Multifunctional expired gas online sampling device and method thereof

Abstract

The invention provides a multifunctional expired gas online sampling device and a method thereof. The device comprises a pressure measuring system, a flow measuring system, a mode switching system and a cleaning system. The method comprises the following steps: before sampling, NC of the two-position three-way electromagnetic valve is closed, NO of the two-position three-way electromagnetic valve is opened, and gas in the expired gas online sampling device is emptied through the normally-open two-way electromagnetic valve; nO of the two-position three-way electromagnetic valve is closed, and NC is opened; air is blown into the expired air on-line sampling device through the blowing nozzle, expired air flows through the pressure sensor, the expired air pressure is measured, and saliva is collected into the saliva bin in a centralized mode; exhaled air flows from the high-pressure detection port to the low-pressure detection port, and the flow of the exhaled air is measured through the flow sensor; exhaled air flows to the electromagnetic valve frame from the low-pressure detection port, flows through the sampling port through the passage NO, and is collected by a sample container or analyzed on line by an analysis instrument; and the expired gas pressure, the expired gas flow and an online analysis result are displayed through a screen and a control system.

Description

Technical Field

[0001] The present invention relates to the technical field of gas sampling, and in particular to a multifunctional exhaled gas online sampling device and a method thereof. Background Art

[0002] Exhaled breath vapor (EBV) contains hundreds of endogenous volatile organic compounds (VOCs), which are byproducts of metabolism in health and disease, such as fishy odor for liver disease, acetone for diabetes, ammonia for kidney failure, NO for asthma, etc. Breath analysis has clinical and diagnostic potential. By measuring VOCs in exhaled breath samples, biomarker signatures of health conditions can be established, providing new clinical diagnostic tools.

[0003] Breath analysis is an attractive non-invasive patient diagnostic tool, but it is difficult to detect compounds at extremely low concentration levels. Gas chromatography, mass spectrometry, FeNO, ion mobility spectrometry, and laser absorption spectroscopy are widely used to separate and identify volatile organic compounds in human breath. Breath measurement conditions: exhaled flow, environment, breath holding, forced exhalation operation, and nasal contamination have an important impact on the concentration. A key issue in measuring the concentration of VOCs in exhaled air is how to sample the breath. Because the concentration of VOCs may change during transportation, storage, pretreatment, or during collection at the breath inlet.

[0004] Depending on the scope of medical diagnosis, breath can be sampled in two ways: mixed exhaled breath sampling and end-tidal sampling. The first method collects the total breath volume, which mainly includes air from the upper respiratory tract. The second method collects air (alveolar air) that is associated with blood components. There is currently no universal standard for breath sampling, but for the measurement of nitric oxide, it is recommended that exhaled breath is preferably collected and tested at a constant flow and pressure.

[0005] There are many breath sampling techniques currently in use, which are mainly divided into online (connecting the breathing device to the gas analyzer) and offline sampling (breath detection in a sample container, such as an air bag or enrichment detection with an adsorbent tube). In general, it is best to use online direct sampling technology. For this technology, the possibility of sample changes is minimized. At this time, the exhaled volume and other exhaled variables (for example, airway flow rate or pressure) are captured and displayed in real time. The test administrator can monitor the exhalation to ensure that it meets the requirements. However, in some cases, online sampling is not possible, and appropriate offline methods become much more convenient. However, the diffusion loss of breath gas in the storage bag or the adsorption on the inner surface and the interaction between the sample components will irreversibly change the original composition of the sample, thereby interfering with the final result of the analysis.

[0006] An analytical method for detecting acetone concentration in exhaled end gas (CN202111490775.8) discloses a method for offline collection of end exhaled gas: when the exhaled gas passes through the gas flow sensor set on the breathing tube from the blowing nozzle, when the blowing flow rate is greater than the set threshold, the sensor signal is transmitted to the solenoid valve, the solenoid valve switches the gas path, and the front end gas less than the flow rate setting value exhaled by the sampled person is discharged, and the gas at the end of the exhalation is collected in the Tedlar air bag, and the sampling air bag gradually becomes larger and is filled after one or more blowings. Although this patent can track the exhaled gas flow (indicator light) in real time, the exhaled gas flow is only used as a threshold, and constant pressure, constant flow, and fixed volume collection cannot be achieved, nor can the observer track parameters such as pressure and flow in real time. The sampling device cannot achieve online collection, nor can the sampling device be purged.

[0007] An enrichment device for improving the sensitivity of ammonia detection at the end of nasal exhalation (CN219417371U) discloses a method of using bypass detection to detect the real-time collected exhaled CO2 curve to determine the end of the nasal cavity for online sampling and enrichment, and at the same time uses the bypass principle to achieve the purge of ion mobility spectrum, but the device will cause part of the exhaled air to be lost, affecting the collection efficiency.

[0008] A portable exhaled breath collection device (CN209884147U), the volume of exhaled breath can be measured by a flow meter, and a three-way solenoid valve can realize the switching of the collection gas path. Using gas sensors, temperature and humidity sensors and pressure sensors as sensitive devices, the three-way solenoid valve and air pump are triggered to work, and the exhaled breath of the upper and lower respiratory tracts of the tested person can be collected. However, the design of the device is complex and is not suitable for online collection of exhaled breath.

[0009] Therefore, there is a need for an online exhaled breath sampling device to achieve online collection and automatic cleaning. Summary of the invention

[0010] In response to the technical problems raised above, a multifunctional exhaled air online sampling device and method thereof are provided. The present invention is used to collect air from the upper respiratory tract and alveoli for clinical research. After exhausting the dead gas from the equipment, the collector uses a mask (mouthpiece) with a biological filter to exhale, connects the gas collection end to the sample container or analytical instrument, and the exhaled air is automatically transferred to the sample container or analytical sampling port by the solenoid valve controlled by the data detected by the pressure sensor and the differential pressure flow sensor. Mixed exhaled air or end-tidal gas is automatically collected according to the program. Through the screen, the collector can obtain the control of the pressure and flow of the exhaled gas in real time, and adjust the force of breathing, and collect exhaled air at constant pressure, constant flow or constant volume.

[0011] The technical means adopted by the present invention are as follows:

[0012] A multifunctional exhaled breath online sampling device, comprising: a pressure measurement system, a flow measurement system, a mode switching system and a cleaning system, wherein:

[0013] The pressure measurement system is connected to the handle at one end and the flow measurement system at the other end for measuring the exhaled air pressure; the handle is connected to the mouthpiece;

[0014] The flow measurement system is connected to the pressure measurement system at one end and to the gas switching system at the other end for measuring the exhaled gas flow;

[0015] The mode switching system has one end connected to the flow measurement system and the other end connected to the cleaning system, and is used to switch the working mode of the exhaled breath online sampling device to the detection mode or the cleaning mode;

[0016] The cleaning system is connected to the mode switching system and is used for reverse cleaning of the exhaled breath online sampling device.

[0017] Furthermore, the pressure measurement system comprises: a sensor rack, a saliva chamber and a pressure sensor, wherein:

[0018] The sensor frame is a hollow structure, connected to the mouthpiece through a handle, a saliva tank is arranged below the sensor frame, a pressure sensor is arranged above the sensor frame, and a high-pressure detection port is arranged at the tail end of the sensor frame;

[0019] A sealing screw is arranged below the saliva tank. When the exhaled air online sampling device is in a cleaning mode, the sealing screw is removed to clean the saliva tank.

[0020] Furthermore, the flow measurement system comprises: an air resistance pipeline, a flow sensor, a high pressure detection port and a low pressure detection port, wherein:

[0021] The air resistance pipeline is connected to the sensor frame to block the exhaled air passage, driving the exhaled air to pass into the flow sensor from the high-pressure detection port; the flow sensor is a differential pressure flow sensor, one end of which is connected to the high-pressure detection port and the other end is connected to the low-pressure detection port.

[0022] Furthermore, the mode switching system comprises: a solenoid valve frame, a sampling port, an exhaust port and a two-position three-way solenoid valve, wherein:

[0023] The solenoid valve frame is a hollow structure, the front end of the solenoid valve frame is connected to the low-pressure detection port, the two-position three-way solenoid valve is arranged inside the solenoid valve frame, and the two-position three-way solenoid valve includes two passages, NO and NC. In the detection mode, NO is closed, NC is opened, and connected to the sampling port. In the cleaning mode, NC is closed, NO is opened, and connected to the exhaust port.

[0024] During online collection, the sampling port is connected to an analysis instrument to directly analyze the exhaled breath online; during offline collection, the sampling port is connected to a sample container to sample and collect the exhaled breath.

[0025] Furthermore, the cleaning system comprises: a three-way pipeline, a cleaning pump and a normally open two-way solenoid valve, wherein:

[0026] The three ports of the three-way pipe are respectively connected to the exhaust port, the cleaning pump and the normally open two-way solenoid valve; before sampling, the exhaled breath online sampling device empties the gas in the exhaled breath online sampling device through the normally open two-way solenoid valve;

[0027] The cleaning pump is used to blow high-pressure gas from the cleaning system through the mode switching system, the flow measurement system, the pressure measurement system, the handle in sequence in the cleaning mode, and out from the mouthpiece to complete the cleaning.

[0028] Furthermore, the exhaled breath online sampling device also includes a screen and a control system, which can display the measurement results of the pressure sensor and the flow sensor in real time, and can display the online analysis results of the analysis instrument in real time during online collection.

[0029] Corresponding to the multifunctional online exhaled breath sampling device in the present application, the present application also provides a multifunctional online exhaled breath sampling method, comprising:

[0030] Before sampling, the NC of the two-position three-way solenoid valve is closed and the NO is opened, and the gas in the exhaled breath online sampling device is emptied through the normally open two-way solenoid valve; then the NO of the two-position three-way solenoid valve is closed and the NC is opened;

[0031] Blow air into the exhaled air online sampling device through the mouthpiece, and the exhaled air flows through the pressure sensor to measure the exhaled air pressure, and the saliva is collected in the saliva tank;

[0032] The exhaled air flows from the high-pressure detection port to the low-pressure detection port, and the exhaled air flow rate is measured by the flow sensor;

[0033] The exhaled air flows from the low-pressure detection port to the solenoid valve frame, and flows through the sampling port through the passage NO, and is collected by a sample container or analyzed online by an analytical instrument;

[0034] The exhaled air pressure, exhaled air flow rate and online analysis results are displayed through the screen and control system.

[0035] Furthermore, the working method of the exhaled breath online sampling device in the cleaning mode is as follows:

[0036] Close the NC of the two-position three-way solenoid valve, open the NO, close the normally open two-way solenoid valve, turn on the cleaning pump to let the high-pressure gas flow from the cleaning system through the mode switching system, flow measurement system, pressure measurement system, handle, and blow out from the mouthpiece to complete the cleaning.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] The multifunctional exhaled breath online sampling device and method provided by the present invention include: a pressure measurement system, a flow measurement system, a mode switching system and a cleaning system, which can detect the pressure, flow and total volume of the breath in real time and realize automatic gas sampling in cooperation with the solenoid valve. The present invention can directly connect the sampling port to the sampling port of the device to realize online analysis of the breath, reduce interference, and ensure the original composition and morphology of the sample; it can also collect the breath VOC into the sample container, so that clinical respiratory researchers can break through geographical restrictions and realize the sharing of laboratory samples;

[0039] The multifunctional exhaled air online sampling device and method provided by the present invention can realize the air collection of the upper respiratory tract or alveoli for clinical research by selecting different control sampling parameters; the sampling device is also designed with automatic cleaning and automatic saliva collection functions, making the device more comprehensive. The device is an exhaled air VOC sampling device that is easy to assemble for studying respiratory air VOC, with small size, light weight, low cost, and easy to use in clinical and commercial environments. Based on the above reasons, the present invention can be widely promoted in the fields of gas sampling and so on. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0041] Figure 1 It is a schematic diagram of the structure of the multifunctional online exhaled breath sampling device in the present invention.

[0042] In the figure: 1. Mouthpiece; 2. Handle; 3. Sensor holder; 4. Sealing screw; 5. Water tank; 6. Air resistance pipeline; 7. Solenoid valve holder; 8a. Sample container; 8b. Analytical instrument; 9. Sampling port; 10. Exhaust port; 11. Three-way pipeline; 12. Normally open two-way solenoid valve; 13. Cleaning pump; 14. Two-position three-way solenoid valve; 15. Low-pressure detection port; 16. Flow sensor; 17. High-pressure detection port; 18. Pressure sensor; 19. Screen and control system. DETAILED DESCRIPTION

[0043] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0044] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0046] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0047] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0048] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0049] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0050] like Figure 1 As shown, the present invention provides a multifunctional exhaled breath online sampling device, including: a pressure measurement system, a flow measurement system, a mode switching system and a cleaning system, wherein:

[0051] A pressure measurement system, one end of which is connected to the handle 2 and the other end is connected to the flow measurement system, for measuring the exhaled air pressure; the handle 2 is connected to the mouthpiece 1;

[0052] During implementation, the mouthpiece 1 can be replaced by a mask or a blowpipe, and can be provided with or without a filter.

[0053] A flow measurement system, one end of which is connected to a pressure measurement system, and the other end is connected to a gas switching system for measuring the exhaled air flow;

[0054] A mode switching system, one end of which is connected to the flow measurement system and the other end is connected to the cleaning system, for switching the working mode of the exhaled breath online sampling device to a detection mode or a cleaning mode;

[0055] Cleaning system, connected to the mode switching system, for reverse cleaning of the exhaled breath online sampling device.

[0056] In specific implementation, as a preferred embodiment of the present invention, the pressure measurement system includes: a sensor frame 3, a water tank 5 and a pressure sensor 18, wherein:

[0057] The sensor frame 3 is a hollow structure, connected to the mouthpiece 1 through the handle 2, a saliva tank 5 is arranged below the sensor frame 3, a pressure sensor 18 is arranged above, and a high-pressure detection port 17 is arranged at the tail end of the sensor frame 3;

[0058] A sealing screw 4 is provided below the saliva chamber 5 . When the exhaled air online sampling device is in a cleaning mode, the sealing screw 4 is removed to clean the saliva chamber 5 .

[0059] During implementation, the pressure sensor 18 can be replaced or supplemented with a humidity sensor, a CO2 sensor, or other types of sensors according to actual detection requirements.

[0060] In specific implementation, as a preferred embodiment of the present invention, the flow measurement system includes: an air resistance pipeline 6, a flow sensor 16, a high pressure detection port 17 and a low pressure detection port 15, wherein:

[0061] The air blocking line 6 is connected to the sensor frame 3, blocking the exhaled air passage, driving the exhaled air to pass through the high pressure detection port 17 into the flow sensor 16; the flow sensor 16 is a differential pressure flow sensor, one end of which is connected to the high pressure detection port 17 and the other end is connected to the low pressure detection port 15.

[0062] During implementation, the flow sensor 16 can be replaced with other types of sensors according to detection requirements, such as a thermal flow sensor, an invasive flow sensor or a non-invasive flow sensor.

[0063] In specific implementation, as a preferred embodiment of the present invention, the mode switching system includes: a solenoid valve frame 7, a sampling port 9, an exhaust port 10 and a two-position three-way solenoid valve 14, wherein:

[0064] The solenoid valve frame 7 is a hollow structure, the front end of the solenoid valve frame 7 is connected to the low pressure detection port 15, and the two-position three-way solenoid valve 14 is arranged inside the solenoid valve frame 7. The two-position three-way solenoid valve 14 includes two passages, NO and NC. In the detection mode, NO is closed, NC is opened, and connected to the sampling port 9. In the cleaning mode, NC is closed, NO is opened, and connected to the exhaust port 10.

[0065] During online collection, the sampling port 9 is connected to the analysis instrument 8b to directly analyze the exhaled air online; during offline collection, the sampling port 9 is connected to the sample container 8a to sample and collect the exhaled air.

[0066] In specific implementation, as a preferred embodiment of the present invention, the cleaning system includes: a three-way pipe 11, a cleaning pump 13 and a normally open two-way solenoid valve 12, wherein:

[0067] The three ports of the three-way pipe 11 are respectively connected to the exhaust port 10, the cleaning pump 13 and the normally open two-way solenoid valve 12; before sampling, the exhaled air online sampling device empties the gas in the exhaled air online sampling device through the normally open two-way solenoid valve 12;

[0068] The cleaning pump 13 is used to blow high-pressure gas from the cleaning system through the mode switching system, the flow measurement system, the pressure measurement system, the handle 2 in sequence in the cleaning mode, and out from the mouthpiece 1 to complete the cleaning.

[0069] In specific implementation, as a preferred embodiment of the present invention, the exhaled breath online sampling device also includes a screen and a control system. The screen and the control system can display the measurement results of the pressure sensor 18 and the flow sensor 16 in real time. During online collection, the online analysis results of the analyzer 8b can be displayed in real time.

[0070] During implementation, the control system has the function of uploading the detected data in real time, which is convenient for the operator to check whether the exhaled breath collection is qualified.

[0071] Corresponding to the multifunctional online exhaled breath sampling device in the present application, the present application also provides a multifunctional online exhaled breath sampling method, comprising:

[0072] Before sampling, the NC of the two-position three-way solenoid valve 14 is closed and the NO is opened, and the gas in the exhaled breath online sampling device is emptied through the normally open two-way solenoid valve 12; then the NO of the two-position three-way solenoid valve 14 is closed and the NC is opened;

[0073] Blow air into the exhaled air online sampling device through the mouthpiece 1, the exhaled air flows through the pressure sensor 18, the exhaled air pressure is measured, and the saliva is collected in the saliva tank 5;

[0074] The exhaled air flows from the high pressure detection port 17 to the low pressure detection port 15, and the exhaled air flow rate is measured by the flow sensor 16;

[0075] The exhaled air flows from the low pressure detection port 15 to the electromagnetic valve frame 7, and flows through the sampling port 9 through the passage NO, and is collected by the sample container 8a or analyzed online by the analysis instrument 8b;

[0076] The exhaled air pressure, exhaled air flow and the results of the online analysis are displayed via the screen and control system 19 .

[0077] In specific implementation, as a preferred embodiment of the present invention, the working method of the exhaled breath online sampling device in the cleaning mode is as follows:

[0078] Close the NC of the two-position three-way solenoid valve 14, open the NO, close the normally open two-way solenoid valve 12, and start the cleaning pump 13 to let the high-pressure gas flow from the cleaning system through the mode switching system, the flow measurement system, the pressure measurement system, the handle 2 in sequence, and blow it out from the mouthpiece 1 to complete the cleaning.

[0079] Example

[0080] like Figure 1 As shown, the present invention provides a multifunctional exhaled breath online sampling device and method thereof. The exhaled breath online sampling device has two working modes: sampling and cleaning.

[0081] Sampling mode: the cleaning pump 13 is turned off, the normally open two-way solenoid valve 12 is turned on, and the gas is exhausted from the exhaust port 10. The collector holds the handle 2 and blows air into the device through the mouthpiece 1. At this time, the current pressure and flow will be displayed on the screen and control system 19. When the pressure or flow reaches the set value, the two-position three-way solenoid valve 14 switches NC to open, the screen and control system 19 will issue a prompt sound and start recording the volume of the collected gas, and the exhaled gas will be discharged from the sampling port 9. When the sampling port 9 is connected to the sample container 8a, offline collection is achieved, and online sampling is achieved when it is connected to the analyzer 8b. The device has multiple collection modes. The collector observes the sample pressure, flow or volume on the screen in real time, and adjusts it to the required sample pressure, flow or volume through positive feedback to achieve constant pressure, constant flow or constant volume sampling. Mixed exhaled sampling and end-tidal sampling can also be achieved through delay.

[0082] When the exhaled gas contains saliva during the collection process, it will gather in the saliva chamber 5 during the downward flow along the gas path. When the saliva is full, the sealing screw 4 can be turned to clean it. The screen and control system 19 has the function of uploading the detected data in real time, which is convenient for the operator to check whether the exhaled gas collection is qualified.

[0083] Cleaning mode: the cleaning pump 13 is turned on, the normally open two-way solenoid valve 12 is closed, the two-position three-way solenoid valve 14 is turned on, the device is reversely cleaned, and the gas is blown out from the mouthpiece 1 along the three-way pipe 11, the solenoid valve rack 7, the two-position three-way solenoid valve 14, the air resistance pipeline 6, the sensor rack 3, the handle 2, and finally blown out from the mouthpiece 1 to achieve reverse cleaning. The screen and control system 19 can set the cleaning time for easy operation.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multifunctional exhaled breath online sampling device, characterized in that: include: Pressure measurement system, flow measurement system, mode switching system and cleaning system, including: The pressure measurement system is connected to the handle (2) at one end and to the flow measurement system at the other end, and is used to measure the exhaled air pressure; the handle (2) is connected to the mouthpiece (1); The flow measurement system is connected to the pressure measurement system at one end and to the gas switching system at the other end for measuring the exhaled gas flow; The mode switching system has one end connected to the flow measurement system and the other end connected to the cleaning system, and is used to switch the working mode of the exhaled breath online sampling device to the detection mode or the cleaning mode; The cleaning system is connected to the mode switching system and is used for reverse cleaning of the exhaled breath online sampling device.

2. The multifunctional exhaled breath online sampling device according to claim 1, characterized in that: The pressure measurement system comprises: a sensor frame (3), a saliva chamber (5) and a pressure sensor (18), wherein: The sensor frame (3) is a hollow structure, connected to the mouthpiece (1) through the handle (2), a saliva tank (5) is arranged below the sensor frame (3), a pressure sensor (18) is arranged above the sensor frame (3), and a high-pressure detection port (17) is arranged at the rear end of the sensor frame (3); A sealing screw (4) is provided below the saliva chamber (5). When the exhaled air online sampling device is in a cleaning mode, the sealing screw (4) is removed to clean the saliva chamber (5).

3. The multifunctional exhaled breath online sampling device according to claim 1, characterized in that: The flow measurement system comprises: an air resistance pipeline (6), a flow sensor (16), a high pressure detection port (17) and a low pressure detection port (15), wherein: The air blocking pipeline (6) is connected to the sensor frame (3), blocking the exhaled air passage, and driving the exhaled air to pass through the high-pressure detection port (17) into the flow sensor (16); the flow sensor (16) is a differential pressure flow sensor, one end of which is connected to the high-pressure detection port (17) and the other end of which is connected to the low-pressure detection port (15).

4. The multifunctional exhaled breath online sampling device according to claim 1, characterized in that: The mode switching system comprises: an electromagnetic valve frame (7), a sampling port (9), an exhaust port (10) and a two-position three-way electromagnetic valve (14), wherein: The solenoid valve frame (7) is a hollow structure. The front end of the solenoid valve frame (7) is connected to a low-pressure detection port (15). The two-position three-way solenoid valve (14) is arranged inside the solenoid valve frame (7). The two-position three-way solenoid valve (14) includes two passages, NO and NC. In a detection mode, NO is closed, NC is opened, and connected to a sampling port (9). In a cleaning mode, NC is closed, NO is opened, and connected to an exhaust port (10). During online collection, the sampling port (9) is connected to the analysis instrument (8b) to directly analyze the exhaled air online; during offline collection, the sampling port (9) is connected to the sample container (8a) to sample and collect the exhaled air.

5. The multifunctional exhaled breath online sampling device according to claim 1, characterized in that: The cleaning system comprises: a three-way pipeline (11), a cleaning pump (13) and a normally open two-way electromagnetic valve (12), wherein: The three ports of the three-way pipe (11) are respectively connected to the exhaust port (10), the cleaning pump (13) and the normally open two-way solenoid valve (12); before sampling, the exhaled breath online sampling device empties the gas in the exhaled breath online sampling device through the normally open two-way solenoid valve (12); The cleaning pump (13) is used to, in a cleaning mode, allow high-pressure gas to flow from the cleaning system through a mode switching system, a flow measurement system, a pressure measurement system, and a handle (2) in sequence, and to be blown out from the mouthpiece (1) to complete cleaning.

6. The multifunctional exhaled breath online sampling device according to claim 1, characterized in that: The exhaled breath online sampling device also includes a screen and a control system, which can display the measurement results of the pressure sensor (18) and the flow sensor (16) in real time, and can display the online analysis results of the analysis instrument (8b) in real time during online collection.

7. A multifunctional exhaled breath online sampling method implemented based on the multifunctional exhaled breath online sampling device according to any of claims 1 to 6, characterized in that: include: Before sampling, the NC of the two-position three-way solenoid valve (14) is closed and the NO is opened, and the gas in the exhaled breath online sampling device is emptied through the normally open two-way solenoid valve (12); then the NO of the two-position three-way solenoid valve (14) is closed and the NC is opened; Blow air into the exhaled air online sampling device through the mouthpiece (1), the exhaled air flows through the pressure sensor (18), the exhaled air pressure is measured, and saliva is collected in the saliva chamber (5); The exhaled air flows from the high pressure detection port (17) to the low pressure detection port (15), and the exhaled air flow rate is measured by the flow sensor (16); The exhaled air flows from the low pressure detection port (15) to the electromagnetic valve frame (7), and flows through the sampling port (9) through the passage NO, and is collected by the sample container (8a) or analyzed online by the analytical instrument (8b); The exhaled air pressure, exhaled air flow and the results of the online analysis are displayed via a screen and a control system (19).

8. The multifunctional exhaled breath online sampling method according to claim 1, characterized in that: The working method of the exhaled air online sampling device in the cleaning mode is as follows: The NC of the two-position three-way solenoid valve (14) is closed, the NO is opened, the normally open two-way solenoid valve (12) is closed, and the cleaning pump (13) is turned on to allow the high-pressure gas to flow from the cleaning system through the mode switching system, the flow measurement system, the pressure measurement system, the handle (2) in sequence, and blown out from the mouthpiece (1) to complete the cleaning.

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