A method for detecting exhaled breath components and a warning device

Abstract

The application discloses a breath component detection method and early warning device, and belongs to the technical field of biology and new medicine. The time of breath flowing through a gas sensor is prolonged to more than 30 seconds through a time-delay constant-current module, the success rate of detection is improved, the airflow through the sensor is not affected by the blowing strength and speed of the person being measured, the accuracy of gas concentration detection is improved, the dryer removes water vapor to avoid the influence of the humidity of the breath on the sensor, the single-chip microcomputer performs correction operation on the collected temperature and pressure data, the influence of temperature and pressure on the sensor is excluded, the individual factors such as the age, constitution and disease state of the person being measured are eliminated to the greatest extent, and the problem that the breath component detection cannot be standardized is solved. The detected component gas is determined as a reference, an early warning index is obtained through exponential weighting operation, obvious early warning prompts are given while data is displayed, the breath detection result has more reference value, and the technology has a real clinical application prospect.

Description

Technical Field

[0001] This invention belongs to the field of biotechnology and new medicine, specifically relating to a method for detecting exhaled breath components and an early warning device. Background Technology

[0002] Exhaled breath composition analysis, as a non-invasive, rapid, and sensitive detection method, shows great promise in assisting the diagnosis of acute and chronic lung diseases. Currently, there is no exhaled breath composition analysis device that has reached a clinical application level. The difficulties lie in the following aspects: First, the MEMS sensors used to detect gas concentration are highly sensitive to parameters such as gas flow rate, temperature, humidity, and pressure, while these parameters in human exhaled breath are affected by individual factors such as age, physical condition, and disease status, making accurate detection difficult. Second, current sensors require a response time of more than 30 seconds, and most subjects cannot complete such a long continuous exhalation, leading to detection failure or inaccurate results. Third, there is a lack of corresponding data processing and comparison methods, making it difficult to provide valuable references or suggestions even if exhaled breath components are accurately detected. Therefore, developing an auxiliary device that can stably collect, accurately detect, scientifically process, and effectively provide suggestions for human exhaled breath is of great significance for advancing the application of exhaled breath composition analysis.

[0003] Chinese patent CN110146651A discloses an exhaled breath detection system based on a gas sensor, comprising two main parts: a gas detection module and a data processing module. The gas acquisition structure incorporates a heating layer and an insulation layer to ensure the temperature of the detected gas is around 40°C, eliminating the impact of temperature differences on sensor accuracy. The sensor unit includes a MEMS ammonia sensor and a MEMS gas sensor, separately located on either side of a dehumidifying membrane to eliminate the influence of humidity and ensure the sensitivity and accuracy of sensor detection. While this disclosed technology partially eliminates the influence of individual factors on the detection results, it does not consider the impact of exhalation pressure on sensor accuracy or the response time of the MEMS sensor, thus making it difficult to apply in practice.

[0004] Chinese patent CN109770905A discloses an offline exhaled nitric oxide (FENO) detection device, including a gas storage bag for storing FENO, an exhaust assembly for delivering FENO, and a FENO generator. The patent focuses on the raw materials and processing technology of the gas storage bag. In use, an asthma patient blows air into the gas storage bag, then connects the bag to the exhaust assembly. A pump then delivers gas to the FENO generator to detect the FENO concentration. This disclosed technology delivers exhaled air from the gas storage bag to the detection component via a pump. If implemented correctly, a stable pressure airflow can be obtained, and the contact time between the airflow and the sensor can exceed the sensor's response time. However, this disclosed technology does not consider the influence of temperature and humidity on detection accuracy. Furthermore, it is well known that exhaled nitric oxide decomposes extremely rapidly; this discontinuous method of first blowing air into the gas storage bag and then connecting it for detection cannot obtain accurate results.

[0005] Chinese patent CN111374668A discloses a home-use exhaled breath detector capable of measuring exhaled nitric oxide and lung function data, displaying them locally on the device and / or via a mobile app for patient viewing. This disclosed technology incorporates an exhaled breath pressure sensor, but this is only used to obtain lung function parameters and lacks pressure compensation adjustment for nitric oxide sensor data. Therefore, the obtained test results are inevitably affected by exhaled breath pressure. While this disclosed technology considers the impact of humidity on sensor accuracy by introducing a "humidity balancer," it does not explain how this device achieves "balance" in the humidity of the exhaled breath reaching the sensor. Furthermore, this disclosed technology does not address the issue of "data processing and comparative analysis." Since exhaled nitric oxide concentration does not have a normal range, even if it is accurately detected, it is impossible to determine whether it is high or low, thus lacking clinical application value.

[0006] In summary, the shortcomings of existing exhaled air detection technologies are: they cannot completely eliminate the influence of individual factors such as the airflow rate, temperature, humidity, and pressure of human exhaled air on the test results; they cannot ensure that all patients' exhalation time exceeds the corresponding time of the sensor; and they cannot provide results or suggestions that are of reference value. Summary of the Invention

[0007] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method and early warning device for detecting exhaled gas components, so as to solve the problems in the prior art that cannot completely eliminate the influence of individual factors such as human exhaled airflow rate, temperature, humidity, and pressure on the detection results, cannot ensure that all patients' exhalation time exceeds the corresponding time of the sensor, and cannot provide results judgment or prompts with reference value.

[0008] To achieve the above objectives, the present invention employs the following technical solution:

[0009] This invention discloses an exhaled breath composition detection and early warning device, comprising: a mouth and nose mask, a dryer, a filter, a time-delay constant current module, a detection air tube, a temperature sensor, a pressure sensor, a gas sensor assembly, a microcontroller, a display screen, and ten-level warning lights;

[0010] The mouth and nose mask, dryer, and filter are connected in sequence. The outlet of the filter is connected to the time-delay constant current module. The time-delay constant current module is connected to the gas sensor assembly through the detection air tube. The gas sensor assembly is connected to the microcontroller. The microcontroller is connected to the display screen and the ten-level warning light. Temperature sensors and pressure sensors are installed on the detection air tube, and both temperature sensors and pressure sensors are connected to the microcontroller.

[0011] The microcontroller is used to obtain a warning index through exponential weighting calculation based on the data transmitted by the temperature sensor, pressure sensor and gas sensor components, and then transmits the index to the display screen and the ten-level warning light.

[0012] Preferably, the time-delay constant current module includes: an air inlet pipe, an air injection port, a blowing piston, an air injection nozzle, an air injection piston, a buffer tank, a buffer piston, an exhaust pipe, and an exhaust piston; the air inlet pipe is connected to a filter, and an air injection port is provided on the air inlet pipe; the air inlet pipe is connected to one end of the buffer tank through the air injection nozzle at the air injection port, and the other end of the buffer tank is connected to a detection air pipe through the exhaust pipe; a blowing piston is provided inside the air inlet pipe, an air injection piston is provided at the air injection nozzle, a buffer piston is provided in the buffer tank, and an exhaust piston is provided inside the exhaust pipe.

[0013] Preferably, the gas sensor assembly includes: an infrared oxygen sensor, an infrared carbon dioxide sensor, an electrochemical carbon monoxide sensor, an electrochemical nitric oxide sensor, a gas chamber cap, and a connecting pipe; the sensor heads of the infrared oxygen sensor, the infrared carbon dioxide sensor, the electrochemical carbon monoxide sensor, and the electrochemical nitric oxide sensor are all covered with gas chamber caps, and the plurality of gas chamber caps are connected by a connecting pipe, with one end of the connecting pipe connected to the detection gas pipe and the other end being the exhaust end.

[0014] This invention also discloses a method for detecting exhaled breath components, comprising:

[0015] Acquire gas concentration parameters and convert them into digital gas concentration signals; collect digital gas temperature signals and digital pressure signals.

[0016] Temperature and pressure corrections are applied to the digital gas concentration signal.

[0017] Display the corrected gas standard concentration data;

[0018] The early warning index is obtained by performing an index-weighted calculation on the gas standard concentration data.

[0019] The warning index will be displayed and a warning will be issued.

[0020] Preferably, the gas includes oxygen, carbon dioxide, carbon monoxide, and nitric oxide, and their concentration parameters are obtained by infrared oxygen sensor, infrared carbon dioxide sensor, electrochemical carbon monoxide sensor, and electrochemical nitric oxide sensor, respectively; the gas temperature digital signal is collected by temperature sensor, and the gas pressure digital signal is collected by pressure sensor.

[0021] Preferably, a microcontroller is used to acquire the gas concentration parameters and convert them into a digital gas concentration signal, and the gas concentration digital signal is then corrected for temperature and pressure by combining the gas temperature digital signal and the pressure digital signal.

[0022] Preferably, the microcontroller's temperature correction function for oxygen and carbon dioxide is:

[0023] Ch=C1-0.334·(T1-T s )

[0024] Where Ch is the temperature-corrected percentage value of the gas concentration, C1 is the percentage value of the gas concentration after analog-to-digital conversion to the output of the infrared oxygen sensor or infrared carbon dioxide sensor and subsequent digital-to-analog conversion, T1 is the temperature value in degrees Celsius output by the temperature sensor, and T... s This is the calibration temperature in degrees Celsius.

[0025] Preferably, the microcontroller's temperature correction functions for carbon monoxide and nitric oxide are:

[0026] Cd = C² - 0.127 * (T₁ - T₂) s )

[0027] Where Cd is the temperature-corrected gas concentration in ppm, C2 is the gas concentration in ppm after analog-to-digital conversion to the output of the electrochemical carbon monoxide sensor or electrochemical nitric oxide sensor and subsequent digital-to-analog conversion, T1 is the temperature sensor output in degrees Celsius, and T... s This is the calibration temperature in degrees Celsius.

[0028] Preferably, the microcontroller pressure correction calculation method is as follows:

[0029] C = Ch·(1-0.131·P)

[0030] C = Cd·(1-0.131·P)

[0031] Wherein, C is the concentration value of the four gases after pressure correction; Ch is the concentration value of oxygen and carbon dioxide after temperature correction; Cd is the concentration value of carbon monoxide and nitrogen monoxide after temperature correction; and P is the pressure value of kilopascals output by the pressure sensor (33).

[0032] Preferably, a microcontroller is used to perform an exponential weighting calculation on the gas standard concentration data to obtain the warning index. The warning index calculation function of the microcontroller is as follows:

[0033] WI = 6·C O2 -5·C Co2 +0.2·C CO +0.2·C NO -0.66

[0034] Wherein, WI is the early warning index; C O2 This is the pressure-corrected percentage value of oxygen concentration; C CO2 This is the percentage value of carbon dioxide concentration after pressure correction; C CO This represents the pressure-corrected carbon monoxide concentration in ppm; C NO This is the pressure-corrected nitric oxide concentration in ppm.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The exhaled breath composition detection and early warning device disclosed in this invention extends the time for exhaled airflow to pass through the gas sensor to more than 30 seconds through the design of a time-delay constant current module, exceeding the response time of the gas sensor and improving the success rate of exhaled breath composition detection. Furthermore, this design ensures that the airflow passing through the sensor is unaffected by the subject's blowing force and speed, improving the accuracy of gas concentration detection. The device removes moisture through a dryer, avoiding the influence of exhaled breath humidity on the sensor, and uses a microcontroller to correct temperature and pressure data, eliminating the influence of temperature and pressure on the sensor. This minimizes the impact of individual factors such as the subject's age, physical condition, and disease status, solving the problem of the lack of standardization in exhaled breath composition detection.

[0037] The exhaled breath component detection method disclosed in this invention determines the tested gas component as a benchmark and obtains a warning index through index weighting calculation. While displaying the data, it provides clear warning prompts, making the exhaled breath detection results more valuable for reference and enabling exhaled breath component detection technology to achieve real clinical application prospects. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the exhaled breath composition detection and early warning device of the present invention;

[0039] Figure 2 This is a schematic diagram of the delay constant current module structure of the present invention;

[0040] Figure 3 This is a schematic diagram of the air intake of the time-delay constant current module of the present invention;

[0041] Figure 4This is a schematic diagram of the exhaust of the time-delay constant current module of the present invention;

[0042] Figure 5 This is a schematic diagram of the detection and early warning hardware components of the present invention;

[0043] Figure 6 This is a flowchart of the detection and early warning operation of the present invention.

[0044] Wherein: 11-Nose mask; 12-Dryer; 13-Filter; 20-Delay constant flow module; 21-Inlet pipe; 22-Inlet port; 23-Blowing piston; 231-Blowing piston head; 232-Blowing spring; 233-Blowing piston rod; 24-Inlet nozzle; 25-Inleting piston; 251-Inleting piston head; 252-Inleting spring; 253-Inleting piston rod; 26-Buffer piston; 261-Buffer piston head; 262-Buffer spring; 263-Buffer piston rod; 27-Buffer tank; 28-Exhaust pipe; 29-Exhaust piston; 291-Exhaust piston head; 292-Exhaust buffer spring; 293-Exhaust buffer piston rod; 31-Detection gas tube; 32-Temperature sensor; 33-Pressure sensor; 40-Gas sensor assembly; 41-Inlet; 42-Gas chamber cap; 43-Outlet; 44-Infrared oxygen sensor; 45-Infrared carbon dioxide sensor; 46-Electrochemical carbon monoxide sensor; 47-Electrochemical nitric oxide sensor; 48-Exhaust end; 51-Microcontroller; 52-Display screen; 53-Level 10 warning light. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0047] The present invention will now be described in further detail with reference to the accompanying drawings:

[0048] This invention discloses an exhaled breath composition detection and early warning device, comprising: a mouth and nose mask 11, a dryer 12, a filter 13, a time-delay constant current module 20, a detection air tube 31, a temperature sensor 32, a pressure sensor 33, a gas sensor assembly 40, a microcontroller 51, a display screen 52, and a ten-level warning light 53.

[0049] The mouth and nose mask 11, dryer 12, and filter 13 are connected in sequence. The outlet of filter 13 is connected to a time-delay constant current module 20. The time-delay constant current module 20 is connected to a gas sensor assembly 40 through a detection tube 31. The gas sensor assembly 40 is connected to a microcontroller 51. The microcontroller 51 is connected to a display screen 52 and a ten-level warning light 53. A temperature sensor 32 and a pressure sensor 33 are respectively installed on the detection tube 31, and both the temperature sensor 32 and the pressure sensor 33 are connected to the microcontroller 51. The microcontroller 51 is used to obtain a warning index through exponential weighting calculation based on the data transmitted by the temperature sensor 32, the pressure sensor 33, and the gas sensor assembly 40, and transmits it to the display screen 52 and the ten-level warning light 53. The time-delay constant current module 20 includes: an air inlet pipe 21, an air injection port 22, an air blowing piston 23, an air injection nozzle 24, an air injection piston 25, a buffer tank 27, a buffer piston 26, an exhaust pipe 28, and an exhaust piston 29. The air inlet pipe 21 is connected to the filter 13, and an air injection port 22 is provided on the air inlet pipe 21. At the air injection port 22, the air inlet pipe 21 is connected to one end of the buffer tank 27 through the air injection nozzle 24. The other end of the buffer tank 27 is connected to the detection air pipe 31 through the exhaust pipe 28. An air blowing piston 23 is provided inside the air inlet pipe 21, an air injection piston 25 is provided at the air injection nozzle 24, a buffer piston 26 is provided in the buffer tank 27, and an exhaust piston 29 is provided inside the exhaust pipe 28. Through the design of the time-delay constant current module 20, the device extends the time for the exhaled airflow to pass through the gas sensor to more than 30 seconds. This design exceeds the response time of gas sensors, improving the success rate of exhaled breath component detection. Furthermore, the airflow passing through the sensor is unaffected by the subject's blowing force and speed, enhancing the accuracy of gas concentration detection. The gas sensor assembly 40 includes: an infrared oxygen sensor 44, an infrared carbon dioxide sensor 45, an electrochemical carbon monoxide sensor 46, an electrochemical nitric oxide sensor 47, a gas chamber cap 42, and connecting tubing. Each of the infrared oxygen sensor 44, infrared carbon dioxide sensor 45, electrochemical carbon monoxide sensor 46, and electrochemical nitric oxide sensor 47 has a gas chamber cap 42 covering its sensor head. These gas chamber caps 42 are connected by connecting tubing, with one end connected to the detection air tube 31 and the other end serving as the exhaust end 48. The device uses four tested components—oxygen, carbon dioxide, carbon monoxide, and nitric oxide—as benchmarks and obtains a warning index through exponential weighting. While displaying the data, it provides clear indications via a ten-level warning light 53, making the exhaled breath detection results more valuable and enabling exhaled breath component detection technology to achieve genuine clinical application prospects.

[0050] Furthermore, the concentration parameters of oxygen, carbon dioxide, carbon monoxide, and nitric oxide are obtained through infrared oxygen sensor 44, infrared carbon dioxide sensor 45, electrochemical carbon monoxide sensor 46, and electrochemical nitric oxide sensor 47. Digital signals of gas temperature are acquired through temperature sensor 32, and digital signals of gas pressure are acquired through pressure sensor 33. A microcontroller 51 is used to convert the acquired gas concentration parameters into digital signals of gas concentration, and temperature and pressure corrections are performed on the digital signals of gas concentration based on the gas temperature and pressure signals. The function for temperature correction of oxygen and carbon dioxide by the microcontroller 51 is as follows:

[0051] Ch=C1-0.334·(T1-T s )

[0052] Where Ch is the temperature-corrected percentage value of the gas concentration, C1 is the percentage value of the gas concentration after analog-to-digital conversion to the output of infrared oxygen sensor 44 or infrared carbon dioxide sensor 45 and subsequent digital-to-analog conversion, T1 is the temperature value in degrees Celsius output by temperature sensor 32, and T... s This is the calibration temperature in degrees Celsius.

[0053] The functions for temperature correction of carbon monoxide and nitric oxide in a 51 microcontroller are as follows:

[0054] Cd = C² - 0.127 * (T₁ - T₂) s )

[0055] Where Cd is the temperature-corrected gas concentration in ppm, C2 is the gas concentration in ppm after analog-to-digital conversion to the output of electrochemical carbon monoxide sensor 46 or electrochemical nitric oxide sensor 47 and subsequent digital-to-analog conversion, T1 is the temperature in degrees Celsius output by temperature sensor 32, and T... s This is the calibration temperature in degrees Celsius.

[0056] The pressure correction calculation method of the 51 microcontroller is as follows:

[0057] C = Ch·(1-0.131·P)

[0058] C = Cd·(1-0.131·P)

[0059] Where C represents the pressure-corrected concentration values ​​of the four gases; Ch represents the temperature-corrected concentration values ​​of oxygen and carbon dioxide; Cd represents the temperature-corrected concentration values ​​of carbon monoxide and nitric oxide; and P represents the pressure value in kilopascals output by pressure sensor 33.

[0060] The early warning index is obtained by performing an exponential weighting operation on the gas standard concentration data using a single-chip microcomputer (MCU). The early warning index calculation function of the MCU is as follows:

[0061] WI = 6·C O2-5·C Co2 +0.2·C CO +0.2·C NO -0.66

[0062] Wherein, WI is the early warning index; C O2 This is the pressure-corrected percentage value of oxygen concentration; C CO2 This is the percentage value of carbon dioxide concentration after pressure correction; C CO This represents the pressure-corrected carbon monoxide concentration in ppm; C NO This is the pressure-corrected nitric oxide concentration in ppm.

[0063] This invention also discloses a method for detecting exhaled breath components, comprising:

[0064] The gas concentration parameters are acquired and converted into digital signals, and digital signals of gas temperature and pressure are collected. The gases include oxygen, carbon dioxide, carbon monoxide, and nitric oxide, and their concentration parameters are acquired by infrared oxygen sensor 44, infrared carbon dioxide sensor 45, electrochemical carbon monoxide sensor 46, and electrochemical nitric oxide sensor 47, respectively. Digital signals of gas temperature are collected by temperature sensor 32, and digital signals of gas pressure are collected by pressure sensor 33.

[0065] Temperature and pressure corrections are performed on the digital gas concentration signal; a microcontroller (51) is used to acquire the gas concentration parameters and convert them into a digital gas concentration signal, and then combined with the digital gas temperature and pressure signals to perform temperature and pressure corrections on the digital gas concentration signal. The temperature correction function of the microcontroller (51) for oxygen and carbon dioxide is as follows:

[0066] Ch=C1-0.334·(T1-T s )

[0067] Where Ch is the temperature-corrected percentage value of the gas concentration, C1 is the percentage value of the gas concentration after analog-to-digital conversion to the output of the infrared oxygen sensor (44) or infrared carbon dioxide sensor (45) and digital-to-analog conversion, T1 is the temperature value in degrees Celsius output by the temperature sensor (32), and T s This is the calibration temperature in degrees Celsius.

[0068] The temperature correction functions for carbon monoxide and nitric oxide in the microcontroller (51) are as follows:

[0069] Cd = C² - 0.127 * (T₁ - T₂) s )

[0070] Where Cd is the temperature-corrected gas concentration in ppm, C2 is the gas concentration in ppm after analog-to-digital conversion to the output of the electrochemical carbon monoxide sensor (46) or electrochemical nitric oxide sensor (47) and digital-to-analog conversion, T1 is the temperature in degrees Celsius output by the temperature sensor (32), and T s This is the calibration temperature in degrees Celsius.

[0071] The pressure correction calculation method of the microcontroller (51) is as follows:

[0072] C = Ch·(1-0.131·P)

[0073] C = Cd·(1-0.131·P)

[0074] Wherein, C is the concentration value of the four gases after pressure correction; Ch is the concentration value of oxygen and carbon dioxide after temperature correction; Cd is the concentration value of carbon monoxide and nitric oxide after temperature correction; P is the pressure value of kilopascal output by pressure sensor (33).

[0075] Display the corrected gas standard concentration data;

[0076] The gas standard concentration data are subjected to exponential weighting to obtain the warning index; the four gas standard concentration data after correction by the microcontroller 51 are output to the display 52 interface.

[0077] The early warning index is obtained by performing an exponential weighting operation on the gas standard concentration data using a single-chip microcomputer (MCU). The early warning index calculation function of the MCU is as follows:

[0078]

[0079] Among them, WI is the early warning index; This is the pressure-corrected percentage value of oxygen concentration. This is the percentage value of carbon dioxide concentration after pressure correction; C CO This represents the pressure-corrected carbon monoxide concentration in ppm; C NO This is the pressure-corrected nitric oxide concentration in ppm.

[0080] The warning index is output and displayed, and a warning is issued; the four gas concentration data are processed by the single-chip microcomputer 51 to obtain the warning index, which is output to the display interface 52 and drives the ten-level warning light 53 to indicate the warning level.

[0081] Figure 1As shown, the exhaled breath composition detection and early warning device of this patent includes a nasal mask 11, a dryer 12, a filter 13, a time-delay constant flow module 20, a detection air tube 31, a temperature sensor 32, a pressure sensor 33, a gas sensor assembly 40, a microcontroller 51, a display screen 52, and a ten-level warning light 53. The nasal mask 11, dryer 12, filter 13, time-delay constant flow module 20, detection air tube 31, and gas sensor assembly 40 are sequentially connected. The temperature sensor 32, pressure sensor 33, and gas sensor assembly 40 are connected to the microcontroller 51 via signal lines, and the output signal is connected to the display screen 52 and the ten-level warning light 53 via lines.

[0082] Figure 2 As shown, the time-delay constant flow module 20 consists of an air inlet pipe 21, an air blowing piston 23, an air injection port 22, an air injection nozzle 24, an air injection piston 25, a buffer tank 27, a buffer piston 26, an exhaust pipe 28, and an exhaust piston 29. Each piston consists of a piston head, a piston rod, and a spring. The pressure change before and after blowing air drives the coordinated movement of the piston, so that the subject's exhaled air flows unidirectionally, slowly, and stably through the detection air pipe 31.

[0083] Figure 3 As shown, when the subject blows air, the air inlet pipe 21 is under positive pressure, which pushes the air injection piston 25 downward through the air injection port 22. The exhaled air enters the buffer tank 27 through the gap between the air injection nozzle 24 and the air injection piston head 251, pushing the buffer piston 26 downward and compressing the buffer spring 262 to obtain elastic potential energy. At the same time, the blowing pressure pushes the blowing piston 23 to move to the right, and the blowing piston rod 233 is inserted into the exhaust pipe 28, blocking the exhaust piston 29 from moving upward. The exhaust piston head 291 seals the detection air pipe 31.

[0084] Figure 4 As shown, when the subject finishes blowing, the inflation spring 252 returns to its original length, and the inflation piston head 251 blocks the inflation nozzle 24 upward, preventing the positive pressure gas in the buffer tank 27 from flowing out in the reverse direction; at the same time, the blowing spring 232 also returns to its original length, the blowing piston rod 233 moves to the left, releasing the limit of the exhaust piston 29, and the positive pressure in the buffer tank 27 pushes the exhaust piston head 291 upward, connecting the detection air tube 31; as the buffer spring 262 releases its elastic potential energy, it slowly pushes the exhaled air into the detection air tube 31.

[0085] Figure 5As shown, the gas sensor assembly 40 consists of four gas sensors, a gas chamber cap covering its sensing head, and connecting pipes. Exhaled air, slowly pushed in by the delayed constant current module 20, flows through the temperature sensor 32 and pressure sensor 33 on the detection air tube 31, is blown onto the surface of the sensing head from the air inlet 41 of the infrared oxygen sensor 44's gas chamber cap 42, and then exits from the air outlet 43. It then flows sequentially through the infrared carbon dioxide sensor 45, the electrochemical carbon monoxide sensor 46, and the electrochemical nitrogen monoxide sensor 47, finally exiting from the exhaust end 48. The signal output terminals of the temperature sensor 32, pressure sensor 33, and the four gas sensors are connected to the microcontroller 51 via wiring. After a detection and warning calculation process, the calculation result is transmitted from the output terminal of the microcontroller 51 to the display 52 and the ten-level warning light 53 via cable.

[0086] Figure 6 As shown, the exhaled air detection and early warning calculation process is as follows: 1) The analog signals output by the four gas sensors (oxygen, carbon dioxide, carbon monoxide, and nitric oxide) are converted into digital signals of gas concentration by the microcontroller 51; 2) The microcontroller 51 combines the collected digital signals of gas path temperature and pressure to perform temperature and pressure correction calculations on the four gas concentrations; 3) The corrected standard concentration data of the four gases are output to the display 52 interface; 4) The four gas concentration data are subjected to exponential weighting calculation by the microcontroller 51 to obtain the early warning index, which is output to the display 52 interface and drives the ten-level early warning light 53 to indicate the early warning level.

[0087] The temperature correction calculation method of the 51 microcontroller is as follows:

[0088] The temperature correction functions for oxygen and carbon dioxide are:

[0089] Ch=C1-0.334·(T1-T s )

[0090] Where Ch is the temperature-corrected percentage value of the gas concentration, C1 is the percentage value of the gas concentration after analog-to-digital conversion to the output of infrared oxygen sensor 44 or infrared carbon dioxide sensor 45 and subsequent digital-to-analog conversion, T1 is the temperature value in degrees Celsius output by temperature sensor 32, and T s The calibration temperature is in degrees Celsius (Ts = 28°C in this invention);

[0091] The temperature correction functions for carbon monoxide and nitric oxide are:

[0092] Cd = C² - 0.127 * (T₁ - T₂) s )

[0093] Where Cd is the temperature-corrected gas concentration in ppm, C2 is the gas concentration in ppm after analog-to-digital conversion to the output of electrochemical carbon monoxide sensor 46 or electrochemical nitric oxide sensor 47 and subsequent digital-to-analog conversion, T1 is the temperature in degrees Celsius output by temperature sensor 32, and T... s The calibration temperature is in degrees Celsius (Ts = 28°C in this invention).

[0094] The pressure correction calculation method of the 51 microcontroller is as follows:

[0095] C = Ch·(1-0.131·P) or C = Cd·(1-0.131·P)

[0096] Wherein, C is the concentration value of the four gases after pressure correction; Ch is the concentration value of oxygen and carbon dioxide after temperature correction; Ch is the concentration value of carbon monoxide and nitric oxide after temperature correction; and P is the pressure value in kilopascals output by the pressure sensor (33).

[0097] The weighted calculation method for the 51 microcontroller early warning index is as follows:

[0098] The function for calculating the early warning index is:

[0099]

[0100] Among them, WI is the early warning index; This is the pressure-corrected percentage value of oxygen concentration. This is the percentage value of carbon dioxide concentration after pressure correction; C CO This represents the pressure-corrected carbon monoxide concentration in ppm; C NO This is the pressure-corrected nitric oxide concentration in ppm. The WI calculated by the microcontroller 51 according to the above function is always between 0 and 1, representing the level of alertness of the subject's exhaled breath, where 0 indicates no correlation and 1 indicates complete correlation.

[0101] The level 10 warning light 53 consists of ten rectangular LED beads arranged vertically. The microcontroller 51 divides the weighted average WI into several levels, each with a value of 0.1, and outputs the result as an electrical signal through a cable. The signal is then used to drive the N LED beads from bottom to top according to the rounding principle. For example, if the calculated WI is 0.54, it is divided into 5.4 levels, ultimately driving the five LED beads from bottom to top to light up.

[0102] The implementation method of the exhaled breath composition detection and early warning device of the present invention is as follows:

[0103] Before use, turn on the power supply of the device and check that all components are tightly connected.

[0104] When exhaling, the subject blows into the mouth and nose mask 11. The exhaled air first passes through the dryer 12 to remove moisture, then flows through the filter 13 to remove any bacteria or viruses that may be present, and then is injected into the buffer tank 27.

[0105] When the exhalation ends, the exhaled air in the buffer tank 27 slowly enters the detection air tube 31 under the coordinated action of the components of the time-delay constant flow module 20, and flows through the temperature sensor 32, pressure sensor 33 and gas sensor assembly 40 in sequence. The signals from each sensor are input to the microcontroller 51 through the line. The concentration data of the four gases after temperature and pressure correction calculation, as well as the warning index obtained by weighted calculation, are displayed on the display screen 51 interface. At the same time, the ten-level warning lights 53 are lit according to the warning index value.

[0106] After the test is completed, the tester will make a professional judgment based on the data on the display screen 51 and the prompts of the ten-level warning light 53, combined with the test subject's clinical data.

[0107] [Example]:

[0108] According to the above implementation method, the subject's blowing time is 6 seconds, and the time for the buffer tank 27 to exhaust gas into the detection air tube 31 is 42 seconds, which exceeds the 30-second response time required by the gas sensor.

[0109] The data input from each sensor to the 51 microcontroller are as follows: temperature 30.4 degrees Celsius, pressure 0.35 kPa, oxygen 16.8%, carbon dioxide 4.2%, carbon monoxide 1.48 ppm, and nitric oxide 0.67 ppm.

[0110] The gas concentration data after temperature correction by the 51 microcontroller are: oxygen 16.0%, carbon dioxide 3.4%, carbon monoxide 1.18 ppm, and nitric oxide 0.87 ppm.

[0111] The gas concentration data after pressure correction by the 51 microcontroller are: oxygen 15.3%, carbon dioxide 3.2%, carbon monoxide 1.13 ppm, and nitric oxide 0.85 ppm.

[0112] The warning index after weighted calculation by the 51 microcontroller is 0.494;

[0113] The device screen displayed the following test results: oxygen 15.3%, carbon dioxide 3.2%, carbon monoxide 1.13 ppm, nitrogen monoxide 0.85 ppm, warning index 0.494; level 10 warning light 53 had no LEDs lit.

[0114] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A device for detecting and warning of exhaled breath composition, characterized in that, include: The mask includes a mouth and nose mask (11), a dryer (12), a filter (13), a time-delay constant current module (20), a detection air tube (31), a temperature sensor (32), a pressure sensor (33), a gas sensor assembly (40), a microcontroller (51), a display screen (52), and a level 10 warning light (53). The mouth and nose mask (11), dryer (12) and filter (13) are connected in sequence. The outlet of filter (13) is connected to delay constant current module (20). Delay constant current module (20) is connected to gas sensor assembly (40) through detection air tube (31). Gas sensor assembly (40) is connected to microcontroller (51). Microcontroller (51) is connected to display screen (52) and level 10 warning light (53) respectively. Temperature sensor (32) and pressure sensor (33) are respectively installed on detection air tube (31), and both temperature sensor (32) and pressure sensor (33) are connected to microcontroller (51). The microcontroller (51) is used to obtain the warning index by performing an exponential weighted calculation based on the data transmitted by the temperature sensor (32), pressure sensor (33) and gas sensor assembly (40), and transmit it to the display screen (52) and the ten-level warning light (53). The time-delay constant current module (20) includes: an air inlet pipe (21), an air injection port (22), an air blowing piston (23), an air injection nozzle (24), an air injection piston (25), a buffer tank (27), a buffer piston (26), an exhaust pipe (28), and an exhaust piston (29); the air inlet pipe (21) is connected to a filter (13), and an air injection port (22) is provided on the air inlet pipe (21). The air inlet pipe (21) is connected to one end of the buffer tank (27) through the air injection nozzle (24) at the air injection port (22), and the other end of the buffer tank (27) is connected to the detection air pipe (31) through the exhaust pipe (28); an air blowing piston (23) is provided in the air inlet pipe (21), an air injection piston (25) is provided at the air injection nozzle (24), a buffer piston (26) is provided in the buffer tank (27), and an exhaust piston (29) is provided in the exhaust pipe (28); The blowing piston (23), the injection piston (25), the buffer piston (26), and the exhaust piston (29) are all composed of a piston head, a piston rod, and a spring. The blowing pressure pushes the blowing piston (23) to the right, and the blowing piston rod (233) of the blowing piston (23) is inserted into the exhaust pipe (28), blocking the exhaust piston (29) from moving upward. After the subject finishes blowing, the blowing spring (232) of the blowing piston (23) returns to its original length, the blowing piston rod (233) moves to the left, releasing the limit of the exhaust piston (29), and the positive pressure in the buffer tank (27) pushes the exhaust piston head (291) of the exhaust piston (29) to move upward, connecting the detection air tube (31). The buffer spring (262) of the buffer piston (26) releases elastic potential energy and slowly pushes the exhaled air into the detection air tube (31). The gas sensor assembly (40) includes: an infrared oxygen sensor (44), an infrared carbon dioxide sensor (45), an electrochemical carbon monoxide sensor (46), an electrochemical nitric oxide sensor (47), a gas chamber cap (42), and a connecting pipe; the sensing heads of the infrared oxygen sensor (44), the infrared carbon dioxide sensor (45), the electrochemical carbon monoxide sensor (46), and the electrochemical nitric oxide sensor (47) are all covered with gas chamber caps (42), and several gas chamber caps (42) are connected by a connecting pipe, and one end of the connecting pipe is connected to the detection gas pipe (31), and the other end is the exhaust end (48).

2. A method of detecting a component of exhaled breath, characterized by, The exhaled breath composition detection and early warning device according to claim 1 is implemented, comprising: Acquire gas concentration parameters and convert them into digital gas concentration signals; collect digital gas temperature signals and digital pressure signals. Temperature and pressure corrections are applied to the digital gas concentration signal. Display the corrected gas standard concentration data; The early warning index is obtained by performing an index-weighted calculation on the standard gas concentration data. The warning index will be displayed and a warning will be issued.

3. The method of claim 2, wherein, The gases include oxygen, carbon dioxide, carbon monoxide and nitric oxide, and their concentration parameters are obtained by infrared oxygen sensor (44), infrared carbon dioxide sensor (45), electrochemical carbon monoxide sensor (46) and electrochemical nitric oxide sensor (47), respectively; the gas temperature digital signal is collected by temperature sensor (32) and the gas pressure digital signal is collected by pressure sensor (33).

4. The method of claim 3, wherein, A single-chip microcomputer (51) is used to acquire gas concentration parameters and convert them into gas concentration digital signals. The gas concentration digital signals are then combined with gas temperature digital signals and pressure digital signals to perform temperature correction and pressure correction.

5. The method of claim 4, wherein, The function for temperature correction of oxygen and carbon dioxide in the microcontroller (51) is as follows: wherein, is the temperature corrected gas concentration percentage value, is the gas concentration percentage value converted from analog to digital and converted from digital to analog output by the infrared oxygen sensor (44) or the infrared carbon dioxide sensor (45), is the temperature sensor (32) output temperature Celsius value, is the calibration temperature Celsius value.

6. The method of claim 4, wherein, The function for temperature correction of carbon monoxide and nitrogen monoxide in the microcontroller (51) is as follows: in, This is the temperature-corrected gas concentration in ppm. The analog-to-digital conversion is used to output the gas concentration (ppm) value after digital-to-analog conversion from the electrochemical carbon monoxide sensor (46) or the electrochemical nitric oxide sensor (47). The temperature sensor (32) outputs a temperature value in degrees Celsius. This is the calibration temperature in degrees Celsius.

7. The method for detecting exhaled breath components according to claim 4, characterized in that, The pressure correction calculation method of the microcontroller (51) is as follows: in, These are the pressure-corrected concentration values ​​for the four gases; These are the temperature-corrected oxygen and carbon dioxide concentration values. , where is the temperature-corrected concentration of carbon monoxide and nitric oxide; P is the pressure value in kilopascals output by the pressure sensor (33).

8. The method for detecting exhaled breath components according to claim 2, characterized in that, The warning index is obtained by performing an exponential weighting operation on the gas standard concentration data using a microcontroller (51). The warning index operation function of the microcontroller (51) for the warning index weighting operation is as follows: in, This is an early warning index; This is the pressure-corrected percentage value of oxygen concentration. This is the percentage value of carbon dioxide concentration after pressure correction; This is the pressure-corrected carbon monoxide concentration in ppm. This is the pressure-corrected nitric oxide concentration in ppm.

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