WO2020103281A1 - Apparatus for detecting exhaled gas and detection method - Google Patents

Abstract

Disclosed is an apparatus for detecting exhaled gas, the apparatus comprising a respiratory inlet end; a switch valve used for controlling the inflow of exhaled gas; a first pipeline, with an inlet end of the first pipeline being in communication with an outlet end of the switch valve, and an outlet end thereof being in communication with the atmosphere; a gas sensor used for detecting the concentration of gas to be detected in the exhaled gas; a power device connected to the gas sensor and used for continuously delivering the gas inhaled from the respiratory inlet end, in a second flow, to the gas sensor; and a control device used for controlling the gas sensor, the switch valve and the power device and performing information collection, processing, storage and communication. A method for detecting exhaled gas using the above detection apparatus is further provided. By means of the detection apparatus and detection method provided by the present invention, not only is the volume of the apparatus reduced, but the expiratory time of a user is also shortened, and the detection precision of the apparatus is improved.

Description

Exhaled gas detection equipment and detection method Technical field

The invention relates to the technical field of exhaled gas analysis, in particular to an exhaled gas detection device and a detection method.

Background technique

Part of the body's metabolism products are transported from the blood to the lungs, where they appear in the exhaled air through gas exchange in the alveoli. Existing research shows that human exhaled breath includes various compounds such as oxygen, carbon dioxide, nitric oxide, etc. Through qualitative or quantitative analysis and detection of exhaled breath, it can reflect the body's metabolism or pathological conditions, and some substances may even become a disease Biomarkers such as: exhaled nitric oxide can be used for the detection of respiratory diseases such as asthma; exhaled carbon monoxide can be used for the detection of respiratory diseases such as COPD; exhaled hydrogen and exhaled methane can be used for the detection of digestive system diseases; exhaled ammonia It can be used for Helicobacter pylori detection; exhaled aldehyde can be used for oxidative stress detection; exhaled sulfide can be used for lung function detection. In some developed countries, corresponding standards have been formulated for some gas detection technologies. For example, Europe and the United States developed recommended standards for exhaled NO detection in 1997 and 1999, and jointly formulated and published the standard in 2005 ("ATS / ERS Recommendations for Standardized Procedures for the Online Online and Offline Measurement for Exhaled Low Respiratory Nitric Oxide and Nasal Nitric Oxide, 2005 ", ATS is the abbreviation of American Thoracic Society, ERS is the abbreviation of European Respiratory Society, hereinafter referred to as" Standard "). Therefore, the analysis and detection of exhaled breath, as a new type of clinical auxiliary diagnosis method, has broad application prospects in the field of medical diagnosis.

Existing exhaled gas detection technology has the disadvantage of not being able to balance portability and accuracy. The technical solution of the gas inspection equipment of the Swedish Erokelin Company and the Wuxi Shangwo Company is to collect the exhaled gas through the gas volume, and then use the pump to continuously send the collected gas to the gas sensor at a smaller flow rate. Although this technology can guarantee The accuracy of the detection results, but due to the increase of the gas volume structure, so that the size of the detection device increases, and it takes a long time to eliminate the interference gas. The technical solution adopted by the British Bedfont testing equipment is to expel most of the exhaled air into the atmosphere during exhalation, a small part of the gas is sent to the gas sensor for detection by the pump, and the detection process is ended when the exhalation stops. Although this solution has greatly improved The portability of the detection equipment, but it requires a long breath sampling time during the detection process, which seriously reduces the accuracy of the detection results for children, the elderly, and people with breathing disabilities.

In view of the shortcomings of the prior art, the present invention provides an exhaled gas detection device and method, which not only reduces the volume of the device, but also shortens the user's exhalation time and improves the detection accuracy of the device.

Summary of the invention

The invention provides an exhaled gas detection equipment and a detection method, which are used to solve the problems of the existing exhaled gas detection equipment with large volume and long exhalation time.

An object of the present invention is to provide an exhaled gas detection device, including:

At the breath inlet, the user exhales the first pressure and the first flow of gas from the breath inlet;

On-off valve, used to control the inflow of exhaled gas;

A first pipeline, the inlet end of the first pipeline communicates with the outlet end of the on-off valve, and the outlet end communicates with the atmosphere;

Gas sensor, used to detect the concentration of the gas to be detected in the exhaled gas;

A power device, the power device is connected to the gas sensor, and is used to continuously deliver the gas inhaled from the breathing inlet end to the gas sensor at a second flow rate;

A control device that controls the gas sensor, on-off valve, and power device, and collects, processes, stores, and communicates information.

Further, the inner diameter of the first pipeline is D, and the length is L, where L / D> 50.

Further, the second flow rate is smaller than the first flow rate.

Further, the exhaled gas detection device further includes a flow adjustment device, which is provided in the air path between the breathing inlet end and the on-off valve to control the flow of exhaled gas.

Further, the exhaled gas detection device further includes a pressure sensor and a flow sensor, the pressure sensor is used to detect the gas pressure exhaled from the breathing inlet end, and the flow sensor is used to detect the gas flow exhaled from the breathing inlet end.

Further, the exhaled gas detection device further includes a second pipeline and a first filtration unit, one end of the second pipeline communicates with the breathing inlet end, and the other end communicates with the atmosphere, the first filtration The unit is provided on the second pipeline and is used to filter the gas to be detected existing in the atmosphere.

Further, the exhaled gas detection device further includes a second filter unit, which is provided in the air path between the breathing inlet end and the second pipeline, and is used to filter impurities in the exhaled gas.

Further, the exhaled gas detection device further includes a display terminal for displaying data to the user and receiving user commands and settings.

Further, the gas to be detected includes but is not limited to exhaled nitric oxide, exhaled carbon monoxide, exhaled carbon dioxide, exhaled oxygen, exhaled hydrogen, exhaled methane, exhaled ammonia, exhaled aldehyde and exhaled sulfide .

Another object of the present invention is to provide an exhaled gas detection method suitable for the exhaled gas detection device as described above, including the following steps:

S1, breathing gas from the breath inlet, the first pressure and the first flow of gas are exhaled;

S2. Open the on-off valve, and the power device draws gas to the gas sensor for detection at the second flow rate;

S3. After reaching the expiration time requirement, the first valve is closed, and the power device continues to extract the exhaled gas remaining in the first pipeline at the second flow rate to the gas sensor for detection, thereby obtaining the concentration of the gas to be detected.

The exhaled gas detection equipment and detection method provided by the present invention have the following advantages: 1. Reduce the user's exhalation time, which can be shortened to the minimum exhalation time recommended by the "Standard" and reduce the detection difficulty; 2. Increase the overall The detection time improves the detection accuracy of the device; 3. It reduces the size of the device and is easy to carry.

BRIEF DESCRIPTION

FIG. 1 is a structural block diagram of an exhaled gas detection device in a first embodiment of the present invention.

2 is a structural block diagram of an exhaled gas detection device in a second embodiment of the present invention.

FIG. 3 is a block diagram of steps of a method for detecting exhaled gas in a specific embodiment of the present invention.

detailed description

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments.

As shown in FIG. 1, the first embodiment of the present invention provides an exhaled gas detection device, which includes a breathing inlet end 1 and a user exhales from the breathing inlet end 1 a gas with a first pressure and a first flow rate; an on-off valve 2 , Used to control the inflow of exhaled gas; the first pipeline 3, the inlet end of the first pipeline 3 communicates with the outlet end of the on-off valve 2, and the outlet end communicates with the atmosphere; the gas sensor 5 is used to Detect the concentration of the gas to be detected in the exhaled gas; the power device 4 is connected to the gas sensor 5 for continuously sending the gas inhaled from the breath inlet end 4 to the gas sensor 5 at the second flow rate; the control device 6 The control device 6 controls the gas sensor 5, on-off valve 2, and power device 4, and collects, processes, stores, and communicates information.

In this embodiment, the power device 4 is a fan or a pump. The second flow rate can be adjusted by adjusting and controlling the power of the power device 4.

Among them, the gas to be detected includes but is not limited to exhaled nitric oxide, exhaled carbon monoxide, exhaled carbon dioxide, exhaled oxygen, exhaled hydrogen, exhaled methane, exhaled ammonia, exhaled aldehyde and exhaled sulfide.

During the user's exhalation, part of the exhaled gas is continuously delivered to the gas sensor 5 through the power device 4 at the second flow rate, and the other part of the gas is discharged from the atmosphere through the first pipeline 3; The valve 2 is opened and closed, and the power device 4 continues to extract the remaining exhaled gas in the first pipeline 3 to the gas sensor 5 at the second flow rate, thereby obtaining the concentration of the gas to be detected.

There is no gas volume in this solution, which reduces the volume of the device; when the expiration is completed, the power device can continue to extract the exhaled gas remaining in the first pipeline for detection, which can relatively shorten the user's exhalation time, To reduce the difficulty of detection, this technical solution can shorten the exhaled breath sampling time to the minimum exhaled breath recommended by the Standard (4 seconds for children and 6 seconds for adults); it increases the overall detection time, thus improving the detection accuracy of the device.

Based on the first embodiment, the present invention proposes a second embodiment. As shown in FIG. 2, the gas to be detected in this embodiment is exhaled nitric oxide, and the gas sensor is a NO sensor.

It should be noted that the "Standards" jointly developed by Europe and the United States in 2005 are used to guide how to conduct tests and use the test results for the diagnosis and evaluation of the effectiveness of respiratory diseases such as asthma. Due to the detection accuracy of the NO sensor, during the detection of exhaled nitric oxide, the amount of exhaled gas usually needs to meet certain requirements. The present invention adopts the expiratory pressure and expiratory flow rate recommended by "Standard", the first flow rate should be not less than 45ml / s, and the first pressure is between 5cm H ₂ O column and 20cm H ₂ O column; During the detection process, the second flow rate is determined according to the detection accuracy of the NO sensor. Normally, the second flow rate is between 0.5 ml / s and 15 ml / s.

Further, the inner diameter of the first pipeline 3 is D, and the length is L, where L / D> 50. This solution is similar to the principle of plug flow. When the L / D of the first pipeline 3 is greater than 50, the gas in the tube goes forward in the flow direction without axial mixing and diffusion, thus preventing the air from being mixed with the exhaled gas.

Further, the exhaled gas detection device further includes a flow adjustment device 7, which is provided in the air path between the breath inlet 1 and the on-off valve 2 for controlling the flow of exhaled gas. "Standard" recommends that exhaled nitric oxide requires a breath test at a fixed exhalation flow rate of 50ml / s (± 10%), and the flow adjustment device 7 can adjust the exhaled gas to 50ml / s (± 10%) Fixed flow rate.

Further, the exhaled gas detection device further includes a pressure sensor 8 and a flow sensor 9, the pressure sensor 8 is used to detect the pressure of the gas exhaled from the breathing inlet end 1, the flow sensor 9 is used to detect the breathing inlet end 1 Exhaled gas flow. This solution can detect the pressure and flow of exhaled gas in real time by setting the pressure sensor and flow sensor, so that the exhaled gas that meets the demand can be accurately collected.

Further, the exhaled gas detection device further includes a second pipeline 10 and a first filter unit 11, one end of the second pipeline 10 communicates with the breathing inlet end 1, and the other end communicates with the atmosphere. The first filter unit 11 is provided on the second pipeline 10 and is used to filter the nitric oxide present in the atmosphere, thereby avoiding the interference of the nitric oxide in the air with subsequent detection results, and making the detection results more accurate.

Further, the exhaled gas detection device further includes a second filter unit 12 that is disposed in the air path between the breathing inlet end 1 and the second pipeline 10. In this solution, the second filter unit 12 is used to filter impurities in the exhaled air, such as saliva, foam, etc., which further improves the accuracy of the exhaled air detection results.

Further, the exhaled gas detection device further includes a display terminal 13 for displaying data to the user and receiving user commands and settings.

The present invention also provides an exhaled gas detection method. As shown in FIG. 3, the steps of using the exhaled gas detection device as described above to detect exhaled nitric oxide are as follows:

S1. Breathe gas from the breath inlet 1 and monitor the pressure and flow of the exhaled gas through the pressure sensor 8 and the flow sensor 9 to reach the first pressure P ₁ and the first flow Q _{1 respectively} . If no ≥, you need to exhale again; 5 cm H ₂ O≤P ₁ ≤20cmH ₂ O, Q ₁ ≥45ml / s;

S2, by adjusting the flow rate of the flow regulating device 7 to 50ml / s (± 10%) , the switching valve 2 is opened, the power unit 4 at a second flow rate Q ₂ gas is extracted to detect the NO sensor 5; wherein 0.5ml / s≤Q ₂ ≤15ml / s;

S3. After reaching the expiratory time requirement (at least 4 seconds for children, at least 6 seconds for adults), close the on-off valve 2 and the power device 4 continues to extract the remaining exhaled gas in the first pipeline 3 to the NO sensor 5 at the second flow rate Q2 Test to obtain the concentration of exhaled nitric oxide; if the expiratory time is not met, you need to exhale again.

In the present invention, there are several options for the time when the power plant starts to pump down:

1. When the user begins to exhale, the power device performs a suction test. This can extend the overall detection time of the NO sensor;

2. After the exhalation is completed, the power device starts to detect the gas. If the expiration fails, you can exhale again. This avoids wasting sensor time due to expiration failure;

3. After a certain period of exhalation, the power unit starts to detect the gas. This can not only reduce the invalid detection time of the sensor, but also extend the overall detection time of the sensor.

Preferably, the third solution is adopted in this embodiment, specifically:

The first pipeline 3 has an inner diameter of D = 0.4 cm, a length of L = 85 cm, and a volume of V = 10.68 ml. The flow rate adjusting device 7 controls the flow rate of exhaled gas to 50 ml / s, the preferred second flow rate is Q ₂ = 1.5 ml / s, and the pumping time of the power device 4 to the first line 3 is 7 seconds.

According to the study, the dead space in the oral cavity of children and adults is 50ml and 150ml respectively, and the expulsion time of the dead cavity in the oral cavity of children and adults is 1 according to the standard 50ml / s expiratory flow rate Seconds, 3 seconds.

In this embodiment, the exhalation time is the shortest exhalation time recommended by the Standard for children: 4 seconds (6 seconds for adults), that is, 4 seconds for children (6 seconds for adults) to stop exhaling. After the child exhales for 1 second (adults for 3 seconds), that is, after the dead space is expelled, the power device 4 starts to deflate, the NO sensor starts to detect, and the exhalation stops after 3 seconds, the on-off valve 2 is closed, and the power device 4 starts The exhaled gas remaining in the first pipeline 3 is extracted for 7 seconds. Therefore, the detection time of the NO sensor 5 is 10 seconds in total.

Compared with the first scheme and the second scheme, in this scheme, the power device starts to evacuate after the user expels the dead space gas, thereby reducing the invalid detection time of the NO sensor; on the other hand, because the user is exhaling The NO sensor has begun to detect, so the overall detection time of the sensor is extended, and the detection accuracy of the sensor is improved.

The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention should be included in the protection of the present invention Within range.

Claims (10)

1. An exhaled gas detection device, characterized in that it includes:

   At the breath inlet, the user exhales the first pressure and the first flow of gas from the breath inlet;

   On-off valve, used to control the inflow of exhaled gas;

   A first pipeline, the inlet end of the first pipeline communicates with the outlet end of the on-off valve, and the outlet end communicates with the atmosphere;

   Gas sensor, used to detect the concentration of the gas to be detected in the exhaled gas;

   A power device, the power device is connected to the gas sensor, and is used to continuously deliver the gas inhaled from the breathing inlet end to the gas sensor at a second flow rate;

   A control device that controls the gas sensor, on-off valve, and power device, and collects, processes, stores, and communicates information.
2. The exhaled gas detection device according to claim 1, wherein the inner diameter of the first pipeline is D and the length is L, where L / D> 50.
3. The exhaled gas detection device according to claim 2, wherein the second flow rate is smaller than the first flow rate.
4. The exhaled gas detection device according to claim 3, further comprising a flow rate adjusting device, the flow rate adjusting device is provided in the air path between the breathing inlet end and the on-off valve to control the flow rate of the exhaled gas.
5. The exhaled gas detection device according to claim 4, further comprising a pressure sensor and a flow sensor, the pressure sensor is used to detect the pressure of the gas exhaled from the breathing inlet end, and the flow sensor is used to detect the breathing gas inlet The gas flow exhaled at the end.
6. The exhaled gas detection device according to claim 5, further comprising a second pipeline and a first filter unit, one end of the second pipeline is connected to the breathing inlet end, and the other end is connected to the atmosphere The first filter unit is provided on the second pipeline, and is used to filter the gas to be detected in the atmosphere.
7. The exhaled gas detection device according to claim 6, further comprising a second filter unit, the second filter unit is provided in the air path between the breathing inlet end and the second pipeline for filtering exhaled Impurities in the gas.
8. The exhaled gas detection device according to claim 7, further comprising a display terminal for displaying data to the user and receiving user commands and settings.
9. The exhaled gas detection device according to claim 1, wherein the gas to be detected includes but is not limited to exhaled nitric oxide, exhaled carbon monoxide, exhaled carbon dioxide, exhaled oxygen, exhaled hydrogen, and exhaled methane , Exhaled breath ammonia, exhaled breath aldehyde and exhaled breath sulfide.
10. An exhaled gas detection method suitable for the exhaled gas detection device according to claim 1, comprising the following steps:

    S1, breathing gas from the breath inlet, the first pressure and the first flow of gas are exhaled;

    S2. Open the on-off valve, and the power device draws gas to the gas sensor for detection at the second flow rate;

    S3. After reaching the expiratory time requirement, the first valve is closed, and the power device continues to extract the remaining exhaled gas in the first pipeline at the second flow rate to the gas sensor for detection, thereby obtaining the concentration of the gas to be detected.

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