GB2523180A

GB2523180A - A mask for measuring the composition of exhaled breath

Info

Publication number: GB2523180A
Application number: GB1402809.6A
Authority: GB
Inventors: Aubrey Gordon Storey; Bruce Thomas Grange Wardrop; Paul O'leary
Original assignee: Waterford Institute of Technology
Current assignee: Waterford Institute of Technology
Priority date: 2014-02-18
Filing date: 2014-02-18
Publication date: 2015-08-19
Also published as: WO2015124580A1; GB201402809D0

Abstract

A mask 100 for measuring a composition of exhaled and/or inhaled breath, the mask comprising a first sensing means for sensing one or more constituents in the exhaled/inhaled breath to measure metabolism and other responses to physical activity. The first sensing means may comprise an oxygen sensor 135A, a carbon dioxide sensor 135B, an air flow meter 135D or be operable to sense ammonia, acetone, nitric oxide 135C or isoprene concentration. The mask may comprise a second sensing means 145 wherein the second sensing means may comprise an air flow meter, a temperature sensor or a humidity sensor. The first sensing means may be mounted on a panel 140 which may be mounted adjacent to a flow of exhaled air A. The mask may comprise one or more membranes 150, 155 and contain a consumable insert for facilitating hygienic use by multiple subjects.

Description

A mask for measuring the composition of exhaled breath

Field of the Invention

The present teaching relates to a mask for measuring the composition of exhaled breath. In particular but not limited to, the present teaching is directed to a mask for measuring metabolic and other physiological responses to activity based on the composition of exhaled breath. The disclosure also relates to mask for monitoring the well being of living mammals by measuring the composition of exhaled and/or inhaled breath.

Background

The maximal rate of oxygen consumption (VO2max) is the criterion measure of an person's cardiorespiratory fitness. Assessment of VO2max for the purpose of monitoring and prescription exercise training to athletes and cardiac rehabilitation patients occurs routinely in exercise science laboratories worldwide. Exercise prescription is optimally expressed in terms of proportion of VO2max or V02 reserve.

Currently equipment required to monitor V02 is mostly cumbersome, expensive, and in general confined to laboratory environments. No such monitor is currently on the market to enable continuous and affordable V02 monitoring of exercise training in field environments.

There is therefore a need for a mask which addresses at least some of the

drawbacks of the prior art.

Summary

The present teaching relates to a mask for measuring a composition of exhaled breath. In particular, the present teaching is directed to a mask for measuring metabolic and other physiological responses to activity based on the composition of exhaled breath.

The disclosure also relates to mask for monitoring the well being of living mammals by measuring the composition of exhaled and/or inhaled breath.

Accordingly, the present teaching relates to a mask for measuring the composition of exhaled breath as detailed in claim 1. Furthermore, the presentteaching relates to a method for measuring physiological responses to exercise based on the composition of exhaled breath.

In one aspect a mask is provided for measuring a composition of exhaled breath, the mask comprising: an inhalation port through which air is inhaled, an exhaust port through which exhaled breath exits the mask, an expired air-flow channel for accommodating the flow of exhaled breath, and a first sensing means for sensing one or more consituents in the exhaled breath.

In another aspect a second sensing means is in communication with the inhalation port for monitoring air characteristics during inhalation. Advantageously, the second sensing means comprises an air flow meter. Preferably, the second sensing means comprises a temperature sensor. Ideally, the second sensing means comprises a humidity sensor.

In a further aspect, the first sensing means comprises an oxygen sensor.

Advantageously, the first sensing means comprises a carbon dioxide sensor. Ideally, the first sensing means comprises an air flow meter. In one example, the first sensing means comprises a plurality of sensors operably mounted on a panel. Preferably, the panel is mounted adjacent the expired air-flow channel.

In one aspect a battery is provided for powering the first sensing means.

In an exemplary arrangement, one or more mask membranes define an exhalation channel. Advantageously, an exhalation port is in fluid communication with the exhalation channel. Ideally, one or more mask membranes are configured to enclose one or more exhalation cavities of an individual. Preferably, an inner and outer mask membrane is provided which together define the exhalation channel.

In another aspect, a communication module is in communication with the first sensing means. Advantageously, the communication module is operable for transmitting sensed data to a remote computing means for analysis thereof.

In one aspect, the first sensing means is operable for measuring ammonia concentration in the exhaled breath. Advantageously, the first sensing means is operable for measuring acetone concentration in the exhaled breath. Ideally, the fiist sensing means is operable for measuring nitric oxide concentration in the exhaled breath. In one example, the first sensing means is operable for measuring isoprene concentration in the exhaled breath.

The present teaching is also relates to a method of montoring physiological responses of an individual to physical exercise; the method comprising: the individual wearing the mask for measuring a composition of exhaled breath while exercising, and using the mask to measure one or more gases in the exhaled breath and/or inhaled breath of the individual.

Advantageously, the one or more gases include at least one of oxygen, carbon dioxide, acetone, nitric oxide and isoprene. Advantageously, a combination of gases are measured simultaneously.

The present teaching further relates to a mask for measuring a composition of exhaled and/or inhaled breath, the mask comprising: an inhalation port through which air is inhaled, an exhaust port through which exhaled breath exits the mask, an expired air-flow channel for accommodating the flow of exhaled breath, and a sensing means for sensing one or more consituents in the exhaled and/or inhaled breath.

Brief Description of the Drawings

The present teaching will now be described with reference to the accompanying drawings in which: Figure 1 is a perspective view of a mask in accordance with the present teaching; Figure 2 is another perspective view of the mask.

Detailed Description of the Drawings

The present teaching will now be described with reference to an exemplary mask for measuring the composition of exhaled breath and/or inhaled. It will be understood that the exemplary mask is provided to assist in an understanding of the present teaching and is not to be construed as limiting in any fashion. Furthermore, features or elements that are described with reference to any one Figure may be interchanged with those of other Figures or other equivalent elements without departing from the spirit of the present teaching.

Referring to the drawings there is provided a mask 100 for measuring the composition of exhaled breath. The mask 100 is configured for measuring metabolic and other physiological responses of an individual to exercise based on the composition of exhaled breath. The mask 100 may also be used for monitoring the well being of living mammals by measuring the composition of exhaled and/or inhaled breath. The mask 100 consists of a combination of miniature sensors incorporated into an ergonomic design to be worn about the face over the mouth and nose. The mask 100 has a sensor array that can detect the presence and quantity of selected gases and/or volatile organic compounds (VOC) in the expired air. Analysis of the primary respiratory gases such as oxygen (02) and/or carbon dioxide (002) is the mainstay of exercise physiology, as fluctuations in these gasses reflect changes in metabolism resulting from variation in exercise intensity and/or fuel (carbohydrate/fat) utilisation. Furthermore, the pattern of VOC in the expired air serves as an additional biomarker for further relevant metabolic proctsses and as a potentially sensitive indicator of fluctuation in pulmonary blood flow and respiratory air flow.

In an exemplary embodiment, the mask 100 comprises an inhalation port 105 through which air is inhaled by an individual 110. An air-flow channel 115 extends between an exhalation port 120 and an exhaust port 125. The exhalation port 120 is located adjacent the individuals 110 nose and mouth so that airexhaled by the individual 110 flows into the exhalation port 120 and along the air-flow channel 115 and exits the mask 100 through the exhaust port 125. A first sensing means 130 is located in the air-flow channel 130 for sensing metabolic and other physiological responses as the individual exercises based on the composition of the exhaled breath. The first sensing means may include primary sensors 135 such as an oxygen sensor 135A, a carbon dioxide sensor 135B, a nitrogen sensor 135C and an air mass flow sensor 1350. These sensors are provided by way of example only, it is not intended to limit The present teaching to these particular sensors as other sensors may also be included if desired.The primary sensors 135 are provided on a panel 140 which is mounted adjacent the air-flow channel 130 so that the primary sensors are in fluid communication with the air as it is being exhaled by the individual 110. The direction of flow of the exhaled breath is indicated by arrow A'. A second sensing means is arranged to be in communication with the inhalation port 105. The second sensing means 145 may include secondary sensors 145 such a temperature sensor, a humidity sensor, a air mas flow sensor. The air flow sensors may be equipped with a air mass flow inlet 137 and and air mass flow outlet 138 for facilitating the flow of air through the airflow sensor as the exhaled breathed flows along the air-flow channel 115. A thermocouple or a resistance thermometer 139 may be configured for sensing the temperature of the gas in the air-flow channel 115.

The mask 100 includes one or more mask membranes for enclosing one or more exhalation cavities (nose/mouth) of the individual 110. In the exemplary embodiment, an outer mask membrane 150 together with an inner mask membrane 155 define ai exhalation channel 160 for capturing exhaled air from the exhalation cavities of the individual 110. The exhalation channel 160 is in fluid communication with the exhalation air-flow channel 115. As the individual exhales the expired air flows into the exhalation channel and into the air-flow channel 115 and exits the mask 100 via the exhaust port 125. The primary sensors 135 measure the composition of the exhaled air which may include levels of gases such as oxygen/carbon dioxide and/or volatile organic compounds. The secondary sensors 145 measure the composition of the inhaled air which may include levels of gases such as oxygen/carbon dioxide and/or volatile organic compounds. Data which is sensed by the primary and/or secondary sensors 135, 145 may be transmitted by a communication module 170 to a remote computer for analysis. A circuit 180 electrically couples the primary and secondary sensors 135, 145 to the communication module 170. A power supply in the form of a battery 190 is configured to power the circuit 180. Thus the battery 190 electrically powers the primary and secondary sensors 135, 145 as well as the communication module 170. The circuit 180 may also include an atmospheric pressure meter 195 for measuring atmospheric pressure. By incorporating a battery into the mask 100 allows an athlete to wear the mask 100 when participating in a field sport such as soccer, football, hurling, basket ball, hockey, etc. It will be appreciated by those skilled in the art that it in a field sport environment it would not be practical to power the mask from a electricity mains supply outlet which may be a possibility in a laboratory environment but not while the athlete is playing on an outdoor field or pitch. Weighted importance can be assigned to sensor readings for measuring metabolic and other physiological responses b exercise based on the composition of the individuals 110 exhaled breath. Adaptive pattern recognition may be used when implementing continuous analysis of the VOC in real-time.

The primary and secondary sensors 135, 145 determine respiratory parameters by measuring both inspired and expired air flow, and the expired fractions of oxygen and carbon dioxide. Temperature and pressure gauges enable corrections to volume/flow measurements according to the gas laws. This raw data enables real-time breath-by-breath and time-averaged determination of the following respiratory variables both at rest and during exercise: * Minute rate of oxygen consumption (V02).

* Metabolic rate or rate of energy expenditure (EE).

* Inspired minute ventilation (Vi; the volume of air inspired each minute).

* Expired minute ventilation (VE; the volume of air expired each minute).

* Minute rate of carbon dioxide production (VCQ).

* Respiratory exchange ratio (VCO2/V02; this measure reflects the relative use of carbohydrates and lipids duhng exercise).

* Ventilatory equivalent for oxygen (VENO2).

* Ventilatory equivalent for carbon dioxide (this value, together with the VE/V02 can be used to determine the ventilatory threshold (VT), a threshold exercise intensity above which exercise cannot be sustained for prolonged durations (VENCO2).

* Cardiac output estimated according to the Fick method.

In addition to these continuous respiratory measures, the mask 100 may be configued for use in pulmonary function testing. Standard protocols may be used for determining the following: * Forced vital capacity (FVC) * Slow vital capacity (SVC) * Forced expiratory volume in one second (FE']1) * Flow/volume loops The mask 100 may be linked with other external inputs to enable simultaneous monitoring of blood pressure, blood 02 saturation, heart electrical activity (ECG) and galvanic skin response, each of which contributes additional clinically relevant information during exercise. The communication module 170 will wirelessly interface with mobile devices and/or smart glasses or any wireless compatible device to provide real-time biofeedback in a usable and actionable way. Through interfacing with such mobile devices on 4G and Wi-Fi networks it will be possible to upload live data to a cloud server which can then enable real-time remote monitoring by and interaction with coaches, physiologists or clinicians.

The advantages of the present teaching are many. The mask 100 provides the ability to detect gases, thus enabling greater scope for metabolic analysis It facilitates real-time monitoring of standard respiratory parameters (including respiratory frequency, ventilation (yE), V02, VCO2, respiratory exchange ratio (RER), ventilatory equivalents for 02 and C02) during a variety of activities. For example, ammonia concentration in expired air reflects changes in exercise intensity and is closely related to the lactate threshold The detection of acetone in exhaled breath provides an indication of lipid metabolism (especially relevant for diabetes and ultra-endurance exercise). The detection of nitric oxide in exhaled breath provides an indication of respiratory airway response to exercise (especially relevant for asthma). The detection of isoprene in exhaled breath reflects cholesterol/lipid metabolism. The primary sensors 135 are operable to measure one or more gases in the exhaled breath. The gases may include at least one of oxygen, carbon dioxide, acetone, nitric oxide and isoprene. Advantageously, a combination of gases in the exhaled breath may be measured simultaneously.The communication module 170 allows data from the sensors to be presented directly to the end-user in a real-time through interaction with the latest mobile technologies. The mask 100 has an ergonomic design that is comfortable to wear, enabling high quality measurements to be obtained in a range of field environments and during a wide range of different activities.

The mask 100 may be used for monitoring the performance of athletes in a variety of sports for whom physical fitness and/or body composition'nutrition are critical components of their performance. The mask 100 may used to monitohng patients for example, cardiovascular, metabolic and respiratory disease patients for whom exercise is a recommended component of their rehabilitation process. Weight loss exercisers who aim to achieve weight loss through a systematic and scientific method can wear the mask 100 while exercising. Fire fighters and other emergency response personnel who operate in threatening environments can wear the mask to monitor their respiratory health.The mask may comprises an insert 175 for facilitating hygenic use by multiple subjects. For example, in a team sport environment it is desireable that the mask may be worn by multiple users on different occasions. In particular, the insert 175 may be configured to isolate bodily fluid such as salvia from contaminating other portions of the mask 100. The insert 175 may be releasably replacable so that each team member when using the mask can use their own specific insert 175. In an exemplary arrangement, the insert 175 is a filter for locating adjacent the nose and/or mouth region in the mask 100.

While the present teaching has been described with reference to exemplary arrangements, it will be understood that it is not intended to limit the teaching of the present teaching to such arrangements as modifications may be made without departing from the spirit and scope of the present invention. It will be appreciated that gas sensors may also be provided for facilitating analysing inhaled breath. In one exemplary arrangementthe difference between inspired and expired gas concentrations are measured. Furthermore, sensors may be provided on the mask for measuring gas concentrations in the atmospheric air. While the mask 100 has been described as been worn by a person during exercise. It is not intended to limit the mask to be solely used by humans. It will be appreciated by those skilled in the art that the mask could be worn by high performance animal athletes such as race horses, camels or greyhounds. While the sensors have been described for sensing particular gases, it is not intended to limit the teaching to these gases as alternative gases may also be measured using the mask as will be appreciated by thoses skilled in the art.

In this way it will be understood that the present teaching is to be limited only insofar as is deemed necessary in the light of the appended claims.

Similarly the words comprises/comprising when used in the specification are used to specify the presence of stated features, integers, steps or components but do not preclude the presence or addition of one or more additional features, integers, steps, components or groups thereof.

Claims

Claims 1. A mask for measuring a composition of exhaled breath, the mask comprising: an inhalation pod through which air is inhaled, an exhaust pod through which exhaled breath exits the mask, an expired air-flow channel for accommodating the flow of exhaled breath, and a first sensing means for sensing one or more consituents in the exhaled breath.
2. A mask as claimed in claim 1, further comprising: a second sensing means for monitoring air characteristics during inhalation.
3. A mask as claimed in claim 2, wherein the second sensing means comprises an ar flow meter.
4. A mask as claimed in claim 2 or 3, wherein the second sensing means comprises a temperature sensor.
5. A mask as claimed in any one of claims 2 to 4, wherein the second sensing means comprises a humidity sensor.
6. A mask as claimed in any one of the preceding claims, wherein the first sensing means comprises an oxygen sensor.
7. A mask as claimed in any one of the preceding claims, wherein the first sensing means comprises a carbon dioxide sensor.
8. A mask as claimed in any one of the preceding claims, wherein the first sensing means comprises an air flow meter.
9. A mask as claimed in any one of the preceding claims, wherein the first sensing means comprises a plurality of sensors operably mounted on a panel.
10. A mask as claimed in claim 9, wherein the panel is mounted adjacent the expired air-flow channel.
11. A mask as claimed in any one of the preceding claims, further comprising a battery for powering the first sensing means.
12. A mask as claimed in any one of the preceding claims, further comprising one or more mask membranes defining an exhalation channel.
13. A mask as claimed in claim 12, wherein an exhalation port is in fluid communication with the exhalation channel.
14. A mask as claimed in claim 12 or 13, wherein the one or more mask membranes are configured to enclose one or more exhalation cavities of an individual.
15. A mask as claimed in any one of claims 12 to 14, wherein an inner and outer mask membranes is provided which together define the exhalation channel.
16. A mask as claimed in any one of the preceding claims, further comprising a communication module in communication with the first sensing means.
17. A mask as claimed in claim 16, wherein the communication module is operable for transmitting sensed data to a remote computing means for analysis thereof.
18. A mask as claimed in any one of the preceding claims, wherein the first sensing means is operable for measuring ammonia concentration in the exhaled breath.
19. A mask as claimed in any one of the preceding claims, wherein the first sensing means is operable for measuring acetone concentration in the exhaled breath.
20. A mask as claimed in any one of the preceding claims, wherein the first sensing means is operable for measuring nitric oxide concentration in the exhaled breath.
21. A mask as claimed in any one of the preceding claims, wherein the first sensing means is operable for measuring isoprene concentration in the exhaled breath.
22. A mask as claimed in any one of the preceding claims, wherein the consituents include one or more gases present in the exhaled breath.
23. A mask as claimed in any one of claims ito 22, wherein the consituents include one or more volatile organic compounds present in the exhaled breath.consituents.
24. A mask as claimed in any one of the preceding claims wherein, that the mask comprises a consumable insertfor facilitating hygenic use by multiple subjects.
25. A method of monitoring physiological responses of an individual to physical activity; the method comprising: the individual wearing the mask as claimed in any one of claims 1 to24 while exercising, and using the mask to measure one or more gases in an exhaled breath and/or inhaled breath of the individual.
26. A method as claimed in claim 25, wherein the one or more gases includes at least one of oxygen, carbon dioxide, acetone, nitric oxide and isoprene.
27. A method as claimed in claim 25, wherein a combination of gases are measured simultaneously.
28. A mask for measuring a composition of exhaled and/or inhaled breath, the mask comprising: an inhalation port through which air is inhaled, an exhaust port through which exhaled breath exits the mask, an expired air-flow channel for accommodating the flow of exhaled breath, and a sensing means for sensing one or more consituents in the exhaled and/or inhaled breath.
29. A mask substantially as described herein with reference to the accompanying drawings.