学发光检测一氧化氮的设备已经被NIOX

(瑞典 CIRCASSIAAB)和

(CIRCASSIA AB，瑞典)所采用，这两种设备均基于电化学检测。

(AEROCRINE AB, Sweden) is the first custom-made NO analyzer for routine clinical use in asthma patients. The first device to detect nitric oxide based on chemiluminescence has been developed by NIOX

(Swedish CIRCASSIAAB) and

(CIRCASSIA AB, Sweden), both devices are based on electrochemical detection.

In the summer of 1997, the European Respiratory Journal published guidelines for standardizing NO measurements (ERS Task Force Report 10: 1683-1693) to allow their rapid introduction into clinical practice. Shortly thereafter, the American Thoracic Society (ATS) published guidelines for the measurement of clinical NO (American Thoracic Society, American Lung Association Division of Medicine: Recommendations for standardized procedures for theonline and offline measurement of exhaled lower respiratory nitric oxide andnasal nitric oxide in adults and children (recommendations for standardized procedures for online and offline measurement of nitric oxide and nasal nitric oxide in the exhaled lower respiratory tract of adults and children, see Am J Respir CritCare Med, 1999;160:2104-2117) . These recommendations have been updated, and in 2018, the Global Initiative for Asthma (GINA) published a global strategy for asthma management and prevention (full text available at www.ginasthma.org). However, the patient is still required to exhale for a period of time (at least 10 seconds) and exhale at a relatively constant flow, preferably at a flow of 50ml/s±5ml/s.

Endogenous NO is present in exhaled air in trace amounts, as low as 25 ppb (parts per billion) or less. Values between 25ppb and 50ppb should be interpreted with caution and with reference to the clinical situation, whereas values above 50ppb indicate eosinophilic inflammation or asthma.

Maintaining accurate expiratory flow into the device is critical to maintaining the accuracy of FeNO measurements. For this reason, most diagnostic devices for measuring FeNO have built-in pressure sensors. These pressure sensors measure the flow rate of the patient's exhalation, and the patient receives feedback that helps maintain the expiratory flow within the desired interval (50ml/s±5ml/s). However, it takes some practice to perform proper exhalation in the device. While some patients were already managed on the first or second attempt, others required repeated attempts to achieve successful measurements.

Exhaled breath contains water vapor. The average amount of water vapor in 10 seconds of exhalation at 24°C, 60% relative humidity (RH) was 448 μg. If a patient has difficulty exhaling properly, the same patient will repeatedly exhale moist breath into the device for a short period of time, which can cause moisture to build up in the device.

In some clinical settings, the frequency of use is very high. There is anecdotal evidence that as many as 80 patients in a day use some devices that measure exhaled NO. Also, as these devices are used in clinics around the world, some devices will inevitably be used in humid climates, such as southern and eastern China, parts of the southern United States, parts of Australia, India, Brazil, etc. However, moisture can be problematic in cooler climates. Since exhaled breath always contains moisture, it condenses when it comes in contact with cold surfaces.

These factors, alone and in combination, can lead to the accumulation of moisture in the equipment. This is a problem because once the accumulated moisture in the device reaches a certain level, the moisture starts to condense and form droplets. Water droplets have the potential to block the tube leading to the pressure sensor used to measure the flow rate. If water enters the pressure sensor, it can damage equipment parts.

Currently, some devices use algorithms to estimate the amount of moisture in the device and force the device to shut down when the amount of moisture becomes too high to allow it to dry. When the device is used with high frequency, especially in humid climates, such algorithms limit the number of measurements that can be performed before the device shuts down. This is unsatisfactory and requires preventing moisture from entering the device.

At the same time, the sample arriving at the electrochemical sensor should not dry out to such an extent that it affects the sensitivity of the sensor. Electrochemical sensors used to detect nitric oxide typically have some cross-sensitivity to _CO , which increases with decreasing moisture in the sample. In fact, some sensors require at least 20% RH to function properly.

There are known solutions for trapping moisture in exhaled breath, for example by directing the exhaled breath over a surface that is cooler than the exhaled breath, thereby causing moisture to condense on the surface. Examples include the device disclosed in WO 2004/058125 entitled "Disposable hand-held device for collection of exhaled breath condensate (disposable hand-held device for collection of exhaled breath condensate)" and the device entitled "Exhaled breath condensate collection device and kit of The device shown in WO 2017/153755 of parts for here (exhaled breath condensate collection device and kit of parts). These are valid in applications where the analysis of the coagulum itself is of interest, since the coagulum contains different substances that can be used as diagnostic markers. However, when the analyte is in the gas phase, the condensate needs to be handled and must be handled safely considering that the condensate can contain infectious substances such as viruses and bacteria and thus constitute a biohazard.

SUMMARY OF THE INVENTION

The present disclosure provides a new, practical and surprisingly effective solution to the above-mentioned problems. According to a first aspect, the present invention provides a moisture capture device suitable for use with an apparatus for diagnostic measurement of nitric oxide (NO) in exhaled breath, the apparatus comprising a handpiece for receiving exhaled breath, from The handpiece enters the channel of the device, a flow sensor and/or pressure sensor for measuring the flow and/or pressure of the exhaled breath in the channel, and generating a nitric oxide concentration corresponding to the exhaled breath A signal-detectable sensor or sensing element of Between the mouthpiece and the channel, the mouthpiece is adapted to be attached to the handpiece such that filter material and desiccant are located adjacent the handpiece.

According to an embodiment of the above aspect, the desiccant material is selected from molecular sieves, bentonite, silica beads, silica fines or particles, and combinations thereof.

According to another embodiment freely combined with the above-mentioned embodiments, the particulate filter material is selected from cellulose, cotton and glass fibers, or a combination thereof.

According to yet another embodiment freely combined with the above embodiments, the particulate filter material encapsulates the desiccant, thereby forming a composite filter pad.

According to another embodiment freely combined with the above-described embodiments, the moisture capture device comprises a perforated foil on at least one side of the filter and the desiccant, the perforations evenly distributing the breathing flow through the filter and the desiccant .

According to another embodiment freely combined with the above-mentioned embodiments, the moisture capture device has perforated foils on both sides, the perforations being arranged radially in the foil on one side and in the foil on the opposite side Placed in the middle of the film.

According to another embodiment freely combined with the above-mentioned embodiments, the foil is made of aluminium or plastic, preferably aluminium.

According to another embodiment freely combined with the above-described embodiments, the mouthpiece/moisture capture device is a single-use item intended for use by one patient and disposed of after use.

Description of drawings

The invention will be described in more detail in the following description, non-limiting examples and claims with reference to the accompanying drawings, wherein:

)的示例的照片，该装置包括主体1、手柄2、将所述手柄连接到主体的管3，以及患者咬嘴4。Figure 1 shows a device for diagnostic measurement of NO (here NIOX of CIRCASSIA AB, Sweden

), the device includes a body 1 , a handle 2 , a tube 3 connecting the handle to the body, and a patient mouthpiece 4 .

Figures 2(a) and 2(b) show an example of a patient mouthpiece 4 in two perspective views, wherein (a) shows the opening 5 into which the patient closes his/her lips and exhales. In a second view (b) it is shown how a volume or space 6 is formed under the mouthpiece suitable for holding the patient filter and desiccant material between the mouthpiece and the handle.

Figure 3 schematically shows a cross-section of a filter bag 13 containing a desiccant 16 in particulate or granular form.

Figure 4 schematically shows an exploded view of the moisture capture device 10 in accordance with aspects of the present invention, wherein the filter bag 13 is surrounded by two perforated foils 11 and 14, wherein the perforation 12 surrounds the perimeter of one foil and the perforation 15 is located at Another foil near the center. The perforations are not drawn to scale and the exact number, size and location of the perforations may vary.

5 shows a cross-section of the moisture capture device 10 with the flow path indicated by the white arrows, entering through the peripheral perforations 12 of the foil 11 , through the filter material 13 and desiccant 16 , and through the central perforations of the foil 14 15 to leave.

Figure 6 schematically illustrates the accumulation of moisture during use of a test setup simulating the use of the device for NO diagnostic measurements. The dashed line on the left and the dashed line on the right show the moisture accumulation at 85% RH and 60% RH, respectively. At higher humidity, the accumulated moisture reached a preset limit after three successful and one unsuccessful exhalations.

Figure 7 is a graph showing weight gain for different desiccant arrangements normalized for 360 uses. The two uppermost curves correspond to 19g and 14.3g of desiccant, and the three lower curves correspond to 1g, 2.7g and 2.8g of desiccant. The results showed that while high amounts of desiccant exhibited the greatest and longest-lasting weight gain, small amounts of desiccant worked well.

Detailed ways

Before describing the present invention, it is to be understood that the terminology employed herein is for the purpose of describing particular embodiments only and not of limitation, since the scope of the present invention is limited only by the appended claims and their equivalents.

It must be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

The term "mouthpiece" is used herein to describe the physical interface between a patient and a device for measuring endogenous NO in exhaled breath. When performing the test, the patient exhales into the mouthpiece. The mouthpiece is intended for single use and is discarded when the patient has successfully exhaled and FeNO values have been obtained.

According to a first aspect, the present disclosure provides a moisture capture device suitable for use with an apparatus for diagnostic measurement of nitric oxide (NO) in exhaled breath, the device comprising a mouthpiece for receiving exhaled breath, from which a mouthpiece leading to a channel of the device, a flow sensor and/or a pressure sensor to measure the flow and/or pressure of the exhaled breath in the channel, and generating a detectable signal corresponding to the concentration of nitric oxide in the exhaled breath A sensor or sensing element of Between the passages, the mouthpiece is adapted to be attached to the handpiece such that the filter material and desiccant are located adjacent the handpiece.

(德国达姆施塔特的默克制药公司(MERCK KGaA,Darmstadt,Germany))。According to an embodiment of the above aspect, the desiccant material is selected from the group consisting of molecular sieves, bentonite, silica gel beads, silica gel fine particles, and combinations thereof. Preferably, the desiccant material is a food grade silica gel material, which may be in the form of beads, granules or particulates. Many different qualities of silicone are available from many suppliers, such as from

(MERCK KGaA, Darmstadt, Germany).

According to another embodiment freely combined with the above-mentioned embodiments, the particulate filter material is selected from cellulose, cotton and glass fibers, or a combination thereof. Particulate filter materials are available from various suppliers, such as GVS Filtration Inc., Findlay, OH, USA.

According to yet another embodiment freely combined with the above embodiments, the particulate filter material encapsulates the desiccant, thereby forming a composite filter pad. The two circular sheets of filter material may be joined, eg glued or heat sealed, at the edges to form a pad that encapsulates the desiccant material. The filter material can also be bonded to the entire pad in a quilt-like manner, thereby minimizing movement of the desiccant material.

According to another embodiment freely combinable with the above-described embodiments, the moisture capture device comprises a perforated foil on at least one side, the perforations evenly distributing the breathing airflow through the filter.

According to another embodiment freely combined with the above-mentioned embodiments, the moisture capture device has perforated foils on both sides, the perforations being arranged circumferentially of the foil on one side and arranged in the foil on the opposite side Film Center.

According to another embodiment freely combined with the above-mentioned embodiments, the foil is made of aluminium or plastic, preferably aluminium. The holes may be punched or laser cut using techniques known to those skilled in the art. The exact size, number and location of the holes can be optimized to distribute the flow of exhaled air through the entire volume of desiccant material.

When the patient exhales into the handpiece through the mouthpiece, the exhaled breath is passed through the handpiece further into the device for the diagnostic measurement of nitric oxide, the exhalation phase is only 10 seconds. During exhalation, only a small fraction of the moisture in the exhaled air is absorbed by the desiccant. Instead, moisture condenses on the surface of the handpiece. However, since the moisture trap of the present invention is positioned near the handpiece, after expiration, this condensed moisture will be absorbed when the device measures and calculates the nitric oxide concentration in the exhaled breath. This phase may last 30 seconds or more after the patient has exhaled into the device through the mouthpiece and handpiece. The mouthpiece with the moisture trap was left in place until a successful exhalation was performed and the result (measured NO concentration) displayed. During this time, the moisture trap was surprisingly used to dry the inner surface of the handpiece, where the moisture had condensed during exhalation. This is a major advantage since condensation is a much more serious problem than moisture. When condensing on cooler surfaces in the handpiece, moisture forms droplets that travel in the flow channels/ducts and risk clogging and eventually damaging components such as flow/pressure sensors. So the moisture trap surprisingly has a dual function as a particle filter to protect the patient during inspiration and to "protect" the device as the patient exhales, and a desiccant sandwiched between the two layers of filter material to - To some extent - drying the exhaled air, but the important thing is the handpiece itself used to absorb and thus dry the exhaled breath.

One advantage of the solution disclosed herein is that the moisture capture device is easy to remove and replace, and also economical to manufacture. Several different needs are met by integrating particle filters/patient filters into moisture capture devices. The particle filter/patient filter forms a barrier between the device and the patient, preventing the spread of bacteria or viruses through the device. The filter material also has dual functions as a retainer or envelope for the filter and desiccant material. This makes it possible to replace current patient filters with a combined filter and desiccant assembly with little or no changes to the mouthpiece.

Example

Comparative Example. Dew Catcher

A mechanical dew trap was constructed by 3D printing and assembling parts to create a convoluted flow path and condensation chamber. The dew catcher is connected to the tube 3 between the handle 2 and the main body 1 of the device. Twenty dew traps were tested in clinical use and found to work as expected, ie collecting significant amounts of moisture in the condensation chamber. However, the experimental dew traps had to be opened, emptied and cleaned daily. Empty and Clean got very negative feedback from users. Due to potential biohazard risks, special care is required when emptying and disposing of collected moisture.

Example 1. Test voltage drop

In the experimental setup, 2 g of desiccant material was included in a "bag" of filter paper and tested in a standard mouthpiece to determine if the moisture capture device components blocked flow.

Table 1. Pressure drop of breathing handle

The results show that the moisture capture device can be integrated into existing mouthpieces without causing any significant pressure drop.

Example 2. Moisture Harvesting Capability

手柄和咬嘴连接到密封的气候室，产生大约35℃和97％RH的湿热空气，以模拟患者的呼吸。使用真空泵以3l/min的恒定速率抽吸空气，使用流量计和精细流量控制器手动调节流量。当离开手柄和咬嘴时，湿空气流直接进入冷却的凝结物收集室。根据当前的NIOX

用户手册，标准“呼吸”或设备“使用”的持续时间为10秒。计时器用于确保流动的持续时间等于每个单独测试所需的设备使用次数。将含有不同干燥剂量的不同水分捕获设备插入咬嘴中，必要时进行修改，并附接到手柄。在将水分捕获设备插入咬嘴中之前和之后，对水分捕获设备称重，并且将重量增加作为其有效性的量度。使用具有标准咬嘴(没有干燥剂)的手柄作为基线。所有测试均按照测试方法DEV-TM-058-R001进行。Construct the test setup as follows:

The handle and mouthpiece are connected to a sealed climate chamber that generates hot and humid air at approximately 35°C and 97% RH to simulate patient breathing. Air was drawn at a constant rate of 3 l/min using a vacuum pump, and the flow was adjusted manually using a flow meter and fine flow controller. As it leaves the handle and mouthpiece, the flow of moist air goes directly into the cooled condensate collection chamber. According to the current NIOX

User manual, standard "breathing" or device "use" duration is 10 seconds. A timer is used to ensure that the duration of the flow is equal to the number of equipment uses required for each individual test. Insert different moisture capture devices containing different desiccant doses into the mouthpiece, modify if necessary, and attach to the handle. The moisture capture device was weighed before and after it was inserted into the mouthpiece, and the weight gain was taken as a measure of its effectiveness. Use a handle with a standard mouthpiece (without desiccant) as a baseline. All tests were performed in accordance with Test Method DEV-TM-058-R001.

Silica gel ( _SiO2 ) was tested in the form of granules or beads (Clariant Co., Charlotte, NC, USA) with a bead size of 1.4 mm to 3.0 mm (Clariant Co., Charlotte, NC, USA) . The beads are bright orange when dry and dark blue when fully saturated with moisture.

Different amounts of silica gel are weighed and loaded directly into standard mouthpieces or packed in pads consisting of microfilters on both sides. The tested amounts of desiccant were 0.9g, 2.6g, 2.7g, 2.8g, 14.3g and 19.0g, which represent the maximum amount of desiccant currently designed to fill the mouthpiece. The unmodified mouthpiece and handle are used to create the baseline. With the desiccant in place, the 19.0g setting was tested for up to 780 uses or 7800 seconds of flow. This represents an extreme case and experiment when performed to see when the desiccant stops absorbing moisture from the air. The results showed that when 14.3 g was used, the desiccant did not turn completely blue after 180 uses (1800 seconds), and when 19.0 g was used, there was still residual desiccant capacity after 360 uses (3600 seconds). An example of the result is shown in Figure 7.

Example 3. Modification of flow path

In this example, a perforated cover or foil (item 11) as shown in Figure 4 was used to investigate whether the efficacy of the moisture capture device could be improved by changing the flow path of the exhaled breath through the bulk of the desiccant. As shown in Figure 4, the perforations are arranged along the perimeter of the foil. Experiments showed that the moisture capture device with 2.7 g of desiccant and perforated foil performed better than 2.8 g of desiccant without the foil. This is due to a more efficient flow path, which exposes the breathing flow to more surface area of the desiccant, thus absorbing more moisture.

Example 4. Amount of desiccant

The combined mouthpiece and patient filter are for one patient use only and are discarded after use. Since a maximum of 5 to 10 exhalations may be used, it was investigated whether the amount of desiccant could be minimized, assuming that the patient had great difficulty in performing proper exhalations. It can be seen that, corresponding to the first 100 seconds of 10 uses, the performance of the moisture capture device assembly containing only 0.9 g of desiccant is virtually equal to that of 19.0 g of desiccant.

In conclusion, experiments have shown that adding even a small amount of desiccant to a microfilter placed in the mouthpiece has a significant effect of removing moisture, thereby preventing moisture from entering the device, where it can run the risk of accumulating and possibly damaging parts of the device Or affect the accuracy of the measurement.

Example 5. Relative Humidity Measurement

A humidity sensor (Binder GmbH, Tuttlingen, Germany) was connected downstream of the experimental device described in Example 2 using a moisture capture device containing 2.6 g of desiccant. The humidity in the system was measured every 20 seconds for 6 minutes at a flow rate of 3 l/min. The results showed that the RH kept rising even though the desiccant unit was extracting moisture from the air upstream of the measurement point. The results show that the moisture capture device containing the desiccant does not over-dry the air reaching the electrochemical sensor. In fact, the use of a desiccant ensures that it helps to stabilize the RH in the air reaching the sensor.

Without further elaboration, it is believed that one skilled in the art can, using this description, including the examples, utilize the present invention to its fullest extent. Furthermore, although the present invention has been described herein in terms of its preferred embodiment, which constitutes the best mode currently known to the inventors, it should be understood that various changes and modifications will be apparent to those skilled in the art without departing from the scope of the invention as set forth in the appended claims.

Thus, while various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and not limitation, the true scope and spirit being indicated by the appended claims.

Claims (11)

1. A moisture capturing device adapted for use with an apparatus for diagnostic measurement of nitric oxide in exhaled breath, the apparatus comprising a handpiece for receiving exhaled breath, a passage leading from the handpiece to the device, a flow sensor and/or a pressure sensor for measuring the flow and/or pressure of the exhaled breath in the passage, and a sensor or sensing element that generates a detectable signal corresponding to the nitric oxide concentration in the exhaled breath, the moisture capturing device is characterized in that the moisture capturing device comprises a particulate filter material and a desiccant material, wherein the desiccant is disposed proximate the particulate filter material and within the mouthpiece or patient filter, or between the mouthpiece and the channel, the mouthpiece being adapted to be attached to the hand piece such that the filter material and the desiccant are located adjacent the hand piece.

2. The moisture capture device of claim 1, wherein the desiccant material is selected from the group consisting of silica gel beads, silica gel microparticles, and silica gel granules.

3. The moisture capture device of claim 1, wherein the particulate filter material is selected from cellulose, cotton, and glass fibers, or a combination thereof.

4. The moisture capture device of claim 1, wherein the device comprises a particulate filter material and a desiccant material, and wherein the particulate filter material encapsulates the desiccant, thereby forming a composite filter pad.

5. The moisture capture device of claim 1, wherein the moisture capture device comprises perforated foil on at least one side, the perforations arranged to evenly distribute a flow of breath through the filter.

6. The moisture capture device of claim 1, wherein the moisture capture device has perforated foil on both sides, the perforations being arranged circumferentially in the foil on one side and centrally in the foil on the opposite side.

7. The moisture capture device of claim 5 or 6, wherein the foil is made of plastic.

8. The moisture capture device of claim 5 or 6, wherein the foil is made of aluminum.

9. The moisture capture device of any of claims 1-6, wherein the mouthpiece/moisture capture device is a single use item.

10. The moisture capture device of claim 7, wherein the mouthpiece/moisture capture device is a single use item.

11. The moisture capture device of claim 8, wherein the mouthpiece/moisture capture device is a single use item.

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