A method and apparatus for exhalation detection

Abstract

The application provides an exhalation detection method and device, the method comprising: setting a test flow rate and a test time period of a gas mass flow meter; extracting background gas and a pre-collected exhalation sample to be detected by a micro vacuum pump, and inputting the background gas and the pre-collected exhalation sample to be detected into a sample inlet after drying treatment and flow rate control; in a baseline stabilization time period, closing a three-way valve, opening a background gas channel, and detecting a first change curve of the resistance of a gas detection array; in a response test time period, opening the three-way valve, opening an exhalation sample channel to be detected, closing the background gas channel, and detecting a second change curve of the resistance; in a baseline recovery time period, closing the three-way valve, opening the background gas channel, and detecting a third change curve of the resistance; determining an exhalation curve of the exhalation sample to be detected based on the first, second, and third change curves; and determining the health status of an individual corresponding to different exhalation samples to be detected based on different exhalation curves.

Description

Technical Field

[0001] This invention belongs to the field of gas sensors, and more specifically, relates to a breath detection method and device. Background Technology

[0002] The types and concentrations of exhaled gases reflect a person's health status to some extent. Breath diagnosis, by detecting changes in the types or concentrations of exhaled gases, reflects the metabolic state of corresponding tissue cells and has great potential in medical diagnosis and treatment monitoring. It is suitable for developing a non-invasive and convenient auxiliary diagnostic method for diseases.

[0003] In related technologies, breath testing mainly employs three methods: First, spectroscopic detection methods based on gas chromatography-mass spectrometry (GC-MS), such as the medical breath testing device and method described in patent CN201310092319.7, which combines chromatographic column and surface acoustic wave detector analysis for data processing. Second, detection methods based on laser spectroscopy. Third, sensor-based detection methods, such as the composite breath testing device described in patent CN201721650734.X, primarily used for routine clinical detection of methane and hydrogen in exhaled breath; and a breath testing device in patent CN201921371901.6, which uses a gas sensor based on TiO2 nanomaterials to quantitatively analyze the concentrations of common human exhaled gases, including acetone and ammonia, primarily used for auxiliary reference information on the risk of diseases such as diabetes and chronic renal failure. In comparison, while the first two methods offer high accuracy and sensitivity, they are often only suitable for detecting single components and are expensive. The third sensor-based method is relatively easy to operate and low-cost.

[0004] However, the relevant technologies still have the following problems: (1) During online detection, different individuals may have different exhalation flow rates, making it difficult for the gas detection array to complete the detection of the gas to be tested under stable pressure; (2) There is no standardized procedure for detection, resulting in problems such as difficulty in reproducibility, and it is often applicable to the detection of specific diseases and is not universal; (3) Some methods involve sample pretreatment, which requires concentration and the device structure is complex, often requiring professional personnel to operate; (4) Some methods require additional carrier gas cylinders, which increases the size and complexity of the device. Summary of the Invention

[0005] To address the aforementioned deficiencies in related technologies, this invention provides a breath detection method and apparatus.

[0006] In a first aspect, the present invention provides a breath detection method, comprising:

[0007] Set the gas test flow rate and test time period for the gas mass flow meter, wherein the test time period includes the baseline stabilization time period, the response test time period, and the baseline recovery time period;

[0008] Background gas and pre-collected breath samples are extracted using a miniature vacuum pump, dried, and then fed into the background gas inlet and the test gas inlet respectively after the flow rate is controlled by the gas mass flow meter.

[0009] During the baseline stabilization period, the three-way solenoid valve is set to be closed, the gas path of the gas to be tested is closed, the background gas path is opened, and the first change curve of the resistance of the gas detection array is detected.

[0010] During the response test period, the three-way solenoid valve is switched to the open state, the gas path to be tested is opened, the background gas path is closed, and the second change curve of the resistance of the gas detection array is detected.

[0011] During the baseline recovery period, the three-way solenoid valve is switched to the closed state, the gas path to be tested is closed, the background gas path is opened, and the third change curve of the resistance of the gas detection array is detected.

[0012] Based on the first change curve, the second change curve, and the third change curve, the exhalation curve of the exhalation sample to be tested is determined;

[0013] Based on the exhalation curves of different test exhalation samples, the health status of individuals corresponding to different test exhalation samples is determined.

[0014] In some embodiments, determining the health status of individuals corresponding to different breath samples based on their exhalation curves includes:

[0015] The expiratory curves of different test expiratory samples were analyzed using the Fisher linear discriminant function to obtain classification results;

[0016] Based on the classification results, the health status of the individual corresponding to the breath sample to be tested is determined.

[0017] In some embodiments, when the different breath samples to be tested are breath samples from different individuals within the same time period, the classification result is used to distinguish the health status of the different individuals; when the breath samples to be tested are breath samples from the same individual within different time periods, the classification result is used to characterize the changes in the health status of the same individual within different time periods.

[0018] In some embodiments, the gas test flow rate and test time period of the gas mass flow meter, as well as the state switching of the three-way solenoid valve, are controlled by a host computer.

[0019] In some embodiments, the first change curve of the resistance of the gas detection array includes:

[0020] The resistance of the gas detection array is measured using the first change curve under the influence of the background gas.

[0021] In some embodiments, the second change curve of the resistance of the gas detection array includes:

[0022] The resistance of the gas detection array is measured using the second change curve under the action of the first mixed gas; the ratio of the background gas and the exhaled breath sample to be tested in the first mixed gas decreases over time until it becomes 0.

[0023] In some embodiments, the third variation curve of the resistance of the gas detection array includes:

[0024] The resistance of the gas detection array is measured under the action of the second mixed gas, and the third change curve is obtained. The ratio of the background gas and the exhaled breath sample to be tested in the second mixed gas increases over time until it becomes 1.

[0025] In a second aspect, the present invention provides a breath detection device, comprising:

[0026] The parameter setting unit is used to set the gas test flow rate and test time period of the gas mass flow meter. The test time period includes the baseline stabilization time period, the response test time period, and the baseline recovery time period.

[0027] The sampling unit is used to extract background gas and pre-collected breath samples to be tested using a micro vacuum pump. After drying and flow rate control by the gas mass flow meter, the samples are respectively input into the background gas inlet and the test gas inlet.

[0028] The baseline detection unit is used to set the three-way solenoid valve to be closed, the gas path of the gas to be tested to be closed, and the background gas path to be open during the baseline stabilization period, and to detect the first change curve of the resistance of the gas detection array.

[0029] The response detection unit is used to switch the three-way solenoid valve to the open state, open the gas path of the gas to be tested, close the background gas path, and detect the second change curve of the resistance of the gas detection array during the response test period.

[0030] The recovery detection unit is used to switch the three-way solenoid valve to the closed state during the recovery baseline time period, close the gas path of the gas to be tested, open the background gas path, and detect the third change curve of the resistance of the gas detection array.

[0031] A data processing unit is used to determine the exhalation curve of the breath sample to be tested based on the first change curve, the second change curve, and the third change curve.

[0032] The data analysis unit is used to determine the health status of individuals corresponding to different breath samples based on their exhalation curves.

[0033] Thirdly, the present invention provides an electronic device comprising: at least one memory for storing a program; and at least one processor for executing the program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to execute the method described in the first aspect or any possible implementation thereof.

[0034] Fourthly, the present invention provides a computer-readable storage medium storing a computer program that, when run on a processor, causes the processor to perform the method described in the first aspect or any possible implementation thereof.

[0035] Fifthly, the present invention provides a computer program product that, when run on a processor, causes the processor to perform the method described in the first aspect or any possible implementation thereof.

[0036] The exhalation detection method and device provided by this invention control and monitor the gas flow rate during the exhalation sample testing process using a gas mass flow meter, avoiding detection errors caused by inconsistent flow rates during exhalation from different individuals in online monitoring. This allows the gas detection array to respond to and detect the gas under stable gas pressure. Gas pretreatment only requires drying and flow rate control by a gas mass flow meter, making operation simple. A miniature vacuum pump extracts background gas and pre-collected exhalation samples, eliminating the need for an additional carrier gas cylinder and effectively reducing the overall size and structural complexity of the exhalation detection system. Two gas channels are provided, and the switching of the state of a three-way solenoid valve is controlled to achieve [the desired gas flow rate]. By switching the gas path, the resistance of the gas detection array changes under the influence of background gas, test gas, and a mixture of the two, thus obtaining the exhalation curve of the test exhalation sample. This ensures consistent setting of all test parameters except for the test exhalation sample itself. The final exhalation curve is only related to the gas type and concentration of the test exhalation sample, thereby enabling the determination of the individual's health status corresponding to the test exhalation sample. This achieves exhalation detection with controllable flow rate, rapid effectiveness, simple operation, low cost, and high universality, providing a basis for early screening and later monitoring of various diseases, and has stronger applicability in primary healthcare institutions and individual users. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 This is a schematic flowchart of the breath detection method provided in an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of the classification results provided in an embodiment of the present invention;

[0040] Figure 3 This is one of the structural schematic diagrams of the breath detection device provided in the embodiments of the present invention;

[0041] Figure 4 This is a second schematic diagram of the structure of the breath detection device provided in the embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the structure of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0044] The terms "first" and "second," etc., used in this article are used to distinguish different objects, not to describe a specific order of objects. For example, "first response message" and "second response message," etc., are used to distinguish different response messages, not to describe a specific order of response messages.

[0045] Figure 1 This is a schematic flowchart of the breath detection method provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the method includes at least the following steps:

[0046] S101. Set the gas test flow rate and test time period of the gas mass flow meter. The test time period includes the baseline stabilization time period, the response test time period, and the baseline recovery time period.

[0047] Specifically, gas mass flow meters can be used to control the test flow rate of gas. High-precision gas mass flow meters can effectively reduce system errors. Setting the gas test flow rate and test time period of the gas mass flow meter can effectively control the gas flow rate and the test time of the exhalation test. The test time period can be divided into a baseline stabilization period, a response test period, and a baseline recovery period, depending on the gas content in the gas chamber. The interval lengths of different time periods can be the same or different, and can be set according to the actual test requirements.

[0048] S102. Background gas and pre-collected breath samples are extracted using a micro vacuum pump, dried, and then fed into the background gas inlet and the test gas inlet respectively after the flow rate is controlled by a gas mass flow meter.

[0049] Specifically, a miniature vacuum pump, acting as a pneumatic component, is used to extract the breath sample to be tested and the background gas, eliminating the need for an additional carrier gas cylinder and effectively reducing the overall size and structural complexity of the breath detection system. Optionally, the background gas is indoor air, serving as a reference for the breath sample to be tested and exhibiting relative stability. The background gas can be obtained according to testing requirements.

[0050] Optionally, the breath sample to be tested can be obtained in advance or in real time. Specifically, the breath of patients or healthy individuals can be collected using a gas sampling bag. The gas sampling bag enables contactless acquisition of the breath sample, and sample collection and testing can be performed independently.

[0051] A miniature vacuum pump extracts the breath sample to be tested and background gas. After drying and flow rate control via a gas mass flow meter, the samples are introduced into the background gas inlet and the test gas inlet, respectively. The gas pretreatment operation is simple; it only requires drying and flow rate control via a gas mass flow meter before being introduced into the inlet.

[0052] It should be noted that the order of S101 and S102 is not limited in this invention. The order of the two can be adjusted or they can be executed simultaneously.

[0053] S103. During the baseline stabilization period, the three-way solenoid valve is set to be closed, the gas path of the gas to be tested is closed, the background gas path is opened, and the first change curve of the resistance of the gas detection array is detected.

[0054] S104. During the response test period, switch the three-way solenoid valve to the open state, open the gas path of the gas to be tested, close the background gas path, and detect the second change curve of the resistance of the gas detection array.

[0055] S105. During the baseline recovery period, switch the three-way solenoid valve to the closed state, close the gas path of the gas to be tested, open the background gas path, and detect the third change curve of the resistance of the gas detection array.

[0056] Specifically, although sensor-based breath detection has difficulty identifying the specific gas components in exhaled breath, an array of multiple sensors combined with a pattern recognition algorithm can achieve the response and identification of the exhaled mixture.

[0057] This invention features two air intake channels, including a gas path for the gas to be tested and a background gas path. The unique air path is achieved by controlling the state switching of a three-way solenoid valve.

[0058] During the baseline stabilization period, the three-way solenoid valve is closed, closing the gas path for the gas to be tested and opening the background gas path, thus detecting the first change curve of the resistance of the gas detection array. As time progresses, the gas chamber gradually fills with background gas, and the concentration of the background gas gradually reaches a constant level due to the control of the flow rate. Under the operation of the background gas, the resistance of the gas detection array gradually reaches a stable state.

[0059] During the response test period, the three-way solenoid valve switches from a closed to an open state. At this time, the gas path for the test gas is open, while the background gas path is closed, and the second change curve of the resistance of the gas detection array is detected. As time progresses, the background gas in the gas chamber is continuously discharged, and the test gas is continuously discharged. The resistance of the gas detection array interacts with the test gas upon contact, changing its electrical characteristics and entering the response phase. The gas chamber gradually fills with the test gas, and the concentration of the test gas gradually reaches a constant due to the control of the flow rate. Similarly, the resistance of the gas detection array gradually stabilizes after changing.

[0060] During the baseline recovery period, the three-way solenoid valve switches from open to closed. At this time, the test gas path is closed, while the background gas path is open, and the resistance of the gas detection array is measured using the third curve. As time progresses, the test gas is continuously expelled from the chamber, and the background gas is continuously introduced. Under the cleansing effect of the background gas, the test gas adsorbed on the surface of the gas detection array is analyzed and desorbed, and the resistance of the gas detection array gradually recovers to the baseline state detected during the baseline stabilization period. At this point, the test of one breath sample is complete, and the breath sample can be replaced for the next breath test.

[0061] S106. Based on the first change curve, the second change curve, and the third change curve, determine the exhalation curve of the exhalation sample to be tested.

[0062] Specifically, during the testing of a single breath sample, the exhalation curve of the test breath sample is obtained by measuring the resistance of the gas detection array during the first change curve during the baseline stabilization period, the second change curve during the response test period, and the third change curve during the baseline recovery period, for subsequent analysis.

[0063] S107. Based on the exhalation curves of different test exhalation samples, determine the health status of individuals corresponding to different test exhalation samples.

[0064] Specifically, by statistically analyzing the exhalation curves of different breath samples, the health status corresponding to different breath samples can be obtained, serving as an aid for early screening and later monitoring of disease disputes.

[0065] The types and concentrations of exhaled gases change depending on whether the person is healthy or unhealthy, resulting in different exhalation curves obtained through the aforementioned steps. Even among individuals in the same unhealthy state, different types of diseases, and different stages of the same disease, can alter the types and concentrations of exhaled gases. Therefore, by collecting exhaled breath samples and obtaining the aforementioned exhalation curves, it is possible to determine an individual's health status.

[0066] The exhalation detection method provided in this invention controls and monitors the gas flow rate during the exhalation sample testing process using a gas mass flow meter, avoiding detection errors caused by inconsistent flow rates among different individuals during online monitoring. This allows the gas detection array to respond to and detect the gas under stable gas pressure. Gas pretreatment only requires drying and flow rate control by a gas mass flow meter, making the operation simple. A miniature vacuum pump extracts background gas and pre-collected exhalation samples, eliminating the need for an additional carrier gas cylinder and effectively reducing the overall size and structural complexity of the exhalation detection system. Two gas channels are provided, and the switching of the three-way solenoid valve is controlled to achieve the desired gas flow. By switching the gas path, the resistance of the gas detection array changes under the influence of background gas, test gas, and a mixture of the two, thus obtaining the exhalation curve of the test exhalation sample. This ensures consistent setting of all test parameters except for the test exhalation sample itself. The final exhalation curve is only related to the gas type and concentration of the test exhalation sample, thereby enabling the determination of the individual's health status corresponding to the test exhalation sample. This achieves exhalation detection with controllable flow rate, rapid effectiveness, simple operation, low cost, and high universality, providing a basis for early screening and later monitoring of various diseases, and has stronger applicability in primary healthcare institutions and individual users.

[0067] In some embodiments, S107 determines the health status of individuals corresponding to different breath samples based on their exhalation curves, specifically including:

[0068] The expiratory curves of different test expiratory samples were analyzed using the Fisher linear discriminant function to obtain classification results;

[0069] Based on the classification results, the health status of the individual corresponding to the breath sample to be tested is determined.

[0070] Specifically, discriminant analysis can be used to determine the type attributes of various feature values ​​of variables in the data. In this invention, the data processing tool can be a Fisher linear discriminant. Fisher linear discriminant analysis can effectively distinguish different individuals and does not impose any requirements on the overall data distribution, making it effective when dealing with a large number of features or unknown categories.

[0071] By performing linear discriminant analysis on the exhalation curves of different test exhalation samples, a classification result is obtained. Based on the classification result, the health status of the individual corresponding to the test exhalation sample is determined.

[0072] Optionally, when different breath samples to be tested are breath samples from different individuals within the same time period, the classification results are used to distinguish the health status of different individuals. For example, if the different breath samples to be tested include breath samples from healthy people and people with diseases, the Fisher linear discriminant can effectively distinguish between the two groups. As another example, if the different breath samples to be tested include breath samples from different categories of people with diseases, such as uremia patients and lung cancer patients, the Fisher linear discriminant can effectively distinguish between the two groups.

[0073] Optionally, when different breath samples are from the same individual at different time periods, the classification results are used to characterize changes in the individual's health status over different time periods. For example, if different breath samples are from the same individual in a diseased state and a state of recovery, the Fisher linear discriminant can effectively distinguish between breath samples in different states. As another example, if different breath samples are from the same individual at different stages of a disease, such as early, middle, and late-stage lung cancer, the Fisher linear discriminant can effectively distinguish between breath samples at different stages.

[0074] It can be seen that the exhalation detection method provided by the present invention is not limited to the diagnosis of a certain disease or a certain type of disease.

[0075] In some embodiments, the gas test flow rate and test time period of the gas mass flow meter, as well as the state switching of the three-way solenoid valve, are controlled by a host computer. Specifically, the gas test speed and test time period of the gas mass flow meter can be set by the host computer, which can also monitor the gas test speed displayed by the gas mass flow meter. The state switching of the three-way solenoid valve can also be precisely controlled by the host computer at timed intervals.

[0076] In some embodiments, the first change curve of the resistance of the gas detection array in S103 specifically includes:

[0077] The first curve showing the change in resistance of the gas detection array under the influence of background gas.

[0078] Specifically, during the baseline phase, the background gas path is open, the test gas path is closed, and background gas is gradually discharged into the gas chamber. As the background gas is discharged at a uniform rate, the resistance change of the gas detection array gradually stabilizes. This demonstrates that the gas test flow rate and test time period cannot be arbitrarily set. The length of the baseline stabilization time interval should be based on the premise that the resistance of the gas detection array can reach a stable state. Simultaneously, the gas test flow rate setting must balance the observability of the resistance change curve and the overall efficiency of the test. If the flow rate is set too fast, it will be difficult to monitor the resistance change curve; if the flow rate is set too slow, the overall exhalation test will take too long.

[0079] In some embodiments, the second change curve of the resistance of the gas detection array in S104 specifically includes:

[0080] The resistance of the gas detection array changes under the action of the first mixed gas; the ratio of background gas and the exhaled breath sample in the first mixed gas decreases over time until it becomes 0.

[0081] Specifically, during the response phase, the background gas path is closed, while the test gas path is open. The test gas is gradually drawn into the gas chamber, while the background gas is gradually expelled. The resistance of the gas detection array interacts with the test gas, altering its electrical characteristics. When only the test gas is being drawn in and expelled at a constant rate in the gas chamber, the resistance stabilizes again. The second curve showing the resistance change of the gas detection array under the influence of the first mixed gas shows that the ratio of background gas to the test exhaled breath sample in the first mixed gas decreases over time until it reaches zero, indicating that the gas chamber is filled with the test gas.

[0082] Similarly, the length of the response test period should be set based on the premise that the resistance of the gas detection array can reach a stable state.

[0083] In some embodiments, the third change curve of the resistance of the gas detection array in S105 specifically includes:

[0084] The resistance of the gas detection array changes under the action of the second mixed gas; the ratio of background gas and the exhaled breath sample in the second mixed gas increases over time until it becomes 1.

[0085] Specifically, during the recovery phase, the background gas path is opened, while the test gas path is closed. The test gas is gradually expelled from the gas chamber, while the background gas is gradually expelled. Under the cleansing effect of the background gas, the surface adsorbed test gas of the gas detection array gradually desorbs, altering its electrical properties. When only background gas is being expelled and expelled at a constant rate in the gas chamber, the resistance stabilizes again. The second curve showing the resistance change of the gas detection array under the action of the second mixed gas shows that the ratio of background gas to the test exhaled breath sample in the second mixed gas increases over time until it reaches 1, indicating that the gas chamber is filled with background gas.

[0086] Similarly, the interval length for the baseline recovery period should be set based on the premise that the resistance of the gas detection array can reach a stable state.

[0087] The technical solutions provided by the present invention will be further illustrated below with several specific examples.

[0088] Example 1:

[0089] The present invention provides a breath test method that offers a non-invasive, large-scale early screening method for potential high-risk groups for lung cancer.

[0090] Using the exhalation detection method provided by this invention, taking the exhalation detection of lung tumor patients as an example, the exhalation of the subjects is collected, tested, and analyzed, including the following steps:

[0091] Step a, Breath Collection and Preparation Stage: Use a gas sampling bag to collect breath samples from lung cancer patients (benign and malignant tumors) and healthy controls. Connect the sampled gas bag to the system's gas inlet, using indoor air as the background gas.

[0092] Step b, Test parameter settings: Connect to the system's WiFi in the host computer, set the gas test flow rate to 100 sccm (mL / min), and the test time (baseline, response, and recovery, 2 min each). The gas flow rate remains constant throughout the test.

[0093] Step c, baseline stage: The three-way solenoid valve is closed, the gas path of the gas to be measured is closed, the gas path of the background gas inlet is unobstructed, the background gas is drawn by the micro vacuum pump and passes through the drying module, the gas mass flow meter and the gas chamber in sequence before being discharged, and the baseline resistance of the gas detection array gradually reaches a stable state under the action of background air.

[0094] Step d, Response Phase: After 2 minutes, the three-way solenoid valve switches to the open state under the control of the host computer. The background gas path is closed and the gas path to be tested is opened. The exhaled sample to be tested is drawn by the micro vacuum pump and passes through the drying module and the gas mass flow meter in sequence before entering the gas chamber. After the gas detection array comes into contact with the gas to be tested, it interacts with the gas and its electrical characteristics change, thus entering the response phase.

[0095] Step e, Recovery Phase: After 2 minutes, the three-way solenoid valve switches to the closed state under the control of the host computer. The gas path to be tested is closed, and the background gas path is opened. Under the background gas purging, the gas molecules to be tested adsorbed on the surface of the gas detection array are desorbed, and the resistance of the gas detection array returns to the baseline state. The test automatically stops after 2 minutes, completing one test. Replace the exhaled breath sample for the next test.

[0096] Step f, Data Processing Stage: The resistance changes of the gas detection array in the baseline, response, and recovery stages are used as the output data of a test. The Fisher linear discriminant method is used to process the data and classify the exhalations of the two groups of people. Figure 2 The box plot of discrimination scores for lung cancer patients and healthy control groups provided in this embodiment of the invention shows that the median discrimination scores (black line in the box plot) of healthy people and lung cancer patients are completely separated, and their quartile boundaries do not overlap, indicating that healthy people and lung cancer patients can be basically distinguished.

[0097] In summary, the breath detection method provided by this invention can non-invasively, quickly and effectively distinguish between lung cancer patients and healthy individuals, and is expected to serve as an auxiliary method for clinically identifying patients with lung cancer at different stages.

[0098] Example 2:

[0099] Chronic kidney disease (CKD) has become a major chronic disease that seriously threatens human life and health due to its high incidence and high complication rate. The main clinical manifestation is abnormal glomerular filtration rate (GFR). If not detected in time, it may progress to stage 5, i.e., uremia. Clinically, serum creatinine levels are usually used to indirectly express glomerular filtration rate for diagnosis, but this usually requires time-consuming and invasive testing, which is not conducive to early screening and early warning of chronic kidney disease. Furthermore, there is no gold standard for clinically assessing the degree of health recovery in uremia patients after kidney transplantation. The breath test method provided by this invention offers a non-invasive, real-time monitoring method for the health recovery of uremia patients after kidney transplantation.

[0100] Using the breath detection method provided by this invention, taking the breath detection of uremia patients as an example, the breath of the subjects is collected, tested, and analyzed, including the following steps:

[0101] Step a, Breath Collection and Preparation Stage: Use a gas sampling bag to collect breath samples from uremia patients before, 7 days after, and 14 days after kidney transplantation. Connect the sampled gas bag to the system's gas inlet, using indoor air as the background gas.

[0102] Step b, Test parameter settings: Connect to the system's WiFi in the host computer, set the gas test flow rate to 100 sccm (mL / min), and the test time (baseline, response, and recovery, 2 min each). The gas flow rate remains constant throughout the test.

[0103] Step c, baseline stage: The three-way solenoid valve is closed, the gas path of the gas to be measured is closed, the gas path of the background gas inlet is unobstructed, the background gas is drawn by the micro vacuum pump and passes through the drying module, the gas mass flow meter and the gas chamber in sequence before being discharged, and the baseline resistance of the gas detection array gradually reaches a stable state under the action of background air.

[0104] Step d, Response Phase: After 2 minutes, the three-way solenoid valve switches to the open state under the control of the host computer. The background gas path is closed and the gas path to be tested is opened. The exhaled sample to be tested is drawn by the micro vacuum pump and passes through the drying module and the gas mass flow meter in sequence before entering the gas chamber. After the gas detection array comes into contact with the gas to be tested, it interacts with the gas and its electrical characteristics change, thus entering the response phase.

[0105] Step e, Recovery Phase: After 2 minutes, the three-way solenoid valve switches to the closed state under the control of the host computer. The gas path to be tested is closed, and the background gas path is opened. Under the background gas purging, the gas molecules to be tested adsorbed on the surface of the gas detection array are desorbed, and the resistance of the gas detection array returns to the baseline state. The test automatically stops after 2 minutes, completing one test. Replace the exhaled breath sample for the next test.

[0106] Step f, Data Processing Stage: The resistance changes of the gas detection array in the baseline, response, and recovery stages are used as the output data of a single test. The data are processed using the canonical discrimination method to classify the exhaled breath.

[0107] Tables 1 and 2 are summaries of canonical discriminant functions obtained using Fisher discriminant analysis and their corresponding Wilks' Lambda tables, provided in embodiments of the present invention.

[0108] Table 1

[0109] function Eigenvalues Percentage of variance Cumulative percentage Canonical correlation 1 2.852 66.2 66.2 0.860 2 27.6 27.6 93.7 0.737 3 0.270 6.3 100.0 0.461

[0110] Table 2

[0111]

[0112] Fisher discriminant analysis yielded the canonical discriminant function. The output of the canonical discriminant function reflects the eigenvalues, percentage of variance, cumulative percentage, and canonical correlation. Discriminant function 3 had a variance percentage of only 6.3%, while discriminant functions 1 and 2 explained most of the variance. The Wickel Lambda table compared the significance of different discriminant functions; a significance level less than 0.05 indicates that the function's judgment is meaningful. Combining Tables 1 and 2, the centroid plots of the canonical discriminant function groups were finally obtained. Analysis showed that the centroids of the groups were completely separated before surgery, 7 days post-surgery, and 14 days post-surgery, indicating that uremia patients could be basically distinguished before and 7 days post-surgery from those 14 days post-surgery.

[0113] In summary, the breath test method provided by this invention can non-invasively, rapidly and effectively assess the degree of health recovery of uremia patients after kidney transplantation, and is expected to serve as an auxiliary method for monitoring the degree of health recovery of uremia patients in clinical practice.

[0114] Figure 3 This is one of the structural schematic diagrams of the breath detection device provided in the embodiments of the present invention, such as... Figure 3 As shown, the device includes:

[0115] (1) As an air inlet, it is used for the intake of the exhaled breath sample to be tested and the background air; (2) It is a three-way solenoid valve, which is controlled by the host computer and automatically switches the air inlet during the test; (3) It is a power module; (4) It is a high-precision gas mass flow meter, which is used to control the gas test flow rate during the test and reduce system error; (5) and (6) It is a test chamber, which is equipped with an eight-channel non-redundant sensor; (7) It is an air pump; (8) It is a control circuit module, which is used to connect to an external PC to realize automatic control of the entire test process; (9) It is a flow meter transmission and control module, which is used to set the flow meter parameters; (10) It is a PC terminal, which is used to receive the test data of the test chamber in real time and perform test visualization processing.

[0116] Optionally, the breath test device is an offline portable breath test device, which is more suitable for primary healthcare institutions and individual users.

[0117] Figure 4 This is a second schematic diagram of the structure of the breath detection device provided in the embodiment of the present invention, as shown below. Figure 4 As shown, the device includes at least:

[0118] The parameter setting unit 401 is used to set the gas test flow rate and test time period of the gas mass flow meter. The test time period includes a baseline stabilization time period, a response test time period, and a baseline recovery time period.

[0119] The sampling unit 402 is used to extract background gas and pre-collected breath samples to be tested by a micro vacuum pump. After drying and flow rate control by the gas mass flow meter, the samples are respectively input to the background gas inlet and the test gas inlet.

[0120] The baseline detection unit 403 is used to set the three-way solenoid valve to be closed, the gas path of the gas to be tested to be closed, and the background gas path to be opened during the baseline stabilization period, and to detect the first change curve of the resistance of the gas detection array.

[0121] The response detection unit 404 is used to switch the three-way solenoid valve to the open state, open the gas path of the gas to be tested, close the background gas path, and detect the second change curve of the resistance of the gas detection array during the response test time period.

[0122] The recovery detection unit 405 is used to switch the three-way solenoid valve to the closed state during the recovery baseline time period, close the gas path of the gas to be tested, open the background gas path, and detect the third change curve of the resistance of the gas detection array.

[0123] Data processing unit 406 is used to determine the exhalation curve of the exhalation sample to be tested based on the first change curve, the second change curve and the third change curve;

[0124] The data analysis unit 407 is used to determine the health status of individuals corresponding to different test breath samples based on the exhalation curves of different test breath samples.

[0125] In some embodiments, the data analysis unit 407 includes:

[0126] The discriminant analysis module is used to perform discriminant analysis on the exhalation curves of different test exhalation samples using the Fisher linear discriminant function to obtain classification results;

[0127] The determination module is used to determine the health status of the individual corresponding to the breath sample to be tested based on the classification results.

[0128] In some embodiments, when the different breath samples to be tested are breath samples from different individuals within the same time period, the classification result is used to distinguish the health status of the different individuals; when the breath samples to be tested are breath samples from the same individual within different time periods, the classification result is used to characterize the changes in the health status of the same individual within different time periods.

[0129] In some embodiments, the gas test flow rate and test time period of the gas mass flow meter, as well as the state switching of the three-way solenoid valve, are controlled by a host computer.

[0130] In some embodiments, the baseline detection unit 403 includes:

[0131] The first detection module is used to detect the first change curve of the resistance of the gas detection array under the action of the background gas.

[0132] In some embodiments, the response detection unit 404 includes:

[0133] The second detection module is used to detect the second change curve of the resistance of the gas detection array under the action of the first mixed gas; the ratio of the background gas and the exhaled sample to be tested in the first mixed gas decreases over time until it becomes 0.

[0134] In some embodiments, the recovery detection unit 405 includes:

[0135] The third detection module is used to detect the third change curve of the resistance of the gas detection array under the action of the second mixed gas; the ratio of the background gas and the exhaled sample to be tested in the second mixed gas increases with time until it becomes 1.

[0136] It is understood that the detailed functional implementation of each of the above units / modules can be found in the description in the aforementioned method embodiments, and will not be repeated here.

[0137] It should be understood that the above-described device is used to execute the methods in the above embodiments. The implementation principle and technical effect of the corresponding program modules in the device are similar to those described in the above methods. The working process of the device can be referred to the corresponding process in the above methods, and will not be repeated here.

[0138] Based on the methods described in the above embodiments, this invention provides an electronic device. The device may include at least one memory for storing a program and at least one processor for executing the program stored in the memory. When the program stored in the memory is executed, the processor performs the methods described in the above embodiments.

[0139] Figure 5 This is a schematic diagram of the structure of the electronic device provided in the embodiment of the present invention, such as... Figure 5 As shown, the electronic device may include a processor 501, a communications interface 520, a memory 503, and a communication bus 504. The processor 501, communications interface 502, and memory 503 communicate with each other via the communication bus 504. The processor 501 can call software instructions stored in the memory 503 to execute the methods described in the above embodiments.

[0140] Based on the methods in the above embodiments, this embodiment of the invention provides a computer-readable storage medium storing a computer program that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0141] Based on the methods in the above embodiments, this embodiment of the invention provides a computer program product that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0142] It is understood that the processor in the embodiments of the present invention can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor can be a microprocessor or any conventional processor.

[0143] The method steps in these embodiments of the invention can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can reside in an ASIC.

[0144] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0145] It is understood that the various numerical designations used in the embodiments of the present invention are merely for the convenience of description and are not intended to limit the scope of the embodiments of the present invention.

[0146] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A breath detection method, characterized by, include: Set the gas test flow rate and test time period for the gas mass flow meter, wherein the test time period includes the baseline stabilization time period, the response test time period, and the baseline recovery time period; Background gas and pre-collected breath samples are extracted using a miniature vacuum pump, dried, and then fed into the background gas inlet and the test gas inlet respectively after the flow rate is controlled by the gas mass flow meter. During the baseline stabilization period, the three-way solenoid valve is set to be closed, the gas path of the gas to be tested is closed, the background gas path is opened, and the first change curve of the resistance of the gas detection array is detected. During the response test period, the three-way solenoid valve is switched to the open state, the gas path to be tested is opened, the background gas path is closed, and the second change curve of the resistance of the gas detection array is detected. During the baseline recovery period, the three-way solenoid valve is switched to the closed state, the gas path to be tested is closed, the background gas path is opened, and the third change curve of the resistance of the gas detection array is detected. Based on the first change curve, the second change curve, and the third change curve, the exhalation curve of the exhalation sample to be tested is determined; Based on the exhalation curves of different test exhalation samples, the health status of individuals corresponding to different test exhalation samples is determined.

2. The breath test method of claim 1, wherein, The method of determining the health status of individuals corresponding to different breath samples based on their exhalation curves includes: The expiratory curves of different test expiratory samples were analyzed using the Fisher linear discriminant function to obtain classification results; Based on the classification results, the health status of the individual corresponding to the breath sample to be tested is determined.

3. The exhalation detection method according to claim 2, characterized in that, When the different breath samples to be tested are breath samples from different individuals within the same time period, the classification result is used to distinguish the health status of the different individuals; when the breath samples to be tested are breath samples from the same individual within different time periods, the classification result is used to characterize the changes in the health status of the same individual within different time periods.

4. The exhalation detection method according to claim 1, characterized in that, The gas test flow rate and test time period of the gas mass flow meter, as well as the state switching of the three-way solenoid valve, are controlled by the host computer.

5. The exhalation detection method according to claim 1, characterized in that, The first change curve of the resistance of the gas detection array includes: The resistance of the gas detection array is measured using the first change curve under the influence of the background gas.

6. The exhalation detection method according to claim 5, characterized in that, The second resistance variation curve of the gas detection array includes: The resistance of the gas detection array is measured using the second change curve under the action of the first mixed gas; the ratio of the background gas and the exhaled breath sample to be tested in the first mixed gas decreases over time until it becomes 0.

7. The exhalation detection method according to claim 6, characterized in that, The third curve showing the change in resistance of the gas detection array includes: The resistance of the gas detection array is measured under the action of the second mixed gas, and the third change curve is obtained. The ratio of the background gas and the exhaled breath sample to be tested in the second mixed gas increases over time until it becomes 1.

8. A breath detection device, characterized in that, include: The parameter setting unit is used to set the gas test flow rate and test time period of the gas mass flow meter. The test time period includes the baseline stabilization time period, the response test time period, and the baseline recovery time period. The sampling unit is used to extract background gas and pre-collected breath samples to be tested using a micro vacuum pump. After drying and flow rate control by the gas mass flow meter, the samples are respectively input into the background gas inlet and the test gas inlet. The baseline detection unit is used to set the three-way solenoid valve to be closed, the gas path of the gas to be tested to be closed, and the background gas path to be open during the baseline stabilization period, and to detect the first change curve of the resistance of the gas detection array. The response detection unit is used to switch the three-way solenoid valve to the open state, open the gas path of the gas to be tested, close the background gas path, and detect the second change curve of the resistance of the gas detection array during the response test period. The recovery detection unit is used to switch the three-way solenoid valve to the closed state during the recovery baseline time period, close the gas path of the gas to be tested, open the background gas path, and detect the third change curve of the resistance of the gas detection array. A data processing unit is used to determine the exhalation curve of the breath sample to be tested based on the first change curve, the second change curve, and the third change curve. The data analysis unit is used to determine the health status of individuals corresponding to different breath samples based on their exhalation curves.

9. An electronic device, characterized in that, include: At least one memory for storing programs; At least one processor is configured to execute a program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to perform the method as described in any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is run on the processor, it causes the processor to perform the method as described in any one of claims 1-7.

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