JP2019527117A - Advanced respiratory monitors and systems - Google Patents

Abstract

Disclosed is a bioimpedance measurement system: a stabilized high frequency current generator is connected to a pad set electrode via a patient cable. Electrodes are connected to the adaptation circuit, which adjusts the resulting voltage signal and converts it to digital form. The firmware performs signal acquisition and relays data to the device.

Description

  This application also claims the priority of US Provisional Application No. 62 / 369,583 entitled “Advanced Respiration Monitor and System” filed on Aug. 1, 2016, which reference is , Its whole is incorporated.

  The present invention relates to devices and systems for monitoring respiration. In particular, the present invention also relates to devices and systems for monitoring respiration using impedance.

Physiological monitoring-history and evolution Patient monitoring is essential. The reason is that it provides a warning for patient deterioration, enables early intervention opportunities and greatly improves patient outcomes. For example, modern monitoring devices can detect abnormal heart rhythms, blood oxygen saturation, and body temperature abnormalities, alerting clinicians of deterioration that would otherwise be overlooked Is possible.

  The earliest record of patient monitoring reveals as early as 1550 BC that the ancient Egyptians knew the correlation between peripheral vascular pulse and heart beat. Three thousand years have passed before the next significant advance in terms of monitoring by Galileo using a pendulum to measure pulse rate. In 1887, Waller determined that he could passively record electrical activity across the chest by using electrodes and also correlated the signal to activity from the heart. It was. Waller's discovery paved the way for using electrical signals as a method for measuring physiological signals. However, it still took time for scientists to realize the benefits of monitoring physiological signals in a clinical environment.

  In 1925, MacKenzie highlighted the importance of continuous recording and monitoring of physiological signals, such as pulse rate and blood pressure. Specifically, he stressed that graphical representations of these signals are important in assessing patient conditions. In the 1960s, with the advent of computers, patient monitors improved with the addition of real-time graphical displays of multiple vital signs recorded simultaneously. An alarm was also incorporated into the monitor and was triggered when a signal such as pulse rate or blood pressure reached a certain threshold.

  The first patient monitor was used on the patient during surgery. Since it has been shown that patient outcomes improve, vital sign monitoring has spread to other areas of the hospital, such as intensive care units and emergency departments. For example, pulse oximetry was first widely used in the operating room as a noninvasive method for continuously measuring patient oxygenation. Pulse oximetry rapidly became the standard of care for general anesthetic administration and later spread to other parts of the hospital, including the recovery room and intensive care unit.

Increasing need for improved patient monitoring The number of critically ill patients serving the emergency department is growing at a high rate, and these patients require close monitoring. In 1-8% of patients in the emergency department, life-saving emergency procedures such as cardiovascular procedures or thorax and breathing procedures (mechanical ventilation, catheterization, arterial cannulation) are performed It has been estimated that it is demanding.

  Physiological scores, for example, Mortality Probability Model (MPM), Accurate Physiology and Chronic Health Education (APACHE), Implied Accurate Physiology (SAPS), showed that. Monitoring ill patients by using physiological scores and vital signs in the early stages of illness, even before organ failure or shock, improves outcomes. Close patient monitoring allows recognition of patient deterioration and application of appropriate therapy.

  However, current scoring methods do not accurately predict patient outcomes in approximately 15% of ICU patients, and it does not care for a large number of patients with acute respiratory failure in a respiratory intensive care unit, a hospital. Provided, but may be even worse for the patient in. In addition, currently monitored vital sign differences, such as blood oxygenation, occur late in the progression of respiratory or cardiovascular disorders. In many cases, the earliest sign of patient deterioration is a change in the patient's respiratory effort or breathing pattern.

  Respiration rate is recognized as a vital indicator of patient health and is used to assess patient status. However, the respiratory rate alone cannot show significant physiological changes, such as changes in respiratory volume. Metrics derived from continuous volumetric measurements have been shown to have great potential for determining patient status in a wide range of clinical applications. However, at present there are not enough systems that can accurately and conveniently determine the respiratory volume, which is the need for a non-invasive respiratory monitor that can trace changes in the respiratory volume. Motivate.

Disadvantages of current methods Currently, the patient's respiratory status is monitored by methods such as spirometry and end-tidal CO ₂ measurements. These methods are inconvenient to use and are often inaccurate. End-expiratory CO ₂ monitoring is useful in the assessment of patients intubated in various environments and during anesthesia, but it is inaccurate for unventilated patients. Spirometers and pneumotachometers are limited in their measurement and are highly dependent on patient effort and proper coaching by the clinician. Effective training and quality assurance are necessary for successful spirometry. However, these two requirements are not necessarily enforced in clinical practice such as when they are in research and pulmonary function studies. Quality assurance is therefore essential to prevent leading to wrong results.

  Spirometry is the most commonly performed lung function test. Spirometers and pneumotachometers can provide a direct measure of respiratory volume. It involves assessing the patient's breathing pattern by measuring the volume or flow of air as it enters and leaves the patient's body. Spirometry procedures and procedures are standardized by the American Thoracic Society (ATS) and the European Respiratory Society (ERS). Spirometry can provide important metrics for assessing respiratory health and for diagnosing respiratory lesions. The main drawback of mainstream spirometers is that they require the patient to breathe through the tube so that the patient's respiratory volume and / or flow rate can be measured. Breathing through the device introduces resistance to the flow of breathing and changes the patient's breathing pattern. It is therefore impossible to use these devices to accurately measure a patient's normal breathing. Breathing through the device requires a conscious and compliant patient. Also, in order to record the metrics proposed by ATS and ERS, patients must undergo burdensome breathing maneuvers, since most elderly, newborns can receive such tests. Exclude patients and COPD patients. Also, treatment outcomes are highly dependent on patient effort and coaching, as well as the skill and experience of the operator. ATS also recommends extensive training for health care professionals who practice spirometry. Also, many physicians do not have the skills necessary to accurately interpret the data obtained from lung function tests. According to the American Thoracic Society, the largest source of intra-subject variability is inadequate performance of the test. Therefore, most of the variability within and between patients with lung function tests is created by human error. Impedance-based respiratory monitoring fills an important gap because current spirometry cannot provide continuous measurements due to patient cooperation and requirements for breathing through the tube . Thus, near real-time information over long periods of time (as opposed to spirometry tests that last for less than a minute) in non-intubated patients that may show changes in breathing associated with provocation tests or therapeutic interventions There is a need for devices that provide

  In order to obtain acceptable spirometry measurements, as specified by the ATS standard, healthcare professionals must conduct extensive training and take a refresher course. One group showed that the amount of acceptable spirometry was significantly greater for those who conducted the training workshop (41% vs. 17%). Even with acceptable spirometry, the interpretation of the data by the attending physician was deemed incorrect by the pulmonologist with a 50% probability. However, it was noted that support from computer algorithms showed an improvement in interpreting spirograms when sufficient spirometry measurements were collected. Rigorous training is required for primary care clinics to obtain acceptable spirometry and make accurate interpretations. However, the resources to train a large number of people and enhance satisfactory quality assurance are irrational and inefficient. Even in a dedicated survey setting, the engineer's performance declines over time.

  In addition to human errors due to patients and health care providers, spirometry contains systematic errors that impair respiratory variability measurements. Useful measurements of respiratory pattern and variability have been shown to be exacerbated by airway fittings such as face masks or mouthpieces. Also, the discomfort and inconvenience associated with measurements with these devices prevent it from being used for routine measurements or as a monitor for long periods. Other techniques that are less invasive, such as thermistors or strain gauges, have been used to predict volume changes, but these methods provide poor information about respiratory volume. Respiratory belts have also been shown to be promising for measuring respiratory volume, but they are less accurate and have greater variability than measurements from impedance pneumography. The group has shown. Therefore, there is a need for a system that can measure volume over a long period of time with minimal patient and clinician interaction.

Lung function testing and pre- and post-operative care Pre-operative care identifies what patient characteristics can put patients at risk during surgery and minimizes those risks It concentrates on becoming. Medical history, smoking history, age, and other parameters specify the steps taken in preoperative care. Specifically, elderly patients and patients with pulmonary disease can be at risk for respiratory complications when placed under a ventilator for surgery. To clear these patients for surgery, pulmonary function tests such as spirometry are performed, which gives more information to determine if the patient can utilize the ventilator . A chest x-ray can also be taken. However, these tests cannot be repeated during surgery or in anesthetized patients or in patients who cannot or will not coordinate. The test may be uncomfortable in the post-surgical setting and may adversely affect patient recovery.

End-expiratory CO ₂ and patient monitoring End-expiratory CO ₂ is another useful metric for determining the lung status of a patient. The value is presented as a percentage or partial pressure and is measured continuously using a capnographic monitor, which can be coupled with other patient monitoring devices. These instruments produce a capnogram, which represents a waveform of CO ₂ concentration. Capnography compares carbon dioxide concentrations in exhaled air and arterial blood. The capnogram is then analyzed to diagnose respiratory problems, such as hyperventilation and hypoventilation. The end-expiratory CO ₂ trend is particularly useful for assessing ventilator performance and for identifying drug activity, technical problems associated with intubation, and airway obstructions. The American Academy of Anesthesiologists (ASA) should monitor end-tidal CO ₂ whenever an endotracheal tube or laryngeal mask is used, and for any treatment requiring general anesthesia. Commanded to be highly encouraged. Capnography has also proved more useful than pulse oximetry for monitoring patient ventilation. Unfortunately, it is generally inaccurate and difficult to achieve in an unventilated patient, and other complementary respiratory monitoring methods have great utility.

  The present invention overcomes the problems and disadvantages associated with current strategies and designs and provides new tools and methods for monitoring patients.

  The device of the present invention preferably provides continuous and non-invasive breathing that provides quantitative and graphical information regarding minute ventilation (MV), tidal volume (TV), and respiratory rate (RR). It is a monitor. In previous devices, the device requires the clinician to perform a single point calibration with a spirometer or ventilator for each patient before using the device. Performing this step allows accurate volume measurements for MV and TV. Alternatively, previous devices require collection of baseline data for normal breathing, with subsequent delivery and display of near real-time calculations of breathing (TV and MV) as a percentage of the individual's normal baseline . Despite numerous unsuccessful attempts to obtain accurate and clinically useful measurements with similar techniques, accurate measurements can be obtained without the need for patient-specific calibration. There wasn't. The device of the present invention eliminates the need for patient-specific calibration by the ventilator, or the need to obtain a normal baseline, has not previously been ventilated, or has normal breathing, Alternatively, it allows the use of the technique for patients who are unable to cooperate in collecting a normal baseline. This allows use of the device for patients who are in respiratory distress or after sedation or other therapy or palpation.

  Based on feedback from clinical studies accumulated over the past three years with extensive clinical data collection, the device in the present invention addresses the need for this single point calibration or normal baseline reference. Remove. Modifications to the device allow accurate respiratory volume data to be provided to the user without the need for single point calibration or the need for normal baseline reference.

  The device graphically displays lung volume over time and reports breathing rate, tidal volume, and minute ventilation without the need for single point calibration or normal baseline reference A non-invasive respiratory monitor.

The proposed invention is:
Bioimpedance measurement system: A stabilized high-frequency current generator is connected to a pad set (PadSet) electrode via a patient cable. The electrodes are connected to an adaptation circuit that adjusts the resulting voltage signal and converts it to digital form. Firmware performs signal acquisition and relays data to the computing device.
In one embodiment, the present invention utilizes a computing device that performs signal processing and calibration and launches a graphical user interface (GUI). The computing device takes user input from the touch screen through a virtual keyboard and mouse. The GUI is used to record patient data and is used to display respiratory traces and scalar values and trends for minute ventilation, tidal volume, and respiratory rate. In other embodiments, other computer systems or devices including a microprocessor may be used, such as an embedded or single board computer, a cellular phone, or any computing device.
• Single patient use pad set electrode: An electrode set to be placed on the torso. It delivers current and records impedance measurements. In the preferred embodiment, this is a printed circuit pad set with a single connector, which allows for easy and accurate installation.

  In one embodiment, the device is used by health care professionals in health care facilities, such as post-operative care and critical care rooms, to monitor breathing in adult (above 21) patients Is intended to be. In one embodiment, the device is used for pediatric or neonatal patients. In one embodiment, the device is used in a home or other outpatient setting. In one embodiment, the device is used in a fitness environment, a wellness environment, or an observation environment, where measurements will be valuable without input from a healthcare professional.

  In one embodiment, measurements from the proposed invention are used as an adjunct to other clinical information. In one embodiment, the measurements are utilized for decision support, either automated or directed to a health care professional, caregiver, or individual being measured. The

  One embodiment of the invention relates to a respiratory monitoring system. The system comprises a computing device and an electrode pad set configured to be coupled to a patient. The computing device comprises a processor, at least one graphical user interface (GUI) in communication with the processor, and at least one sensor input in communication with the processor. The electrode pad set can be coupled to the sensor input, receives electrical signals from the computing device, and detects bioimpedance signals through the patient's torso. The processor based on the detected bioimpedance signal without the need for both calibration of known values and baseline collected during normal ventilation, and without patient assistance, One or more of minute ventilation (MV), expected MV percentage, tidal ventilation (TV), expected TV percentage, respiratory rate (RR), and expected RR percentage Is determined in real time. The GUI is determined among minute ventilation (MV), expected MV percent, tidal ventilation (TV), expected TV percent, respiratory rate (RR), and expected RR percent. Output one or more in real time.

  In a preferred embodiment, the system provides at least one indication of hyperventilation, normal ventilation, and hypoventilation. Preferably, the system provides an indication of development of at least one hypoventilation, change in respiratory signal waveform, change in inspiratory expiration ratio, and inspiration plateau based on opioid-induced respiratory depression. Preferably, the computing device is configured to provide continuous measurement of ventilation within one minute after entering patient demographics into the device. The demographic is preferably at least one of patient height, weight, and gender. Preferably, the computing device provides continuous measurement of ventilation without the need for patient specific calibration to the ventilator or the need for a baseline when the patient is breathing normally. It is configured.

  In a preferred embodiment, the computing device is configured to provide continuous measurement of ventilation as soon as the electrodes are attached to the device and without entering demographic data. Preferably, patient cooperation and control over patient breathing is not required. Preferably, no device calibration is required for known ventilator, spirometer, and pneumotachometer readings. The computing device preferably further comprises an HR-RR cut-off filter. Preferably, the HR-RR cutoff filter filters the respiratory signal and the heart signal based on a predetermined heart rate cutoff point. In a preferred embodiment, the heart rate cutoff point is one of 30, 40, 50, or 60 beat per minute (bpm).

  Preferably, the heart rate cutoff point is based on at least one of patient demographics, percentage of MV or expected MV, and rapid superficial respiratory index. The heart rate cutoff point is preferably entered manually or updated automatically by the computing device. In a preferred embodiment, the HR-RR cut-off filter is a measure of the gain of the impedance signal, a scaling factor for the absolute value of the impedance trace displayed on the GUI, an indication of the decrease in tidal volume, a sedation level At least one of the following indications and a diagnosis of respiratory disease.

  Preferably, the system further comprises at least one audible or visual alarm. Preferably, the at least one audible or visual alarm is set based on at least one of a patient disease state, a physician assessment, a clinical or therapeutic environment, a physiological measurement, or an external reference. . Preferably, at least one audible or visual alarm is compatible.

  The expected MV is preferably calculated based on the patient's height, weight, and gender. Preferably, the expected MV calculation further comprises at least one of patient specific physiology, anatomy, morphology, or topology. In a preferred embodiment, the system is solid, unconscious, alert, dying, intubated with a ventilator, in respiratory distress, or It is configured for use with patients who are one of those after sedation. Preferably the system is non-invasive. The system preferably further comprises a patient cable coupling the electrode pad set to the computing device, the patient cable being configured to transmit high frequency current to the patient via the electrode pad set.

  Other embodiments and advantages of the invention are described in part in the description that follows, and in part can be apparent from the description, or can be learned from the practice of the invention.

1 is a front view of an embodiment of a device of the present invention. FIG. 6 is a rear view of an embodiment of the device of the present invention. FIG. 5 shows an embodiment of a patient cable. It is a figure which shows embodiment of an electrode pad set. FIG. 6 is a diagram showing an embodiment of a preferred installation of an electrode pad set on the trunk. FIG. 2 illustrates an embodiment of a graphical user interface (GUI). FIG. 2 illustrates an embodiment of a graphical user interface (GUI). FIG. 2 illustrates an embodiment of a graphical user interface (GUI). FIG. 2 illustrates an embodiment of a graphical user interface (GUI). FIG. 2 illustrates an embodiment of a graphical user interface (GUI).

  The proposed invention is a non-invasive respiratory monitor, which does not require calibration with ventilators, spirometers, and pneumotachometers, and does not require the acquisition of a normal baseline. A graphical representation of the volume of air and a report of minute ventilation, tidal volume, and respiratory rate. This allows the use of the technique for patients who have not previously been ventilated, have no normal breathing, or cannot cooperate in collecting a normal baseline.

In one embodiment, the proposed invention consists of:
• Bioimpedance measurement system: A stabilized high-frequency current generator is connected to the pad set electrode. The electrodes are connected to an adaptation circuit that adjusts the resulting voltage signal and converts it to digital form. Firmware performs signal acquisition and relays data to the processing device.
Processing device: A processing device (eg, tablet, smartphone, computer, dedicated device, microprocessor, or other computing device) performs signal processing and calibration and launches a graphical user interface (GUI). The processing device takes user input from the touch screen through a virtual keyboard and mouse. The GUI is used to record patient data and is used to display respiratory traces and scalar values and trends for minute ventilation, tidal volume, and respiratory rate.
• Single patient use pad set electrode: An electrode set to be placed on the torso. It delivers current and records impedance measurements.

  In one embodiment, the monitor preferably has a unit size of 12 inches (h) x 12 inches (w) x 6 inches (d) and a unit weight of 8 lbs, but the units are separate It is also possible to have a size of The length of the patient cable is approximately 8 feet, but the cable can be of other lengths. The length of the pad set can be adjusted to fit a wide range of patients. In one embodiment, data is collected and transmitted wirelessly to a device, such as a cell phone screen, smartwatch, pager, or other portable receiver.

In a preferred embodiment, the user interface is preferably a display with an LED backlight, a pointing device, and / or a capacitive touch screen. The device preferably has a measurement accuracy as follows:
Minute ventilation (MV)-better than 20% Tidal volume (TV)-better than 20% Respiration rate (RR)-better than 20% Or more preferably,
Minute ventilation (MV)-better than 15% Tidal volume (TV)-better than 15% Respiration rate (RR)-better than 5%, or 1 breath per minute.

  In one embodiment, the device preferably outputs a patient measurement current compliant with ANSI / AAMI 60601-1. In one embodiment, none of the device components need to be shipped sterilized. In one embodiment, the pad set component can be sterilized and autoclaved, or can be gas sterilized. The device itself is not intended for patient contact and is not intended for use inside a sterilization site. In one embodiment, the electrode pad set is intended to contact the skin for up to 24 hours. In one embodiment, the electrode pad set can be in contact with the skin for up to a week. In one embodiment, the pad set is preferably made from polyester (PE). There can be a foam donut above the pad set, which is in contact with the patient and is made of polyester. In a preferred embodiment, the pad set uses a biocompatible glycerin hydrogel for electrical integrity of the connection with the patient. In one embodiment, the operating temperature range of the monitor is 40-90 ° F., the operating humidity range is 20-80% (non-condensing), with a storage temperature range of −149 ° F. The storage humidity range is 20-80% (no condensation).

  In a preferred embodiment, the pad set has a preferred operating temperature range of 4-90 ° F, a preferred operating humidity range of 20-80% (non-condensing), a preferred storage temperature range of 14-122 ° F, And has a suitable storage humidity range of 20-80% (no condensation).

  Preferably, the exposed surfaces of the monitor and cable can be wiped with a disinfectant. The display screen can be cleaned with a commercial grade cleaning solution. Preferably, the system has suitable power requirements of 100-240V, 50 / 60Hz input voltage and frequency, and <600W power consumption.

  The device preferably has the following environment: ICU, procedural sedation, supervised anesthesia management, non-operating room anesthesia, perioperative environment, operating room, general hospital floor, clinic, long-term care facility, home, gym, It can be used in a rehabilitation center or any other environment where it will be desired to perform respiratory monitoring. The proposed invention reports low MV, which is the definition of hypoventilation (respiratory depression). Monitoring MVs according to the proposed invention helps to detect respiratory depression. The proposed invention provides an indication of disordered breathing.

  The MV measurement provided by the device preferably helps to detect and assess opioid-induced respiratory depression. Using the proposed invention to detect hypoventilation and / or hyperventilation earlier can generally help improve respiratory care and healthcare delivery. The device preferably reports high MV, which is the definition of hyperventilation and provides insight into respiratory failure, diffusion gradients, sepsis, and other conditions associated with increased work of breathing To do. The device preferably provides objective data about respiratory conditions that may improve patient safety. The device preferably alerts the clinician of changes in respiratory status either at the bedside or remotely. The device preferably provides additional breathing information in an unintubated patient, which can enhance patient safety.

  In one embodiment, the device preferably provides for minute volume, tidal volume, advanced respiratory parameters, general respiratory status, and changes in respiratory status for patients who have not previously had respiratory monitoring. Measure and display one or more of the quantitative assessments. In this embodiment, when monitoring begins, the patient can be anywhere on the spectrum of hypoventilation, normal ventilation, hyperventilation, or can show any of a variety of breathing patterns. Is possible. In a preferred embodiment, continuous measurement of ventilation is provided within one minute of entering patient demographics into the monitor. In one embodiment, the device preferably provides continuous monitoring of ventilation as soon as the electrodes are attached to the device, without the requirement of demographic data. In a preferred embodiment, the device preferably has sufficient accuracy and ease of use and involves only entering height, weight, and gender into the device, and the patient is normal Without a requirement for a baseline when breathing or a requirement for calibration with measurements from a ventilator, spirometer, or pneumotachometer, the device preferably allows the patient to face the following clinical scenario: Have severe respiratory distress, have obvious respiratory failure, have apnea episodes, have experienced respiratory arrest, have experienced cardiac arrest, have significant arrhythmia Have heart failure, have become hyperventilated from sepsis, have hyperventilation due to hypoxia from pulmonary embolism or other causes, When the light causes have hyperventilation or hypoventilation, has become one or more of the first time provides a device that may be used.

  In one embodiment, the device preferably reports low MV, where low MV is the definition of hypoventilation (respiratory depression, respiratory disorder). In one embodiment, the device preferably identifies patients who are experiencing or are at risk for opioid-induced respiratory depression. Surprisingly, in a preferred embodiment, the device preferably provides the patient's basal by quantifying the absolute value or change in MV after one or more doses of opioid administration. The use of the device is initiated after the opioid has been administered, and there is no hypoventilation, as it provides an indication of the correct opioid sensitivity and there is no need to collect or calibrate the baseline (Respiratory depression, respiratory disturbance) can be assessed and quantified. In a preferred embodiment, monitoring by the device is preferably initiated in a patient suspected of having a disordered breathing or suspected of taking an opioid overdose and is accurately monitored during evaluation and / or resuscitation. Data from the proposed invention is used by caregivers for patients who have a respiratory disorder or who are clinically assessed to have the potential for respiratory disorder (either hypoventilation or hyperventilation). Initiate treatment and observe the effect of one or more of stimulation, positioning, opioid or benzodiazepine reversal, oxygen administration, CPAP, BiPAP, furosemide, high-flow oxygen, or other respiratory therapy.

In preferred embodiments, the device preferably provides a method for risk stratification of patients without the need for calibration or the collection of baseline measurements (eg, the 80/40 method. 80/40. In the method, patients who have sustained MV <80% MV _PRED for more than 2 minutes prior to taking opioids are considered “at risk” and will take at least 2 minutes within 15 minutes following opioid use. Patients who have sustained MV <40% MV _PRED have “low MV” or are considered “unsafe”). The device preferably supports an 80/40 risk stratification method after the surgical procedure and is dangerous with respect to opioid-induced respiratory depression without the need for a baseline before sedation or the need for calibration to the ventilator. Helps detect patients in condition. Previously, this risk stratification may only occur after the patient has been calibrated before surgery with a spirometer, after a normal baseline collected, or after being calibrated during surgery by a ventilator. did it. The present invention allows stratification to be performed on any post-surgical patient, where the respiratory condition is modified by anesthetics, opioids, or sedatives and is often reduced. This embodiment allows for identification that the patient is at risk for respiratory depression in a post-surgical setting, which includes identifying patients at risk for respiratory depression at the general hospital floor. Preferably, information regarding the patient's respiratory status will be communicated to a central care station or to a phone carried by a nurse or other caregiver. In one embodiment, patient respiratory status and risk related information is communicated by a nurse call system. In one embodiment, the information is centralized by any wired or wireless connection for independent analysis or pairing with other physiological information, demographic information, and laboratory information. Relayed to. Preferably, the proposed invention is greater than 70% sensitivity, greater than 75% sensitivity, greater than 80% sensitivity, more preferably greater than 85% sensitivity, and most preferably 90% A sensitivity greater than 1 helps to identify patients at risk for opioid-induced respiratory depression. The proposed invention is more than 70% sensitivity, more than 75% sensitivity, more than 80% sensitivity, more than 85% sensitivity, more preferably more than 90% sensitivity, and most preferably Helps identify patients who will not develop opioid-induced respiratory depression with post-surgical accuracy of greater than 95% sensitivity.

  Surprisingly, in a preferred embodiment, the accuracy of the device is preferably the individual needs of the device relative to the known ventilator, spirometer and pneumotachometer readings, as well as the need for a patient specific baseline. It can be used without the need for calibration and without the need for patient cooperation. With this device, preferably patient cooperation or control over patient breathing is not required (either by the patient or by an external ventilator) to provide a measure of respiratory performance. This allows the monitor to be used in any patient condition (conscious, alert, dying, intubated ventilator, etc.).

In this embodiment, the device not only reports MV, TV, and RR, but also reports the expected percentage MV based on patient size. In a preferred embodiment, one or more patient demographics of height, weight, and gender are input into the device and the expected MV is such as ideal weight or body surface area, etc. Calculated based on the formula. The calculated MV _PRED is then used to convert the measured MVs to their expected percent ventilation (% MV _PRED ) based on the patient's breathing real-time signal, and A respiratory status indication is provided to the caregiver, which is corrected for patient size and gender, and allows the establishment of a protocol based on the percentage of normal ventilation.

  The device preferably identifies patients with MV <40% as being at increased risk for respiratory depression. The device preferably assists in measuring the effectiveness of airway maneuvers during procedural sedation for respiratory conditions without the need for previous calibration or baseline. The device preferably helps direct the need for airway manipulation during sedation for treatment. The device preferably helps to quantify the effects of sedatives and opioids on the respiratory condition during sedation on treatment. Surprisingly, the device is preferably capable of accurately reporting the minute volume, the expected percent minute volume, without the need for a pre-treatment baseline or individual calibration. is there. The device preferably helps to quantify the effect of the anesthetic on the respiratory condition during sedation, and the device implementation may be initiated following delivery of the sedative or anesthetic. Preferably, device measurements are more reliably available compared to capnographic measurements during procedural sedation / supervised anesthesia management / and non-operating room anesthesia. The device preferably assists in identifying respiratory depression for patients receiving PCA opioids. The device preferably assists in assessing respiratory status for patients receiving PCA opioids. The device preferably measures the effect of benzodiazepines on the respiratory condition. The device preferably measures the effect of opioids on the respiratory condition and is immediately initiated and improved in a quantitative manner for uncooperative patients in respiratory distress or apparent respiratory failure Or it can be used to report deterioration. The device is preferably capable of forming the basis of a personalized pain management protocol. In one embodiment, the device is preferably used to drive a drug overdose protocol and to evaluate the effectiveness of Narcan therapy in drug overdose, rapid additional administration, or intubation Can be used to determine the need.

  In one embodiment, the device preferably measures the effect of a neuromuscular blocking agent on the respiratory condition. In one embodiment, the device preferably measures the effect of an anesthetic on the respiratory condition. The device preferably provides an MV measurement, which is an indicator of respiratory depression earlier than SpO2. The proposed invention MV measurement has better sensitivity and reliability than capnometry when detecting respiratory depression. Device MV measurements have better sensitivity and reliability than capnometry when detecting changes in respiratory conditions. Device MV measurements have better sensitivity and specificity than respiratory rate in defining respiratory depression, hypoventilation, and respiratory impairment. In a preferred embodiment, the proposed invention provides respiratory suppression in approximately 80% of patients missed by respiratory rate measurements alone in multiple environments including hospital floors, PACUs, and endoscopy. Identify. The placement of the device's trunk electrodes preferably minimizes the occurrence of unpleasant alarms.

HR-RR cut-off filter During preprocessing of the impedance data in the cleared device, the default filter used for the separation of cardiac and respiratory signals was set at a rate of 40 bpm. In a small percentage of patients (eg, athletes), the heart signal may have a base frequency (heart rate) lower than 40 bpm. In other patients (eg, pediatric patients), the respiratory rate can be higher than 40. To improve performance in such patients, customized filtering is available in the proposed device to allow the device to better separate respiratory and cardiac signals. This customized filtering can be done as either an adaptable filter or filter bank containing filters with various HR / RR cut-off points (eg, 30, 40, 50, 60 bpm, etc., see FIG. 6E). Can be realized.

  In one embodiment, the RR / HR cutoff is continuous (eg, larger patients have a smaller cutoff) or (eg, adult vs. child, weight-based, height-based) Based on patient size as a step function (based on BSA). In one embodiment, the HR / RR cutoff is based on one of selection criteria, such as patient height and weight, and depending on actual measurements of either or both HR or RR. It has been refined. In one embodiment, the cutoff is based on HR and RR and is refined by patient size. In either case, the size-related HR and / or expected RR can be manually input from an external device or from a clinical assessment or into the device (eg, from BiPAP, ventilator, etc.). Or automatically imported from external measurements of HR or RR (eg, RR from BiPAP or ventilator, or HR from EKG or pulse oximeter), or HR is corrected by requiring simultaneous measurements from both the RVM and pulse oximeter, electrocardiogram, or pleth, or other evidence of pulse rate. In one embodiment, the HR is one or more of the frequency in the signal, the difference from the known RR frequency, the ratio to the RR frequency, and the difference in size of the impedance change due to HR vs RR. Determined using In one embodiment, the expected% MV or MV can be used to define the HR / RR cutoff in real time (eg, a higher% MVpred would result in a higher cutoff, If% MVpred is low, the cut-off will be lower).

  In one embodiment, the HR / RR cutoff can be adjusted based on the rapid superficial respiratory index (RSBI = RR / TV), and if RSBI is high, is the cutoff adjusted automatically? Or the device alerts the user to change the cutoff or to check RR or HR or both. The proposed device alerts the user to check and input the correct HR if the RR exceeds a predefined limit (eg,> 35 for adults,> 50 for pediatric patients, etc.) It is possible or the cut-off can be adjusted automatically. In one embodiment, the respiration detection algorithm is continuously updated with the ratio of HR to RR.

  When the device presents an impedance-based breath trace, or an interval over which the scaling (gain, conversion factor, or scaling factor) of this trace is calculated, preferably the cutoff point or HR / RR ratio, or Two combinations can be used to determine or automatically set the gain of the impedance signal. In one embodiment, the relative size of the cardiac signal (associated with the HR as identified by the filter) is compared to the relative size of the respiratory signal and displayed on the screen as impedance. It is possible to create a scaling factor / gain for the absolute value of the trace (y-axis). The relative size of the cardiac signal can be input or estimated based on stroke volume measurements by other means, or can be assumed to be 70 cc for an average adult, or BSA, BMI, Or it can be related to height, etc.

  Given a properly filtered heart signal, the change in the size of the HR signal vs. RR signal, or the relative size of the HR signal vs. RR signal, is preferably the overall tidal volume in the respiratory trace. Can also be used to trigger changes to a breath detection algorithm optimized for smaller volumes.

  The device can use HR / RR cutoff or ratio of inhalation duration to exhalation duration (I / E ratio) or a combination of the two to indicate the level of sedation or diagnosis of respiratory disease. is there. In one embodiment, the long plateau duration at the end of inspiration indicates opioid-induced sedation (see FIGS. 6A-C). In one embodiment, the plateau duration is used to adjust the HR / RR cutoff. In one embodiment, the duration from breath to breath corresponds to a breathing interval as defined from the end of expiration to the end of expiration, or the interval between the end of expiration and the beginning of inspiration. Yes.

  The device preferably uses input TV or MV measurements (in volume synchronization mode) in combination with measured or input HR and / or cardiac signals to better differentiate HR from HR It is possible to help adjust the HR / RR filter cutoff to In one embodiment, both TV and RR are input from a ventilator, BiPAP, spirometer, pneumometer, or another device. If MV is input from the ventilator, RR is input from the ventilator, and RR is different from ventilator RR, the HR / RR filter or respiration detection algorithm is adjusted.

  If the device reports RR as being higher than what is actually observed by clinical or other measurement techniques, this is when HR is below the HR / RR cutoff, or , Either just above but close to the cutoff, and when in the transition band (between the pass band and stop band). In such cases, the device can automatically select, prompt, or receive information with or without an external input of RR or HR, with a lower cut-off point Select the filter, shift the transition band away from the HR, effectively place the HR in the stop band of the newly selected filter, and improve the accuracy of the RR counting.

Expected MV
In existing devices, the expected MV (MV _PRED ) is calculated using a simple formula based on the patient's height, weight, and gender, which is used as a reference value and is relative to the world average. Provides a relative scale for comparison of respiratory performance and allows trending over time against known guidelines. In this device, MV _PRED can be further adjusted to take into account patient-specific physiology, anatomy, morphology, or topology. In one embodiment of the device, an athlete with a high BMI will have an elevated MV _PRED when compared to a deskwork obese patient with a similar BMI. In one embodiment, patients with chronic lung disease have a higher MV _PRED than healthier patients of the same height, weight, and gender due to the reduced ability of their lungs to exchange oxygen and CO2. Thus increasing their need for “baseline” breathing.

Alarm limits Current devices use predefined standard alarm limits based on expected MVs calculated according to patient size (height and weight). In one embodiment, instead of using standard alarm limits, the alarm limits are: patient disease status (thyroid, diabetes, COPD, etc.), physician assessment, clinical or treatment environment ( ICU, home, high pressure chamber, use of ventilator, use of BIPAP, use of CPAP, use of high flow oxygen, negative pressure ventilation, alternating ventilation, eg high frequency or oscillator, ECMO, etc., additional physiological measurements (BP HR, EtCO2, SpO2, fluid level, etc.) or external reference (CPAP, ventilator, PFT test, etc.). These adaptive alarm limits can be used to alert deteriorating patient conditions, but can also be used to track treatment improvements and / or benefits in connection with therapy / treatment. .

  The following examples illustrate embodiments of the present invention but should not be viewed as limiting the scope of the invention.

Example This Device Compared to an Existing Commercially Available Device This device is manufactured by Respiratory Motion, Inc. Compared to ExSpiron 1Xi marketed by (Waltham, MA). Also, the proposed invention is disclosed in nSpire Health, Inc. Compared to the Wright / Haloscale Respirometer marketed by (Longmont, CO). Because it is not possible to obtain simultaneous measurements from multiple devices due to the interference that would be generated by two similar devices, essentially what was done on existing devices A clinical study with the same design was conducted with volunteer human subjects, and the device was used to provide an FDA-cleared monitoring spirometer (Wright / Haloscale Respirometer, nSpire Health Inc., Longmont, CO) with minute ventilation ( MV) and tidal volume (TV) were compared.

  The intended use of the Wright / Halosscale Respirometer is: measurement and monitoring of the level of pulmonary ventilation achieved by intensive care patients during anesthesia and post-operative recovery. It measures the exhaled volume and is therefore either adequately ventilated, whether it is open or closed, or is a patient breathing spontaneously or mechanically Indicate whether the patient is ventilated.

  Philips Intelligent Monitors' is intended for use by healthcare professionals whenever there is a need to monitor a patient's physiological parameters. It is intended to monitor, record, and alarm multiple physiological parameters of adults, children, and newborns in healthcare facilities. MP20, MP30, MP40, and MP50 are additionally intended for use in transportation situations within a healthcare facility. ST Segment monitoring is restricted to adult patients only. Transcutaneous gas measurement (tcpO2 / tcpCO2) is limited to neonatal patients only. (Note: The Philips monitor can monitor many physiological variables. For this purpose of this test, only the respiratory frequency function is applicable.)

  The device uses bioimpedance measurements to calculate volume and respiration rate values. The Wright / Haloscale Respirometer uses an inline turbine to measure flow and calculate volume and flow. The Philips Intelligent Monitor uses impedance measurements to measure respiration rate.

  The accuracy of the measurement can be determined by clinical studies that simultaneously measure patient ventilation with both the device and the Wright / Haloscale Respirometer. A stopwatch was used to determine the actual breathing rate. Since bioimpedance measurements must be performed in living humans, the study was a clinical experiment.

  The data demonstrates that the values displayed on the device for volume and rate are equivalent to the values displayed on the Wright / Haloscale Respirometer for volume and flow without the need for spirometer calibration. ing. The electrical safety of this device bioimpedance measurement is consistent with existing devices that use bioimpedance measurement and comply with electrical safety standards.

Clinical performance test:
Clinical studies compared this device with basic monitoring and simultaneous measurements from the Wright / Haloscale Respirometer. (Respiration rate was calculated using a stopwatch.) Twenty subjects representing a wide range of intended patients participated in the study. (For 9 women and 11 men, age range: 22-80, BMI range: 18.7-41.8.) The study involved two sessions for each subject, Electrodes were applied and each subject performed 20 breathing tests.
Tidal volume, minute ventilation, and respiratory rate were measured simultaneously by the device and the Wright spirometer. Each subject returned 24 hours after the first session with the original electrode still attached. A second set of 20 breath tests was performed.

  The results of the study are shown in Table 1:

  The results show clinically relevant accuracy over a 24 hour period. Based on the results of non-clinical and clinical tests, and comparison of intended use, the device is substantially equivalent to the device and the Wright / Haloscale Respirometer with respect to intended use, safety, and efficacy It is.

Exemplary Device FIG. 1 illustrates a preferred device 100 embodiment of the present invention. Preferably, the device 100 includes an outer case 105 and a touch screen 110. Although a touch screen is shown, other forms of input devices (eg, keyboard, mouse, microphone) can also be used to input information into device 100. FIG. 2 is a rear view of the device 100. Device 100 may additionally include input ports 115A-C, power connector 120, and pole clamp 125. Device 100 may additionally include an audible or visual alert system, such as a speaker or a light. Device 100 may be capable of connecting to a local area network and / or a wide area network, either by wired connection and / or wireless.

  Although three ports 115A-C are shown, the device 100 may contain any number of ports. Preferably, ports 115A-C connect to, receive information from, and / or control peripheral devices (eg, ventilators, EKG machines, spirometers, and other medical devices) and sensors. It is configured. Ports 115A-B can all be the same type of port, or different types of ports (eg, USB ports, proprietary ports, serial or parallel ports, firewire ports, and Ethernet ports). For example, the device 100 may be configured to connect to the cable 330 shown in FIG. Cable 330 is preferably configured to couple pad set 440 (shown in FIG. 4) and device 100 and to send signals to and from pad set 440. Yes. The cable 330 can be a proprietary cable with a proprietary connector or can be a general purpose cable (eg, a USB cable). In some embodiments, the pad set 440 may be capable of communicating with the device 100 wirelessly. FIG. 5 shows a preferred installation of the pad set 440 on the human torso. Other configurations and installations of the pad set 440 are possible.

  6A-E show screenshots of the graphical user interface (GUI) of device 100. FIG. As can be seen in FIGS. 6A-C, the GUI shows the patient breath 650 graph, patient MV and predicted MV 655 and related graph 657, patient TV 660 and related graph 663, and patient RR 665. And associated graphs 667 can be displayed. In addition, there may be several selectable icons 670A-D. In addition, various displays in the GUI may be selectable to provide more information. The GUI may be customizable. For example, different data can be displayed at different locations in the GUI, and more data can be added to or removed from the GUI. Moreover, more or fewer icons can be displayed on the GUI.

  The exemplary patient shown in FIG. 6A is a patient without an opioid effect on their breathing. The exemplary patient shown in FIG. 6B is a patient whose breathing plateaued due to opioids. The exemplary patient shown in FIG. 6C is a patient whose respiration has plateaued over time due to opioids. Additionally, FIG. 6C shows the cardiac signal superimposed on the respiratory signal.

  FIG. 6D shows an example of a menu in the GUI, where the menu shown is an option for setting an alarm due to the duration of MV / TV / RR and the apnea detection period (No Breath Detected) Is shown. These options can be set by the caregiver based on the patient being monitored, or can be set automatically by the device based on the received data. Moreover, as shown in FIG. 6E, the menu has an option to set a custom RR-HR cutoff as disclosed herein.

  Other embodiments and uses of the invention will be apparent to those skilled in the art from consideration of the specification and implementation of the invention disclosed herein. All references cited herein, including all publications, US and foreign patents and patent applications, are specifically and entirely incorporated by reference. The term “comprising”, whenever used, is intended to include the terms “consisting of” and “consisting essentially of”. . Moreover, the terms “comprising”, “including”, and “containing” are not intended to be limiting. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Claims (23)

A respiratory monitoring system,
A computing device;
An electrode pad set configured to be coupled to a patient;
Computing devices
A processor;
At least one graphical user interface (GUI) in communication with the processor;
At least one sensor input in communication with the processor;
The electrode pad set is connectable to the sensor input, receives electrical signals from the computing device, detects bioimpedance signals through the patient's torso,
The processor is based on the detected bioimpedance signal without the need for both calibration to a known value and baseline collected during normal ventilation and without patient assistance. , Minute ventilation (MV), percent of expected MV, tidal ventilation (TV), percent of expected TV, respiratory rate (RR), and percent of expected RR or Several are decided in real time,
The GUI is determined among minute ventilation (MV), expected MV percent, tidal ventilation (TV), expected TV percent, respiratory rate (RR), and expected RR percent. Output one or more in real time,
Respiration monitoring system.   The respiratory monitoring system of claim 1, wherein the system provides an indication of at least one of hyperventilation, normal ventilation, and hypoventilation.   The respiratory monitoring of claim 1, wherein the system provides an indication of at least one hypoventilation, change in respiratory signal waveform, change in inspiratory expiration ratio, and inspiration plateau development based on opioid-induced respiratory depression. system.   The respiratory monitoring system of claim 1, wherein the computing device is configured to provide continuous measurement of ventilation within one minute of entering patient demographics into the device.   The respiratory monitoring system of claim 4, wherein the demographic is at least one of a patient's height, weight, and gender.   The computing device is configured to provide continuous measurement of ventilation without the need for patient-specific calibration to the ventilator and the need for a baseline when the patient is breathing normally. The respiratory monitoring system according to claim 4.   The respiratory monitoring of claim 1, wherein the computing device is configured to provide continuous measurement of ventilation as soon as the electrode is attached to the device and without entering demographic data. system.   The respiratory monitoring system of claim 1, wherein patient cooperation and control over patient breathing is not required.   The respiratory monitoring system of claim 1, wherein no device calibration is required for known ventilator, spirometer, and pneumotachometer readings.   The respiratory monitoring system of claim 1, wherein the computing device further comprises an HR-RR cutoff filter.   The respiratory monitoring system according to claim 10, wherein the HR-RR cutoff filter filters the respiratory signal and the cardiac signal based on a predetermined heart rate cutoff point.   The respiratory monitoring system of claim 10, wherein the heart rate cutoff point is one of 30, 40, 50, or 60 beat per minute (bpm).   The respiratory monitoring system of claim 11, wherein the heart rate cutoff point is based on at least one of patient demographics, MV or expected MV percentage, and rapid superficial respiratory index.   The respiratory monitoring system of claim 11, wherein the heart rate cutoff point is entered manually or automatically updated by a computing device.   The HR-RR cut-off filter is a measure of the gain of the impedance signal, a scaling factor with respect to the absolute value of the impedance trace displayed on the GUI, an indication of the decrease in tidal volume, an indication of the sedation level, and The respiratory monitoring system of claim 10, providing at least one of a diagnosis of a respiratory disorder.   The respiratory monitoring system of claim 1, further comprising at least one audible or visual alarm.   The at least one audible or visual alarm is set based on at least one of a patient disease state, a physician assessment, a clinical or therapeutic environment, a physiological measurement, or an external reference. 16. The respiratory monitoring system according to 16.   16. The respiratory monitoring system of claim 15, wherein at least one audible or visual alarm is adaptive.   The respiratory monitoring system of claim 1, wherein an expected MV is calculated based on a patient's height, weight, and gender.   20. The respiratory monitoring system of claim 19, wherein the expected MV calculation further comprises at least one of patient specific physiology, anatomy, morphology, or topology.   Whether the system is well conscious, unconscious, alert, dying, intubated with a ventilator, respiratory distress, or after sedation The respiratory monitoring system of claim 1, wherein the respiratory monitoring system is configured for use with a patient that is one of the following.   The respiratory monitoring system of claim 1, wherein the system is non-invasive.   The respiratory monitoring system of claim 1, further comprising a patient cable coupling the electrode pad set to the computing device, wherein the patient cable is configured to transmit high frequency current to the patient via the electrode pad set.

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