A sampling device for real-time continuous analysis of end-tidal breath

Abstract

The application relates to a sampling device, in particular to a sampling device for real-time continuous analysis of end-exhaled air. The sampling device comprises first to fourth three-way valves, a first sampling ring, a second sampling ring, an air suction pump, a purge gas pipeline, an exhaled air pipeline, a carbon dioxide sensor and an analysis detector; the air inlets of the first sampling ring and the second sampling ring are connected with the purge gas pipeline through the first three-way valve and connected with the exhaled air pipeline provided with the carbon dioxide sensor through the second three-way valve; the air outlets of the first sampling ring and the second sampling ring are connected with the analysis detector through the third three-way valve and connected with the air suction pump through the fourth three-way valve; through linkage switching of the first to fourth three-way valves, the first sampling ring and the second sampling ring alternately carry out sampling and sampling, real-time accurate sampling of end-exhaled air in each breathing cycle and continuous sampling analysis are realized. The application has high time resolution, accurate end-exhaled air sampling and constant volume, and good consistency of detection results.

Description

TECHNICAL FIELD

[0001] The present application relates to a sampling device, in particular to a sampling device for real-time continuous analysis of end-expiratory gas. BACKGROUND

[0002] Small volatile molecules such as ammonia, acetone, acetonitrile, hydrogen cyanide, and nitric oxide in exhaled breath are closely related to human diseases. For example, exhaled nitric oxide detection has become the gold standard for diagnosing childhood asthma. Therefore, exhaled breath detection as a large sample size, non-invasive disease screening method has important applications in the field of clinical medicine. In recent years, by measuring the concentration of trace propofol and other anesthetics in exhaled breath, bedside real-time monitoring of the anesthesia status of patients in the operating room or intensive care unit has become a new hot direction of clinical research.

[0003] The humidity of exhaled breath is close to 100% RH, there are many high-concentration interferents such as ketones, aldehydes, and inhaled anesthetics, and only end-expiratory gas (alveolar gas) can truly reflect the blood concentration of propofol and other intravenous anesthetics. These have brought great challenges to the real-time, continuous monitoring of trace propofol and other intravenous anesthetics in exhaled breath.

[0004] IMS is based on the difference of ion mobility K0 in atmospheric pressure electric field to realize the separation, detection and identification of target substances, which has the advantages of high sensitivity (pptv level), rapidity (single spectrum analysis <20 ms), portability, etc. and is suitable for the development of bed-side continuous and real-time monitoring instruments. However, the IMS detection is easily affected by the high humidity of exhaled breath. Perl et al. (Brit J Anaesth, 2009, 103:822) combined IMS with pre-separation of bundle capillary (MCC) to directly measure propofol in the patient's end exhaled breath and test its correlation with the blood concentration of propofol, with a sampling interval of about 1 minute. Based on MCC-IMS, a commercial bed-side exhaled breath monitor EDMON has also appeared, but the quantitative results are seriously affected by the humidity of exhaled breath, and the clinical practicability needs to be discussed. In order to solve the influence of high humidity, Zhou Qinghua et al. (Talanta, 2012, 98:241) combined IMS with membrane sampling to realize the sensitive measurement of exhaled breath propofol in stable intravenous anesthesia, with a detection limit as low as 65 pptv, but it needs long time sampling enrichment (1-3 minutes) and cannot distinguish the end exhaled breath propofol concentration. Therefore, Jiang Dandan et al. (Anal Chem, 2018, 90:5280) developed a dynamic purge sampling technology to eliminate the influence of humidity when IMS directly samples exhaled breath. The single analysis period of this method is about 30 s, which cannot realize real-time continuous sampling analysis of the end exhaled breath of each breathing cycle. Further, Jiang Dandan et al. (Anal Chim Acta, 2021, 1150:338223) developed a sample dilution sampling technology in the ion source to realize the direct sampling real-time continuous analysis of exhaled breath, which can quickly track the change curve of propofol in each breathing cycle, and the quantitative range is 0.2-40 ppbv. However, the detection results of this method are greatly affected by the sampling process, and the consistency of the results is insufficient. SUMMARY

[0005] In view of the above problems, the purpose of the present application is to provide a sampling device for real-time continuous analysis of end exhaled breath, to solve the problem of the detection results of the existing sampling device being greatly affected by the sampling process and the consistency of the results being insufficient.

[0006] In order to achieve the above purpose, the technical scheme adopted by the present application is:

[0007] The present application provides a sampling device for real-time continuous analysis of end exhaled breath, comprising a first three-way valve, a second three-way valve, a third three-way valve, a fourth three-way valve, a first sampling ring, a second sampling ring, a gas suction pump, a purge gas pipeline, an exhaled breath pipeline, a carbon dioxide sensor and an analysis and detection instrument.

[0008] The purge gas pipeline is connected with the gas inlet of the first sampling ring and the second sampling ring through the first three-way valve, and the purge gas pipeline is used to provide purge gas.

[0009] The exhalation gas pipeline is connected with the gas inlet of the first sampling ring and the second sampling ring through the second three-way valve, and the carbon dioxide sensor is arranged on the purge gas pipeline, the exhalation gas pipeline is used for providing exhalation gas, and the carbon dioxide sensor is used for detecting the content of carbon dioxide in the exhalation gas;

[0010] The analysis detector is connected with the gas outlets of the first sampling ring and the second sampling ring through the third three-way valve, and the analysis detector is used for sampling analysis and detection of the end exhalation gas contained in the first sampling ring or the second sampling ring.

[0011] The air pump is connected with the gas outlets of the first sampling ring and the second sampling ring through the fourth three-way valve, and the air pump is used for sampling of the exhalation gas of the first sampling ring and the second sampling ring.

[0012] Through linkage switching of the first three-way valve, the second three-way valve, the third three-way valve and the fourth three-way valve, the first sampling ring and the second sampling ring work in parallel, and sampling and sampling are alternately performed, so that real-time and accurate sampling and continuous sampling analysis of the end exhalation gas in each breathing cycle are realized.

[0013] The purge gas is purified air or high-purity nitrogen.

[0014] The exhalation gas is the exhalation gas of a patient in an operating room or an intensive care unit.

[0015] The material of the first sampling ring and the second sampling ring is polyether ether ketone or polytetrafluoroethylene.

[0016] The sampling volume of the first sampling ring and the second sampling ring is 0.5-5 milliliters.

[0017] The analysis detector is a mass spectrometer or an ion mobility spectrometer.

[0018] The working process of the sampling device for real-time continuous analysis of end exhalation gas includes the following steps:

[0019] Step S1: The purge gas pipeline is connected with the gas inlet of the first three-way valve, the gas outlet of the first three-way valve is connected with the gas inlet of the first sampling ring, the gas outlet of the first sampling ring is connected with the gas inlet of the third three-way valve, the gas outlet of the third three-way valve is connected with the sample gas inlet of the analysis detector through a gas pipeline, and the gas in the first sampling ring is carried by the purge gas to enter the analysis detector through the sample gas inlet for analysis and detection; the exhalation gas pipeline is connected with the gas inlet of the second three-way valve in series with the carbon dioxide sensor, the gas outlet of the second three-way valve is connected with the gas inlet of the second sampling ring, the gas outlet of the second sampling ring is connected with the gas inlet of the fourth three-way valve, the gas outlet of the fourth three-way valve is connected with the air pump through a gas pipeline, and the exhalation gas flows through the second sampling ring and is then pumped away by the air pump.

[0020] Step S2: the gas outlet of the first three-way valve is switched to communicate with the gas inlet of the second sampling ring, the gas outlet of the second sampling ring is switched to communicate with the gas inlet of the third three-way valve, and the end-exhaled gas in the second sampling ring is carried by the purge gas to enter the analysis detector through the sample gas inlet for analysis and detection; the gas outlet of the second three-way valve is switched to communicate with the gas inlet of the first sampling ring, the gas outlet of the first sampling ring is switched to communicate with the gas inlet of the fourth three-way valve, and the exhaled gas flows through the first sampling ring and is then pumped away by the air pump;

[0021] Steps S1 and S2 are cyclically executed.

[0022] When the carbon dioxide sensor detects that the carbon dioxide partial pressure value in the exhaled gas rapidly increases and the increasing rate decreases to 1 mmHg / s each time, steps S1 and S2 are executed.

[0023] The sampling device for real-time continuous analysis of end-exhaled gas provided by the application has the advantages that: the sampling device is internally provided with four three-way valves for switching of gas flow paths and two sampling rings for quantitative sampling of exhaled gas, through coordinated switching between the three-way valves, exhaled gas sampling channels and exhaled gas sample introduction analysis channels that work in parallel and have alternating states are constructed, and further combined with real-time monitoring of the carbon dioxide sensor on the carbon dioxide partial pressure value in the exhaled gas, real-time accurate sampling and continuous sample introduction analysis of end-exhaled gas in each breathing cycle are realized. The sampling device has high time resolution, accurately samples end-exhaled gas with constant volume, has good consistency of detection results, and at the same time, maintains the rapid pre-separation function of the sampling ring for sample introduction, and can eliminate the influence of high humidity water vapor in the end-exhaled gas on detection of trace propofol and other target substances. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 FIG. 1 is a structural diagram of the sampling device for real-time continuous analysis of end-exhaled gas of the application;

[0025] 1, first three-way valve; 2, second three-way valve; 3, third three-way valve; 4, fourth three-way valve; 5, first sampling ring; 6, second sampling ring; 7, sample gas inlet; 8, air pump; 9, purge gas pipeline; 10, exhaled gas pipeline; 11, carbon dioxide sensor; 12, photoionization source; 13, ionization zone; 14, ion gate; 15, ion migration zone; 16, ion detection electrode; 17, gas outlet; 18, drift gas inlet.

[0026] Figure 2 FIG. 2 is a working timing diagram of the sampling device for real-time continuous analysis of end-exhaled gas of the application.

[0027] Figure 3A result curve diagram of the sampling device for real-time continuous analysis of end-expiratory gas combined with ion mobility spectrometry for real-time continuous monitoring of trace propofol in the exhaled gas of a patient during surgery. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be described in detail below with reference to the drawings and specific embodiments.

[0029] Referring to Figure 1 As shown in the drawings, the present application provides a sampling device for real-time continuous analysis of end-expiratory gas, which comprises a first three-way valve 1, a second three-way valve 2, a third three-way valve 3, a fourth three-way valve 4, a first sampling ring 5, a second sampling ring 6, a gas suction pump 8, a purge gas pipeline 9, an exhaled gas pipeline 10, a carbon dioxide sensor 11 and an analysis detector; wherein the purge gas pipeline 9 is connected with the gas inlets of the first sampling ring 5 and the second sampling ring 6 through the first three-way valve 1, and the purge gas pipeline 9 is used to provide purge gas; the exhaled gas pipeline 10 is connected with the gas inlets of the first sampling ring 5 and the second sampling ring 6 through the second three-way valve 2, the carbon dioxide sensor 11 is arranged on the purge gas pipeline 9, the exhaled gas pipeline 10 is used to provide exhaled gas, and the carbon dioxide sensor 11 is used to detect the content of carbon dioxide in the exhaled gas; the analysis detector is connected with the gas outlets of the first sampling ring 5 and the second sampling ring 6 through the third three-way valve 3, and the analysis detector is used to sample and analyze the end-expiratory gas contained in the first sampling ring 5 or the second sampling ring 6; the gas suction pump 8 is connected with the gas outlets of the first sampling ring 5 and the second sampling ring 6 through the fourth three-way valve 4, and the gas suction pump 8 is used for sampling the exhaled gas of the first sampling ring 5 and the second sampling ring 6; through the linkage switching of the first three-way valve 1, the second three-way valve 2, the third three-way valve 3 and the fourth three-way valve 4, the first sampling ring 5 and the second sampling ring 6 work in parallel, and sampling and sampling are alternately performed, so that real-time and accurate sampling and continuous sampling analysis of the end-expiratory gas in each breathing cycle are realized.

[0030] In the embodiments of the present application, the purge gas is purified air filtered by water-removing silica gel, activated carbon and molecular sieve, or high-purity nitrogen filtered by silica gel, activated carbon and molecular sieve; and the exhaled gas is the exhaled gas of a patient in an operating room or an intensive care unit.

[0031] Specifically, the material of the first sampling ring 5 and the second sampling ring 6 is polyether ether ketone or polytetrafluoroethylene. The sampling volume of the first sampling ring 5 and the second sampling ring 6 is 0.5-5 milliliters, and the optimal sampling volume is 2.5 milliliters. The analysis detector is a mass spectrometer or an ion mobility spectrometer.

[0032] The present application provides a sampling device for real-time continuous analysis of end-expiratory gas, and the working process thereof comprises the following steps:

[0033] Step S1: the purge gas pipeline 9 is connected with the gas inlet of the first three-way valve 1, the gas outlet of the first three-way valve 1 is connected with the gas inlet of the first sampling ring 5, the gas outlet of the first sampling ring 5 is connected with the gas inlet of the third three-way valve 3, the gas outlet of the third three-way valve 3 is connected with the sample gas inlet 7 of the analysis detector through a gas pipeline, and the gas in the first sampling ring 5 is carried by the purge gas to enter the analysis detector through the sample gas inlet 7 to be analyzed, so that the sampling and analysis of the first sampling ring 5 are realized; at the same time, the exhaled gas pipeline 10 is connected with the carbon dioxide sensor 11 in series, and then connected with the gas inlet of the second three-way valve 2, the gas outlet of the second three-way valve 2 is connected with the gas inlet of the second sampling ring 6, the gas outlet of the second sampling ring 6 is connected with the gas inlet of the fourth three-way valve 4, and the gas outlet of the fourth three-way valve 4 is connected with the air pump 8 through a gas pipeline, so that the exhaled gas flows through the second sampling ring 6 and is then pumped away by the air pump 8, thereby realizing the sampling of the second sampling ring 6.

[0034] Step S2: the gas outlet of the first three-way valve 1 is switched to be connected with the gas inlet of the second sampling ring 6, the gas outlet of the second sampling ring 6 is switched to be connected with the gas inlet of the third three-way valve 3, the end exhaled gas in the second sampling ring 6 is carried by the purge gas to enter the analysis detector through the sample gas inlet 7 to be analyzed, so that the sampling and analysis of the second sampling ring 6 are realized; at the same time, the gas outlet of the second three-way valve 2 is switched to be connected with the gas inlet of the first sampling ring 5, the gas outlet of the first sampling ring 5 is switched to be connected with the gas inlet of the fourth three-way valve 4, the exhaled gas flows through the first sampling ring 5 and is then pumped away by the air pump 8, thereby realizing the sampling of the first sampling ring 5.

[0035] Steps S1 and S2 are cyclically executed.

[0036] Specifically, when the carbon dioxide sensor 11 detects that the carbon dioxide partial pressure value in the exhaled gas rapidly rises and the rising rate decreases to 1 mmHg / s each time, steps S1 and S2 are executed.

[0037] Embodiment one

[0038] The sampling device disclosed in the application is used in combination with ion mobility spectrum, such as Figure 1The first three-way valve 1, the second three-way valve 2, the third three-way valve 3 and the fourth three-way valve 4 in the sampling device are all MTV-3R-NM6F electromagnetic valves of Takasago Electric Co., Ltd., the first sampling ring 5 and the second sampling ring 6 are both made of polytetrafluoroethylene pipes with an inner diameter of 1.5 mm and an outer diameter of 3.0 mm, and the sampling volume of each of the first sampling ring 5 and the second sampling ring 6 is 2.5 mL, the carbon dioxide sensor 11 is a SCD30 carbon dioxide module of SENSIRION Co., Ltd. in Switzerland, and the air pump 8 is an NMP830 diaphragm pump of KNF Co.

[0039] The working time sequence of the sampling device when used for real-time online analysis of end-exhaled gas is shown in FIG. 2. Figure 2 In the working time sequence, the first sampling ring 5 and the second sampling ring 6 work in parallel, and the working state is switched between the sampling state and the sample injection state, and the switching time is consistent with the time when each carbon dioxide partial pressure extreme value is monitored by the carbon dioxide sensor.

[0040] In the initial state, at t=0, the purge gas flows through the first three-way valve 1, the first sampling ring 5 and the third three-way valve 3 in sequence, and then enters the ion mobility spectrometer through the sample gas inlet 7, and the exhaled gas flows through the carbon dioxide sensor 11, the second three-way valve 2, the second sampling ring 6 and the fourth three-way valve 4 in sequence, and then is pumped away by the air pump 8.

[0041] When the carbon dioxide sensor 11 first monitors that the carbon dioxide partial pressure value in the exhaled gas rapidly increases and the increasing rate decreases to 1 mmHg / s, the outlet of the first three-way valve 1 is switched to be connected to the inlet of the second sampling ring 6, the outlet of the second sampling ring 6 is switched to be connected to the inlet of the third three-way valve 3, the end-exhaled gas in the second sampling ring 6 is carried by the purge gas to enter the ion mobility spectrometer through the sample gas inlet 7 for analysis and detection, at the same time, the outlet of the second three-way valve 2 is switched to be connected to the inlet of the first sampling ring 5, and the outlet of the first sampling ring 5 is switched to be connected to the inlet of the fourth three-way valve 4, and the exhaled gas is pumped away by the air pump 8 after flowing through the first sampling ring 5.

[0042] When the carbon dioxide sensor 11 detects a rapid increase in the partial pressure of carbon dioxide in the exhaled air for the second time, and the rate of increase decreases to 1 mmHg per second, the outlet of the first three-way valve 1 switches to connect with the inlet of the first sampling ring 5, and the outlet of the first sampling ring 5 switches to connect with the inlet of the third three-way valve 3. The exhaled air at the end of the first sampling ring 5 is carried by the purge gas carrier and enters the ion mobility spectrometer for analysis and detection through the sample gas inlet 7. The outlet of the second three-way valve 2 switches to connect with the inlet of the second sampling ring 6, and the outlet of the second sampling ring 6 switches to connect with the inlet of the fourth three-way valve 4. The exhaled airflow is drawn away by the suction pump 8 after passing through the second sampling ring 6.

[0043] When the carbon dioxide sensor 11 detects a rapid increase in the partial pressure of carbon dioxide in the exhaled air for the third time, and the rate of increase decreases to 1 mmHg per second, the outlet of the first three-way valve 1 switches to connect with the inlet of the second sampling ring 6, and the outlet of the second sampling ring 6 switches to connect with the inlet of the third three-way valve 3. The exhaled air at the end of the second sampling ring 6 is carried by the purge gas carrier and enters the ion mobility spectrometer for analysis and detection through the sample gas inlet 7. At the same time, the outlet of the second three-way valve 2 switches to connect with the inlet of the first sampling ring 5, and the outlet of the first sampling ring 5 switches to connect with the inlet of the fourth three-way valve 4. The exhaled airflow is drawn away by the suction pump 8 after passing through the first sampling ring 5.

[0044] The above process is executed cyclically. Through the linkage switching of the first three-way valve 1, the second three-way valve 2, the third three-way valve 3 and the fourth three-way valve 4, the first sampling ring 5 and the second sampling ring 6 work in parallel and sample alternately to achieve real-time accurate sampling and continuous sample analysis of the exhaled air at the end of each respiratory cycle until the exhaled air monitoring ends.

[0045] Example 2

[0046] Based on the sampling device and its operating mode for real-time online analysis of terminal exhaled breath disclosed in Example 1, the purge gas flow rate was set to 200 mL / min, the drift gas flow rate to 300 mL / min, and the pumping speed of the suction pump 8 to 100 mL / min. The ion gate opening time of the ion mobility spectrometer was set to 50 μs, and the electric field strength in the ionization and migration regions was set to 500 V / cm. Real-time continuous sampling and analysis of trace amounts of propofol in the patient's exhaled breath during surgery was performed. The results are as follows: Figure 3 As shown. In Figure 3 During the continuous respiratory cycle shown, the concentration of propofol in exhaled air can be observed to exhibit periodic changes within the range of 4-10 ppbv.

[0047] The application discloses a sampling device for real-time continuous analysis of end-expiratory gas, which is provided with four three-way valves for airflow passage switching and two sampling rings for quantitative sampling of exhaled gas. Through the coordinated switching among the three-way valves, the exhaled gas sampling channel and the exhaled gas sampling and analysis channel working in parallel and alternately changing are constructed. Further combined with the real-time monitoring of the carbon dioxide partial pressure value in the exhaled gas by the carbon dioxide sensor, the real-time accurate sampling and continuous sampling and analysis of the end-expiratory gas in each breathing cycle are realized. The sampling device has high time resolution, accurate end-expiratory gas sampling and constant volume, good consistency of detection results, and the function of rapid pre-separation of the sampling ring is maintained, so that the influence of high humidity water vapor in the end-expiratory gas on the detection of trace propofol and other target substances can be eliminated.

[0048] The above merely describes the embodiments of the application, and is not used to limit the protection scope of the application. Any modification, equivalent replacement, improvement, expansion and the like made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A sampling device for real-time continuous analysis of end-tidal breath, characterized in that, The device comprises a first three-way valve (1), a second three-way valve (2), a third three-way valve (3), a fourth three-way valve (4), a first sampling ring (5), a second sampling ring (6), a gas suction pump (8), a purge gas pipeline (9), an exhaled gas pipeline (10), a carbon dioxide sensor (11) and an analysis detector. The purge gas pipeline (9) is connected to the gas inlets of the first sampling ring (5) and the second sampling ring (6) through the first three-way valve (1), and the purge gas pipeline (9) is used for providing purge gas. The exhaled gas pipeline (10) is connected to the gas inlets of the first sampling ring (5) and the second sampling ring (6) through the second three-way valve (2), the carbon dioxide sensor (11) is arranged on the purge gas pipeline (9), the exhaled gas pipeline (10) is used for providing exhaled gas, and the carbon dioxide sensor (11) is used for detecting the content of carbon dioxide in the exhaled gas. The analysis detector is connected to the gas outlets of the first sampling ring (5) and the second sampling ring (6) through the third three-way valve (3), and the analysis detector is used for sampling analysis and detection of end exhaled gas contained in the first sampling ring (5) or the second sampling ring (6). The gas suction pump (8) is connected to the gas outlets of the first sampling ring (5) and the second sampling ring (6) through the fourth three-way valve (4), and the gas suction pump (8) is used for sampling exhaled gas of the first sampling ring (5) and the second sampling ring (6). Through linkage switching of the first three-way valve (1), the second three-way valve (2), the third three-way valve (3) and the fourth three-way valve (4), the first sampling ring (5) and the second sampling ring (6) work in parallel, and sampling and sampling are alternately performed, so that real-time and accurate sampling and continuous sampling analysis of end exhaled gas in each breathing cycle are realized. The working process of the device comprises the following steps: Step S1: The purge gas pipeline (9) is connected to the gas inlet of the first three-way valve (1), the gas outlet of the first three-way valve (1) is connected to the gas inlet of the first sampling ring (5), the gas outlet of the first sampling ring (5) is connected to the gas inlet of the third three-way valve (3), the gas outlet of the third three-way valve (3) is connected to the sample gas inlet (7) of the analysis detector through a gas pipeline, and the gas in the first sampling ring (5) is carried by the purge gas to enter the analysis detector through the sample gas inlet (7) for analysis and detection; the exhaled gas pipeline (10) is connected to the gas inlet of the second three-way valve (2) after being connected to the carbon dioxide sensor (11) in series, the gas outlet of the second three-way valve (2) is connected to the gas inlet of the second sampling ring (6), the gas outlet of the second sampling ring (6) is connected to the gas inlet of the fourth three-way valve (4), the gas outlet of the fourth three-way valve (4) is connected to the gas suction pump (8) through a gas pipeline, and the exhaled gas flows through the second sampling ring (6) and is then sucked away by the gas suction pump (8). Step S2: the gas outlet of the first three-way valve (1) is switched to communicate with the gas inlet of the second sampling ring (6), the gas outlet of the second sampling ring (6) is switched to communicate with the gas inlet of the third three-way valve (3), and the end-expired breath in the second sampling ring (6) is carried by the purge gas to enter the analysis detector through the sample gas inlet (7) for analysis and detection; the gas outlet of the second three-way valve (2) is switched to communicate with the gas inlet of the first sampling ring (5), the gas outlet of the first sampling ring (5) is switched to communicate with the gas inlet of the fourth three-way valve (4), and the breath flows through the first sampling ring (5) and is then pumped away by the air pump (8); Steps S1 and S2 are cyclically executed.

2. The sampling device for real-time continuous analysis of exhaled breath at the end- of- take according to claim 1, characterized in that, The purge gas is purified air or high-purity nitrogen.

3. The sampling device for real-time continuous analysis of exhaled breath at the end- of- take according to claim 1, characterized in that, The breath is the exhaled gas of a patient in an operating room or an intensive care unit.

4. The sampling device for real-time continuous analysis of exhaled breath at the end- of- take according to claim 1, characterized in that, The materials of the first sampling ring (5) and the second sampling ring (6) are polyether ether ketone or polytetrafluoroethylene.

5. The sampling device for real-time continuous analysis of exhaled breath at the end- of- take according to claim 1, characterized in that, The sampling volumes of the first sampling ring (5) and the second sampling ring (6) are 0.5-5 milliliters.

6. The sampling device for real-time continuous analysis of exhaled breath at the end- tidal according to claim 1, characterized in that, The analysis detector is a mass spectrometer or an ion mobility spectrometer.

7. The sampling device for real-time continuous analysis of exhaled breath at the end- of- take according to claim 1, characterized in that, Steps S1 and S2 are executed when the carbon dioxide sensor (11) detects that the carbon dioxide partial pressure value in the breath rapidly increases and the increasing rate decreases to 1 mmHg / s each time.

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