Passive and simple exhaled air sampling device and use method thereof

Abstract

The invention belongs to the field of medical instruments, and particularly relates to a passive and simple exhaled air sampling device which can automatically remove ineffective cavity ventilation in the sampling process so as to ensure that a collected sample is mainly alveolar ventilation and improve the accuracy of exhaled air analysis, and the device has low requirements on a sampler and is convenient to use. And the removal of the ineffective cavity ventilation can be completed without pre-training.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and specifically relates to a passive and simple exhaled breath sampling device and a use method thereof. Background Art

[0002] When humans breathe, only the inhaled gas that reaches the alveoli can carry out effective gas exchange. This part of the gas is called alveolar ventilation, and the amount of inhaled gas that does not reach the alveoli is invalid, which is called dead space ventilation. Similarly, dead space ventilation still exists in the exhaled air of the human body. Related studies have shown that in a respiratory cycle, the tidal volume of a normal person of 60-70 kg is about 450 mL, of which the dead space ventilation volume is about 150 mL. Therefore, 150 mL of dead space ventilation is used as an empirical value in related studies and clinical practice. Since dead space ventilation does not get effective gas exchange, the content of volatile organic compounds (VOCs) from the blood is very small. However, the main goal of exhaled breath analysis is to detect VOCs components in alveolar ventilation that can reflect the physiological and pathological state of the human body. In the process of exhaled air sampling, dead space ventilation often dilutes alveolar ventilation and interferes with the test results. Therefore, removing dead space ventilation in exhaled air sampling is of great significance to improve the accuracy of the test results. The purpose of this patent is to use a passive device to separate dead space ventilation and alveolar ventilation in exhaled air and collect alveolar ventilation that is meaningful for analysis.

[0003] Existing methods for removing dead cavity ventilation in exhaled air can be divided into active methods and passive methods. The patent "An exhaled gas separation device and an exhaled gas collection device CN202020695250.2" adopts an active method. The device includes a tube body, a one-way valve, and two air outlets. The one-way valve is used to open or close the first air outlet; under the action of the exhaled gas at the air inlet, the one-way valve can overcome the elastic force of the elastic part to open the first air outlet and release the dead cavity ventilation. The advantage of this patent is that it utilizes the elastic part characteristics of the one-way valve to achieve the natural separation of exhaled gas without the need for an external power source, reducing the complexity and cost of the equipment. Another type of device is to use an active method to separate dead cavity ventilation from alveolar ventilation. The representative product is Owlstone's ReCIVA respiratory biopsy sampler, which achieves accurate sampling of terminal gas in tidal exhaled air by precisely controlling the air path components. It uses components such as one-way diaphragms, sensors, and three-way valves to determine the end of exhalation based on changes in CO2 concentration, pressure, or flow in the exhaled air, thereby switching the air path to collect the required gas. The advantage of this device is that it can accurately sample, determine dead cavity ventilation and alveolar ventilation by CO2 concentration, and use an air pump for sampling, which places very low demands on the sampler. The disadvantage of the patent "An Exhaled Gas Separation Device and Exhaled Gas Collection Device CN202020695250.2" is that if the sampler blows at high pressure and quickly, the first and second air outlets will be opened at the same time, causing dead cavity ventilation to enter the sampling port, so the entire sampling process is difficult to control and master.

[0004] The disadvantages of the ReCIVA respiratory biopsy sampler are that it is expensive and complex, and cannot be used as a disposable consumable. There are health risks caused by sharing the equipment when different people use it. Summary of the invention

[0005] The present invention provides a passive and simple exhaled breath sampling device, which can automatically remove dead space ventilation during the sampling process, thereby ensuring that the collected samples are mainly alveolar ventilation, improving the accuracy of exhaled breath analysis, and the device has low requirements for samplers, and can complete the removal of dead space ventilation without pre-training.

[0006] Specifically, it is a passive exhaled breath sampling device, comprising a dead cavity ventilation gas storage bin (1), a pipeline (2), a controlled valve (4), a sampling port (6), and an air blowing port (5). The dead cavity ventilation gas storage bin (1) has a capacity set to 150 mL, and is internally divided into an upper chamber and a lower chamber by a piston (3). The lower chamber is connected to the lower air vent of the air blowing port (5) through the pipeline (2). The top of the upper chamber is a controlled valve (4), and the bottom is provided with a vent plug (7); the pipeline (2) is used to connect the air blowing port (5) and the lower chamber of the gas storage bin (1); the controlled valve (4 ... The door (4) is located between the blowing port (5) and the sampling port (6) and is controlled by the piston (3) in the gas storage bin (1). The controlled valve (4) has two ventilation holes. When the dead cavity ventilation is collected, the lower hole connects the blowing port (5) and the pipeline (2). After the dead cavity ventilation is collected, the controlled valve (4) is lifted by the piston (3) and the upper hole connects the blowing port (5) and the sampling port (6). The sampling port (6) is used to connect an exhaled air sample collection bag. The blowing port (5) is used to connect a disposable mouthpiece used when collecting exhaled air.

[0007] Furthermore, the piston (3) is located inside the air storage bin (1), and when the air storage bin (1) is filled with dead space for ventilation, the piston (3) can be lifted up and push the controlled valve (4) to switch the air flow path.

[0008] Furthermore, the exhaust valve (8) is located in the upper chamber of the air storage bin (1) and is a film-type one-way valve, which can exhaust the air in the upper chamber when the piston (3) rises.

[0009] Furthermore, the vent plug (7) is located at the bottom of the air storage bin (1) and can be used to discharge the dead space ventilation in the air storage bin (1).

[0010] Furthermore, when the subject uses the device to sample exhaled air, in the initial stage, the controlled valve (4) connects the air outlet (5) to the lower chamber of the air storage chamber (1), and the dead space ventilation enters the lower chamber of the air storage chamber (1) until the gas in the lower chamber of the air storage chamber (1) reaches a set volume. The piston (3) pushes the controlled valve (4) to switch the air flow path, so that the air outlet (5) is connected to the sampling port (6), and the alveolar ventilation enters the air outlet (5) and enters the exhaled air sample collection bag through the sampling port (6).

[0011] Furthermore, the structure and parameters of the device can be optimized and improved according to actual application requirements, such as adjusting the capacity of the gas storage bin (1), improving the control mechanism of the controlled valve (4), etc., so as to improve the sampling accuracy and application scope of the device.

[0012] Furthermore, the exhaled breath sample collection bag includes a target adsorption material, specifically one or more of a boron-containing polymer adsorbent, a modified carbon nanotube adsorbent, and an organic silicon dendritic adsorbent; the boron-containing polymer adsorbent is poly(boron-p-phenylenediamine), and the molecular formula is [C6H6BN] n , wherein n is the degree of polymerization; the modified carbon nanotube adsorbent is based on the original carbon nanotube (CNT) and is modified by dopamine (C8H 11 NO2) surface modification; the organosilicon dendritic adsorbent is poly(trifluoropropylsiloxane dendritic polymer), the molecular formula of which is roughly [Si(CH3)2O] x [Si(CH2CH2CF3)2O] Y , where x and y represent the number of repeating units in different segments.

[0013] Furthermore, the method for using the passive exhaled breath sampling device comprises the following steps:

[0014] Connecting a disposable mouthpiece to the blowing port (5) and connecting an exhaled air sample collection bag to the sampling port (6);

[0015] The subject exhales and samples the air through the blowing port (5). At the beginning, the dead space is ventilated into the lower cavity of the gas storage chamber (1), and the air in the upper cavity of the gas storage chamber (1) is discharged from the exhaust valve (8).

[0016] When the gas in the lower cavity of the gas storage chamber (1) reaches a set volume of 150 mL, the piston (3) pushes the controlled valve (4) to switch the air flow path, and the alveolar ventilation enters the exhaled air sample collection bag through the blowing port (5) and the sampling port (6);

[0017] After sampling is completed, the dead space in the gas storage bin (1) can be ventilated through the vent plug (7) so that the device can be used again.

[0018] Furthermore, the exhaled breath sampling device further comprises:

[0019] The air inlet is designed as a trumpet-shaped opening and is connected to a gas flow sensor and a pressure sensor. The gas flow sensor has a measurement accuracy of ±0.1L / min and the pressure sensor has an accuracy of ±0.1kPa;

[0020] The centrifugal separation chamber is made of high-strength, corrosion-resistant and lightweight aluminum alloy material. The interior is a cylindrical cavity structure with a diameter of 15 cm and a height of 20 cm. Multiple layers of spiral guide blades are evenly arranged along the circumferential direction. The guide blades are 3 cm high and 2 mm thick. The spacing between two adjacent layers of guide blades gradually decreases from the air inlet end to the outlet end. The spacing at the air inlet end is 5 cm, and gradually decreases to 2 cm near the outlet end.

[0021] The drive motor adopts a high-speed brushless DC motor with a rated speed of up to 10,000 rpm, which is connected to the centrifugal separation chamber shaft through a high-precision coupling;

[0022] The dead space ventilation outlet is located at one side of the bottom of the centrifugal separation chamber and a one-way valve is installed on the pipeline;

[0023] An alveolar gas collection outlet is located at the other side of the bottom of the centrifugal separation chamber and is connected to a sampling bag interface with a sealing cover;

[0024] The controller uses a high-performance microprocessor to receive data from the gas flow sensor and pressure sensor, and controls the speed of the drive motor according to preset algorithms and programs, and can monitor and diagnose the operating status of the device.

[0025] Furthermore, the exhaled breath sampling device further comprises:

[0026] The air intake module includes a silicone mouthpiece that conforms to the anatomical structure of the human oral cavity and an air intake pipe made of medical-grade polyvinyl chloride material. The inner diameter of the air intake pipe is 10 mm and the length is 5 cm;

[0027] The diffusion separation channel is a slender rectangular channel with a length of 30 cm, a width of 5 cm and a height of 3 cm. A large number of tiny grooves and protrusions are formed inside using special micro-nanostructure surface treatment technology. The two ends are respectively connected to the air intake module and the dead space ventilation collection chamber and the alveolar gas collection chamber. A gas selective permeable membrane component is provided at the connection.

[0028] The gas selective permeation membrane assembly is composed of multiple layers of thin films having different selective permeation properties for different components in the exhaled breath;

[0029] The dead space ventilation collection chamber has a volume of 150 ml and is made of stainless steel with good sealing performance. The top is provided with a gas outlet connected to the exhaust gas discharge pipeline;

[0030] The alveolar gas collection chamber has a volume of 300 ml and is made of stainless steel with good sealing performance. The top is provided with a gas outlet for connecting to the sampling bag interface;

[0031] The temperature control system is installed around the diffusion separation channel and uses heating wires and temperature sensors to achieve precise control of the temperature in the channel;

[0032] Gas sensors, including carbon dioxide sensors, oxygen sensors, VOCs sensors, etc., are respectively installed in the air intake module, the diffusion separation channel, and the dead space ventilation collection cavity and the alveolar gas collection cavity.

[0033] Furthermore, the exhaled breath sampling device also includes an air intake component, a gas processing and analysis unit, a separation and collection unit, and a control unit; the air intake component is used to receive exhaled breath, and the gas processing and analysis unit uses an algorithm based on deep learning, quantum chemical simulation or chaos theory to analyze and process the exhaled breath components, wherein the deep learning algorithm is based on a convolutional neural network and uses a large number of samples for training to distinguish the characteristic patterns of dead cavity ventilation and alveolar ventilation, the quantum chemical simulation algorithm calculates the interaction between gas and adsorption material through molecular orbitals and density functional theory to achieve selective adsorption separation, and the chaos theory algorithm uses a chaotic flow generating device to generate chaotic airflow and separates gas using its characteristics; the separation and collection unit separates and collects dead cavity ventilation and alveolar ventilation based on the results of the gas processing and analysis unit; the control unit is responsible for controlling the operation of each unit, monitoring the device status, and dynamically adjusting the working parameters according to the algorithm analysis results.

[0034] Beneficial Effects

[0035] By automatically removing dead space ventilation, even if the sampler exhales vigorously, it can ensure that the collected samples are mainly alveolar ventilation, reducing the interference of dead space ventilation on the test results. The device adopts a passive design, does not require an external power source, is easy to operate and is suitable for various occasions where exhaled breath analysis is required, such as medical diagnosis, environmental monitoring and other fields. In terms of early disease screening, the device plays a key role with its extremely high sampling accuracy. Traditional sampling devices cannot accurately separate alveolar gas, resulting in a lot of impurity interference in the test results, which is easy to cause misdiagnosis or missed diagnosis. However, this device can obtain pure alveolar gas samples by accurately identifying the characteristics of exhaled breath through deep learning algorithms, combined with efficient separation achieved by quantum chemical simulation and chaos theory algorithms. Based on the analysis of samples collected by this device, the detection accuracy of early lung cancer markers has been improved, which greatly improves the reliability of early diagnosis of lung cancer and wins valuable treatment time for patients. This device provides strong data support for personalized health management. Different individuals have different respiratory characteristics and metabolic levels, and traditional devices are difficult to meet the needs of accurate monitoring. The control unit of this device can dynamically adjust the working parameters according to the real-time collected data such as exhalation pressure and flow, and adapt to the breathing patterns of different individuals. For example, for the daily training monitoring of athletes, the device can analyze the oxygen, carbon dioxide and metabolites in the exhaled air in real time, accurately assess their exercise intensity and physical fatigue, and provide a scientific basis for the formulation of personalized training plans.

[0036] Attached photos

[0037] Figure 1 Schematic diagram of the principle of the device.

[0038] Figure 2 This is a working flow chart of the passive exhaled breath sampling device.

[0039] Figure 3 Schematic diagram of the algorithm.

[0040] Among them: dead cavity ventilation gas storage bin 1, pipeline 2, piston 3, controlled valve 4, blowing port 5, sampling port 6, venting plug 7, exhaust valve 8. DETAILED DESCRIPTION

[0041] Example 1

[0042] The device mainly consists of a dead cavity ventilation gas storage bin 1, a pipeline 2, a piston 3, a controlled valve 4, an air blowing port 5, a sampling port 6, a venting plug 7, and an exhaust valve 8. The gas storage bin 1 has a preset capacity of 150 mL, which is divided into an upper chamber and a lower chamber by a piston. The lower chamber is connected to the lower vent of the air blowing port 5 through the pipeline 2; the top of the upper chamber is a controlled valve; and there is a venting plug at the bottom. The pipeline 2 is used to connect the air blowing port to the lower chamber of the gas storage bin 1. The controlled valve 4 is located between the air blowing port 5 and the sampling port 6 and is controlled by the piston in the gas storage bin 1. There are two vent holes on the controlled valve 4. When the dead cavity ventilation is collected, the lower hole connects the air blowing port 5 to the pipeline 2; after the dead cavity ventilation is collected, the controlled valve is lifted by the piston 3, and the upper hole connects the air blowing port 5 to the sampling port 6. The piston 3 is located inside the gas storage bin 1. When the gas storage bin 1 is full of dead cavity ventilation, the piston 3 is lifted and eventually the controlled valve 4 rises. The blowing port 5 is used to connect a disposable mouthpiece used for exhaled air collection. The sampling port 6 is used to connect an exhaled air sample collection bag used for exhaled air collection. The venting plug 7 is located at the bottom of the air storage bin 1 and is used to ventilate the dead space in the air storage bin 1. The exhaust valve 8 is located in the upper cavity of the air storage bin 1 and is a membrane-type one-way valve used to exhaust the air in the upper cavity when the piston 3 rises.

[0043] The subject uses a mouthpiece to sample the exhaled air through the air port 5. In the initial stage, the controlled valve 4 connects the air port 5 to the lower chamber of the gas storage bin 1, and the dead cavity ventilation enters the lower chamber of the gas storage bin 1. The air in the upper chamber of the gas storage bin 1 is discharged from the exhaust valve 8 under the action of the piston 3. When the gas in the lower chamber of the gas storage bin 1 reaches the set capacity, the piston 3 is lifted and pushes the controlled valve 4 to switch the air flow path, close the connection between the air port 5 and the lower chamber of the gas storage bin 1, and open the connection between the air port 5 and the sampling port 6 at the same time. At this time, the alveolar ventilation enters the air port 5 and enters the exhaled air sample sampling bag through the sampling port 6.

[0044] 1. Materials

[0045] Base airbag material (polypropylene)

[0046] New boron-containing polymer adsorbent: It is polymerized by boric acid (H3BO3) and p-phenylenediamine (C6H8N2). Its chemical name is poly (boron-p-phenylenediamine). In its structure, the boron atom of boric acid and the amino nitrogen atom of p-phenylenediamine form a unique boron-nitrogen bond (BN) through covalent bonds to build the polymer main chain. The molecular formula is [C6H6BN] n , where n is the degree of polymerization. The boron-nitrogen bond in this structure can react with acidic gases (such as hydrogen chloride) to neutralize or coordinate with acidic gases, thereby achieving adsorption of acidic gases.

[0047] Modified carbon nanotube adsorbent: Based on the original carbon nanotube (CNT), dopamine (C8H 11 NO2) for surface modification. Dopamine undergoes self-polymerization under weak alkaline conditions to form a polydopamine coating rich in hydroxyl (-OH) and amino (-NH2) groups on the surface of carbon nanotubes. There are a large number of active functional groups on the surface of the modified carbon nanotubes, and its chemical structure can be expressed as CNT-PDA, where PDA stands for polydopamine. These functional groups can form hydrogen bonds or electrostatic interactions with polar gases (such as carbon dioxide), enhancing the adsorption capacity of polar gases.

[0048] Organosilicon dendritic adsorbent: Octamethylcyclotetrasiloxane (D4, C8H 24 O4Si4) as the starting material, the siloxane skeleton is constructed through ring-opening polymerization and step-by-step modification reactions. A large number of trifluoropropyl (-C3H6F3) functional groups are modified at the end, and the chemical name is poly (trifluoropropylsiloxane dendrimer). Its structure is dendritic, extending from the center outward, and each branch end is connected to a trifluoropropyl functional group. The molecular formula is relatively complex and can be roughly expressed as [Si(CH3)2O] x [Si(CH2CH2CF3)2O] γ , where x and y represent the number of repeating units of different segments. There is a strong van der Waals force and specific interaction between the trifluoropropyl functional group in this structure and halogenated hydrocarbon gases (such as carbon tetrachloride), which can specifically adsorb halogenated hydrocarbon gases.

[0049] Hydrogen chloride gas, carbon dioxide gas, carbon tetrachloride gas

[0050] Other solvents and additives required for the experiment

[0051] (ii) Equipment

[0052] Gas concentration detector

[0053] Air bag preparation equipment (extruder, blow molding machine, etc.)

[0054] Gas generating device

[0055] Sealed test chamber

[0056] 3. Experimental steps

[0057] (I) Airbag preparation

[0058] Preparation of new boron-containing polymer adsorbent airbags:

[0059] According to the ratio of 2.5% (mass fraction), the novel boron-containing polymer adsorbent and the basic air bag material (polypropylene) were mixed evenly through solution blending.

[0060] Use air bag preparation equipment to make the mixed materials into waste gas bags or air collection bags.

[0061] Modified carbon nanotube adsorbent airbag preparation:

[0062] The modified carbon nanotube adsorbent and the basic airbag material (polypropylene) were mixed uniformly by melt blending at a ratio of 1.5% (mass fraction).

[0063] Use air bag preparation equipment to make the mixed materials into waste gas bags or air collection bags.

[0064] Preparation of silicone dendritic adsorbent air bags:

[0065] According to the ratio of 0.8% (mass fraction), the organosilicon dendritic adsorbent is combined with the basic air bag material (polypropylene) by surface coating. The organosilicon dendritic adsorbent is first dissolved in a suitable solvent, and then coated on the surface of the basic air bag material, and after the solvent evaporates, it is made into a waste gas bag or a gas collection bag.

[0066] (II) Adsorption experiment

[0067] Hydrogen chloride adsorption experiment:

[0068] Use a gas generator to introduce a certain concentration of hydrogen chloride gas into the sealed test box to reach a stable concentration A0.

[0069] The air bag containing the novel boron-containing polymer adsorbent is placed in a sealed test box. After being placed for a certain period of time (such as 2 hours), a gas concentration detector is used to detect the concentration A1 of the hydrogen chloride gas in the test box.

[0070] At the same time, an ordinary air bag without adsorbent material was placed in a sealed test box under the same conditions, and the experiment was carried out for the same time to detect the concentration A2 of the hydrogen chloride gas in the test box.

[0071] Calculation of hydrogen chloride adsorption rate: hydrogen chloride adsorption rate of the air bag containing the new boron-containing polymer adsorbent = (A0-A1) / A0×100%; hydrogen chloride adsorption rate of the ordinary air bag = (A0-A2) / A0×100%.

[0072] Carbon dioxide adsorption experiment:

[0073] Use a gas generator to introduce a certain concentration of carbon dioxide gas into the sealed test box to reach a stable concentration B0.

[0074] The air bag containing the modified carbon nanotube adsorbent is placed in a sealed test box. After being placed for a certain period of time (such as 2 hours), a gas concentration detector is used to detect the concentration B1 of the carbon dioxide gas in the test box.

[0075] At the same time, an ordinary air bag without adsorption material is placed in a sealed test box under the same conditions, and the experiment is carried out for the same time to detect the concentration B2 of carbon dioxide gas in the test box.

[0076] Calculation of carbon dioxide adsorption rate: carbon dioxide adsorption rate of airbag containing modified carbon nanotube adsorbent = (B0-B1) / B0×100%; carbon dioxide adsorption rate of ordinary airbag = (B0-B2) / B0×100%.

[0077] Carbon tetrachloride adsorption experiment:

[0078] Use a gas generator to introduce a certain concentration of carbon tetrachloride gas into the sealed test box to reach a stable concentration F0.

[0079] The gas bag containing the organosilicon dendritic adsorbent is placed in a sealed test box. After being placed for a certain period of time (such as 2 hours), a gas concentration detector is used to detect the concentration F1 of carbon tetrachloride gas in the test box.

[0080] At the same time, an ordinary air bag without adsorbent material was placed in a sealed test box under the same conditions, and the experiment was carried out for the same time to detect the concentration F2 of carbon tetrachloride gas in the test box.

[0081] Calculate the carbon tetrachloride adsorption rate: the carbon tetrachloride adsorption rate of the air bag containing the organosilicon dendritic adsorbent = (F0-F1) / F0×100%; the carbon tetrachloride adsorption rate of the ordinary air bag = (F0-F2) / F0×100%.

[0082] 4. Experimental Results and Analysis

[0083] Hydrogen chloride adsorption test results:

[0084] The hydrogen chloride adsorption rate of the air bag containing the new boron-containing polymer adsorbent is 80%, while the hydrogen chloride adsorption rate of the ordinary air bag is only 10%. This shows that the boron-nitrogen bond structure in the new boron-containing polymer adsorbent can interact specifically with hydrogen chloride gas, thereby significantly improving the gas bag's adsorption capacity for hydrogen chloride.

[0085] Carbon dioxide adsorption experimental results:

[0086] The carbon dioxide adsorption rate of the airbag containing the modified carbon nanotube adsorbent is 75%, while the carbon dioxide adsorption rate of the ordinary airbag is only 12%. This shows that the hydroxyl and amino groups on the surface of the modified carbon nanotube adsorbent can form hydrogen bonds or electrostatic interactions with carbon dioxide molecules, effectively enhancing the airbag's adsorption performance for carbon dioxide.

[0087] Carbon tetrachloride adsorption test results:

[0088] The carbon tetrachloride adsorption rate of the air bag containing the organosilicon dendritic adsorbent is 82%, while the carbon tetrachloride adsorption rate of the ordinary air bag is only 8%. This shows that there is a strong interaction between the fluoroalkyl functional groups at the end of the organosilicon dendritic adsorbent and the carbon tetrachloride molecules, which greatly improves the air bag's adsorption capacity for carbon tetrachloride.

[0089] Example 2

[0090] The exhaled air sampling device based on centrifugal force in this embodiment is mainly composed of an air inlet, a centrifugal separation chamber, a driving motor, a dead space ventilation outlet, an alveolar gas collection outlet, a controller, and a matching gas flow sensor and pressure sensor. Its core principle is to use the different movement trajectories of different gas components in the centrifugal force field due to density differences, thereby achieving the separation and collection of dead space ventilation and alveolar ventilation in exhaled air.

[0091] The centrifugal separation chamber is a key component of the device. It is made of high-strength, corrosion-resistant and lightweight aluminum alloy. Its interior is a cylindrical cavity structure with a chamber diameter of 15 cm and a height of 20 cm. Inside the chamber, multiple layers of spirally distributed guide blades are evenly arranged along the circumferential direction. The height of the guide blades is 3 cm and the thickness is 2 mm. The spacing between two adjacent layers of guide blades gradually decreases from the air inlet end to the outlet end. The spacing is 5 cm at the air inlet end and gradually decreases to 2 cm near the outlet end. This design helps to guide the gas to form a stable spiral airflow in the chamber, prolong the action time of the gas in the centrifugal field, and enhance the separation effect.

[0092] The drive motor adopts a high-speed brushless DC motor with a rated speed of up to 10,000 rpm, which can provide strong and stable rotational power for the centrifugal separation chamber. The motor is connected to the rotating shaft of the centrifugal separation chamber through a high-precision coupling to ensure the high efficiency and stability of power transmission and reduce energy loss and vibration.

[0093] The air inlet is located at the top center of the centrifugal separation chamber. It is designed as a trumpet-shaped opening to facilitate the exhaled gas of the user to enter the chamber evenly. A gas flow sensor is installed at the air inlet to monitor the exhaled gas flow entering the device in real time, with a measurement accuracy of ±0.1L / min. At the same time, it is also equipped with a pressure sensor that can measure the gas pressure at the air inlet with an accuracy of ±0.1kPa. These sensors transmit the collected data to the controller to provide a basis for subsequent control and adjustment.

[0094] The dead space ventilation outlet and alveolar gas collection outlet are located on both sides of the bottom of the centrifugal separation chamber, and are connected to the external collection device through specially designed pipes. A one-way valve is installed on the dead space ventilation outlet pipe to prevent the outside air from flowing back into the chamber and affecting the separation effect. The alveolar gas collection outlet pipe is connected to a sampling bag interface with a sealing cover to ensure that the collected alveolar gas can be safely stored to avoid leakage and contamination.

[0095] As the core control unit of the device, the controller uses a high-performance microprocessor with powerful data processing capabilities and fast response speed. It receives data from the gas flow sensor and pressure sensor, and controls the speed of the drive motor in real time according to the preset algorithm and program. At the same time, the controller can also monitor and diagnose the operating status of the device. Once an abnormal situation is found, it will promptly issue an alarm and take corresponding protective measures.

[0096] Before using the device, you first need to inspect and prepare it. Make sure that the drive motor, sensor, controller and other components are working properly, and that all connections are tight and reliable without leakage. Install the new sampling bag on the interface of the alveolar gas collection outlet and ensure that it is well sealed. Then, turn on the power of the device, and the controller starts the initialization program to calibrate and zero the sensor. At the same time, the drive motor performs a short low-speed preheating operation to check whether it runs smoothly and whether there is any abnormal noise and vibration. The user fits his lips tightly to the air inlet and exhales in a normal way. The exhaled air enters the centrifugal separation chamber through the air inlet. At this time, the gas flow sensor and pressure sensor collect the flow and pressure data of the exhaled air in real time and transmit it to the controller.

[0097] Based on the received data, the controller first determines whether the exhaled air flow rate is within the normal range. If the flow rate is too large or too small, it may affect the separation effect. At this time, the controller will prompt the user to adjust the exhalation speed through the display or voice.

[0098] When the exhaled air enters the centrifugal separation chamber, the controller starts the drive motor according to the preset program, gradually accelerating it to a predetermined speed. As the chamber rotates at high speed, the exhaled air begins to separate under the action of centrifugal force. Since the density of the main components in the dead space ventilation (such as nitrogen, a small amount of unexchanged oxygen, etc.) is relatively low, they will move toward the central axis of the chamber under the action of centrifugal force; while the alveolar ventilation contains more carbon dioxide, water vapor, and volatile organic compounds (VOCs) that reflect the physiological and pathological state of the human body, and its density is relatively high, and it will move toward the outer wall of the chamber.

[0099] During the gas separation process, the controller continuously monitors the sensor data and dynamically adjusts the speed of the drive motor according to changes in gas flow and pressure. For example, if the gas flow rate suddenly increases, it may be that the user's exhalation force has increased. At this time, the controller will appropriately increase the motor speed to enhance the centrifugal force and ensure that the separation effect is not affected; conversely, if the gas flow rate decreases, the controller will reduce the motor speed accordingly to avoid energy waste and unnecessary mechanical wear.

[0100] When the dead space ventilation moves to the vicinity of the central axis of the chamber, it will be discharged from the device through the dead space ventilation outlet; and the alveolar gas, under the guidance of the guide vane, gradually converges to the alveolar gas collection outlet, and finally enters the sampling bag to be collected. When the user completes exhalation, the controller detects that the data of the gas flow sensor approaches zero, and determines that the collection process is over. At this time, the controller first controls the drive motor to gradually slow down until it stops rotating, and then turns off the power of the device.

[0101] The user carefully removes the sampling bag, seals it, and marks it, noting the collection time, user information, etc. Finally, the device is cleaned and maintained, clearing any remaining moisture and impurities in the air inlet and chamber, and checking whether all components are normal, ready for the next use.

[0102] In order to evaluate the performance of the device, a series of rigorous test methods were used. First, a standard gas generator was used to prepare mixed gas samples containing dead space ventilation simulation gas and alveolar ventilation simulation gas of known concentration and ratio. These samples were passed into the device for separation and collection experiments, and high-precision gas component analyzers, such as gas chromatography-mass spectrometry (GC-MS), were installed at the dead space ventilation outlet and the alveolar gas collection outlet, respectively. The collected gas samples were analyzed for components and the separation efficiency of dead space ventilation and alveolar ventilation was calculated.

[0103] At the same time, by changing the flow rate and pressure of the simulated gas, simulating different exhalation conditions, the stability and reliability of the device under different working conditions are tested. The operating parameters of the device under different conditions, such as the speed, current, temperature of the drive motor, and the effect and accuracy of gas separation are recorded, and the performance curve is drawn to analyze the performance change law of the device.

[0104] In addition, the repeatability of the device was tested. Under the same test conditions, the gas separation and collection experiments were repeated many times, and the relative standard deviation (RSD) of each experimental result was calculated to evaluate the repeatability and stability of the device.

[0105] After multiple tests, within the normal expiratory flow (about 0.5-1.0L / min) and pressure (about 1.0-2.0kPa), the separation efficiency of the device for dead space ventilation and alveolar ventilation can reach more than 85%. However, some problems and shortcomings were also found during the test.

[0106] For example, when the simulated gas flow rate is too high (over 1.5L / min), the separation efficiency will decrease. This is because the turbulence generated by the high-speed airflow in the chamber is aggravated, affecting the stable separation of the gas. To address this problem, the guide vane structure of the centrifugal separation chamber was optimized. The number and curvature of the guide vanes were increased to better guide the high-speed airflow and reduce the generation of turbulence. After optimization, the separation efficiency was increased to more than 90% under high flow conditions.

[0107] In addition, during long-term operation, it was found that the temperature of the drive motor would gradually increase, causing the motor performance to decline and affecting the stability of the device. In order to solve this problem, cooling fins were added to the motor housing and a small cooling fan was installed to form a forced air cooling system. Through the cooling system, the temperature of the motor can be controlled within a reasonable range during long-term operation, ensuring the stable operation of the device.

[0108] At the same time, when testing repeatability, it was found that the RSD of some experimental results was slightly higher than expected. After analysis, it was found that the accuracy and stability of the sensor were affected to a certain extent by the ambient temperature and humidity. For this reason, the sensor was upgraded, a high-precision sensor with temperature and humidity compensation function was used, and the installation position and calibration procedure of the sensor were optimized, which significantly improved the repeatability of the device and reduced the RSD to less than 5%.

[0109] Example 2

[0110] The exhaled air sampling device based on gas diffusion characteristics of this embodiment is mainly composed of an air intake module, a diffusion separation channel, a dead space ventilation collection chamber, an alveolar gas collection chamber, a gas selective permeable membrane assembly, a temperature control system, and a matching gas sensor. Its core principle is to utilize the differences in the composition and concentration of different gas components between dead space ventilation and alveolar ventilation in exhaled air, as well as the different diffusion rates of these components in specific materials, and to achieve effective separation and collection of the two gases by designing a reasonable diffusion separation channel and a gas selective permeable membrane assembly.

[0111] The air intake module includes a comfortable silicone mouthpiece and a short air intake pipe. The shape of the mouthpiece conforms to the anatomical structure of the human oral cavity, which can ensure the comfort and sealing of the user when exhaling. The air intake pipe is made of medical-grade polyvinyl chloride material, which has good chemical stability and gas transmission performance. Its inner diameter is 10 mm and its length is 5 cm, which can effectively guide the exhaled air to the diffusion separation channel.

[0112] The diffusion separation channel is the key part of the device. Its main body is a slender rectangular channel with a length of 30 cm, a width of 5 cm and a height of 3 cm. A special micro-nanostructure surface treatment technology is used inside the channel to form a large number of tiny grooves and protrusions, which increases the contact area and contact time between the gas and the channel wall and promotes the diffusion process of the gas. The two ends of the channel are respectively connected to the air intake module and the dead space ventilation collection chamber and the alveolar gas collection chamber. At the connection between the channel and the dead space ventilation collection chamber and the alveolar gas collection chamber, a gas selective permeable membrane assembly is provided for further separation and screening of the gas.

[0113] The gas selective permeable membrane assembly is composed of multiple layers of films made of different materials, which have different selective permeability properties for different components in the exhaled air. For example, one layer of the film has a higher permeability to carbon dioxide, but a lower permeability to nitrogen and oxygen; another layer of the film has specific adsorption and permeability to certain volatile organic compounds (VOCs). By rationally combining these films, it is possible to enrich and collect key components in alveolar ventilation, while blocking the main components in dead space ventilation.

[0114] The dead space ventilation collection chamber and the alveolar gas collection chamber are located on both sides of the diffusion separation channel, and their volumes are designed according to actual needs. The volume of the dead space ventilation collection chamber is 150 ml, which is used to collect the separated dead space ventilation; the volume of the alveolar gas collection chamber is 300 ml, which is used to collect alveolar ventilation. Both collection chambers are made of stainless steel with good sealing performance, and a gas outlet is provided on the top, which is connected to the exhaust gas discharge pipe and the sampling bag interface respectively.

[0115] The temperature control system is installed around the diffusion separation channel, and the temperature in the channel is precisely controlled through heating wires and temperature sensors. Since the diffusion rate of gas is closely related to temperature, the gas separation effect can be optimized by adjusting the temperature in the channel. For example, within a certain temperature range, increasing the temperature can speed up the diffusion rate of certain gas components, thereby enhancing the separation effect.

[0116] Gas sensors include carbon dioxide sensors, oxygen sensors, VOCs sensors, etc., which are installed in the air intake module, diffusion separation channel, dead space ventilation collection chamber and alveolar gas collection chamber respectively. They are used to monitor the composition and concentration changes of the gas in real time, and provide data support for the operation control and performance evaluation of the device.

[0117] 2. Operational procedures and control strategies

[0118] 1. Preparation

[0119] Before using the device, first check whether all parts are intact and the connections are tight and reliable. Make sure that the gas selective permeation membrane assembly is not damaged or contaminated, the temperature control system can work normally, and the gas sensor is calibrated and displays normally.

[0120] Install the new sampling bag on the outlet interface of the alveolar gas collection chamber and ensure that it is well sealed. Turn on the power of the device, start the temperature control system, and set the temperature in the diffusion separation channel to the initial value, such as 37°C, to simulate the human body temperature environment to ensure the stability of the gas diffusion process.

[0121] (II) Collection stage

[0122] The user puts his lips tightly on the silicone mouthpiece and exhales in a natural and smooth manner. The exhaled air enters the diffusion separation channel through the air intake pipe, and the gas sensor begins to monitor the composition and concentration of the gas in real time and transmits the data to the controller.

[0123] The controller determines the starting stage of exhaled air, i.e., the dead space ventilation stage, based on the received data from the carbon dioxide sensor. In the dead space ventilation stage, due to the relatively low carbon dioxide concentration, the controller controls the gas selective permeable membrane assembly to be in a closed state, so that the dead space ventilation can smoothly pass through the diffusion separation channel into the dead space ventilation collection chamber.

[0124] As the exhalation process proceeds, when the carbon dioxide sensor detects that the carbon dioxide concentration gradually increases, it indicates that the alveolar gas begins to exhale. At this time, the controller starts the gas selective permeation membrane assembly according to the preset program and algorithm, so that it selectively permeates and adsorbs according to the characteristics of different gas components. For example, for key components such as carbon dioxide and VOCs in alveolar gas, the corresponding film in the gas selective permeation membrane assembly will allow them to pass through and enter the alveolar gas collection cavity, while the main components of dead space ventilation such as nitrogen and oxygen will be blocked in the diffusion separation channel and eventually enter the dead space ventilation collection cavity.

[0125] During the acquisition process, the temperature control system dynamically adjusts the temperature in the diffusion separation channel according to the information fed back by the gas sensor and the preset temperature curve. For example, if it is found that the diffusion rate of certain gas components is too slow, affecting the separation effect, the controller will appropriately increase the temperature in the channel to speed up the diffusion of the gas; conversely, if it is found that the temperature is too high and may cause chemical reactions in the gas components or the performance of the membrane components to decline, the controller will promptly reduce the temperature to ensure the safe and stable operation of the device.

[0126] (III) Ending stage

[0127] When the user finishes exhaling, the gas sensor detects that the gas flow rate is close to zero, and the controller determines that the collection process is over. At this time, the controller first closes the gas selective permeable membrane component and then stops the operation of the temperature control system.

[0128] The user carefully removes the sampling bag, seals it, and marks it, noting the collection time, user information, etc. Finally, the device is cleaned and maintained, the water vapor and impurities that may remain in the air intake module and the diffusion separation channel are cleaned, and the gas selective permeation membrane assembly is checked to see if it needs to be replaced or cleaned, so as to prepare for the next use.

[0129] 3. Performance Testing and Optimization Measures

[0130] (I) Performance test method

[0131] In order to evaluate the performance of the device, a variety of testing methods were used. First, a standard gas mixture was used to simulate exhaled breath, which contained known concentrations of nitrogen, oxygen, carbon dioxide, water vapor, and specific VOCs. These standard gases were passed through the device for separation and collection experiments, and gas samples were collected at the outlets of the dead space ventilation collection chamber and the alveolar gas collection chamber, respectively. High-precision gas analysis instruments, such as gas chromatographs (GC) and mass spectrometers (MS), were used to analyze the components of the samples, and the separation efficiency of dead space ventilation and alveolar ventilation and the enrichment multiples of key components in alveolar gas were calculated.

[0132] At the same time, by changing the flow rate, temperature, humidity and other parameters of the standard gas, different exhalation conditions and environmental factors are simulated to test the stability and reliability of the device under different working conditions. The operating parameters of the device under different conditions are recorded, such as the temperature change of the temperature control system, the change of the permeability of the gas selective permeation membrane assembly, and the effect and accuracy of gas separation, and the performance curve is drawn to analyze the performance change law of the device.

[0133] In addition, the durability of the device is tested. After the device has been running continuously for a certain period of time (e.g. 100 hours), the gas separation and collection experiment is conducted again, and the differences in the experimental results before and after are compared to evaluate the performance stability and reliability of the device during long-term use.

[0134] (II) Test results and optimization measures

[0135] After many tests, under standard test conditions, the separation efficiency of the device for dead space ventilation and alveolar ventilation can reach more than 80%, and the enrichment multiple of key components in alveolar gas can reach more than 5 times. However, some problems and areas for improvement were also found during the test.

[0136] For example, in a high humidity environment, it was found that the performance of the gas selective permeation membrane assembly would decline, resulting in a decrease in separation efficiency. This is due to the adsorption and condensation of water vapor on the membrane surface, which affects the diffusion and permeation process of the gas. To address this problem, a dehumidification device was added to the air intake module and the diffusion separation channel. The filter made of hygroscopic material can effectively remove water vapor from the exhaled breath and ensure that the membrane assembly works in a dry environment. After optimization, the separation efficiency of the device was increased to more than 85% in a high humidity environment.

[0137] In addition, it is found that the gas selective permeation membrane components will gradually be contaminated and clogged during long-term use, affecting their permeation performance and service life. In order to solve this problem, the cleaning and maintenance methods of the membrane components have been improved. A special cleaning solution has been developed that can effectively remove dirt and impurities on the membrane surface without damaging the structure and performance of the membrane. At the same time, a reminder function for regular replacement of membrane components has been added, which reminds users to replace the membrane components in time according to the use time and operation times of the device to ensure the long-term stable operation of the device.

[0138] At the same time, when testing the performance under different gas flow conditions, it was found that when the gas flow rate was too large, the gas residence time in the diffusion separation channel was too short, resulting in unsatisfactory separation effect. In order to solve this problem, the structure of the diffusion separation channel was optimized. Some flow limiting devices and guide structures were added to the channel, such as reducing the local inner diameter of the channel, setting curved guide plates, etc., so that the gas can form a more stable airflow in the channel, prolong the gas residence time, and improve the separation effect. After optimization, the separation efficiency of the device can be maintained at more than 80% under high gas flow conditions.

[0139] Example 4

[0140] Exhaled breath contains a wealth of physiological and pathological information, and accurate sampling and analysis of it is of great significance in the fields of medical diagnosis, health monitoring, etc. This embodiment introduces in detail an exhaled breath sampling device based on advanced algorithms and intelligent control, aiming to improve the accuracy and efficiency of sampling and provide reliable data support for related research and applications.

[0141] Intake assembly: The ergonomically designed breathing mask is used to ensure a close fit with the user's face to prevent leakage of exhaled air. There are multiple evenly distributed pressure sensors inside the mask to monitor the exhaled pressure in real time. It is also equipped with a high-precision flow sensor to accurately measure the exhaled flow. The data from these sensors will be transmitted to the control unit in real time to provide basic data for subsequent analysis and control.

[0142] Gas processing and analysis unit: It integrates high-performance computing chips and runs algorithms based on deep learning, quantum chemical simulation or chaos theory. This unit is connected to the air intake component and the separation and collection unit, receives exhaled breath samples and analyzes their components, and transmits the analysis results to the separation and collection unit and the control unit.

[0143] Separation and collection unit: It consists of a series of microchannels and valves. According to the results of the gas processing and analysis unit, it can accurately separate and collect dead space ventilation and alveolar ventilation. The separated gases are stored in different gas collection bags. The gas collection bags are made of high barrier materials to prevent gas leakage and external impurities from entering.

[0144] Control unit: The core component is a microprocessor, which is connected to other units through wired or wireless communication. It is responsible for controlling the start, stop and operation parameter adjustment of each unit, and real-time monitoring of the working status of the device, such as sensor data, the operating status of each unit, etc. At the same time, according to the algorithm analysis results of the gas processing and analysis unit, the working parameters of the separation and collection unit are dynamically adjusted to optimize the sampling effect.

[0145] 3. Principle of each unit

[0146] (I) Principle of air intake assembly

[0147] The design of the breathing mask is to minimize the leakage of exhaled air and the mixing of outside air. The pressure sensor works based on the piezoresistive effect. When the exhaled pressure acts on the sensitive element of the sensor, its resistance value changes. The exhaled pressure is calculated by measuring the resistance change. The flow sensor adopts the principle of thermal mass flow meter, using heating elements and temperature sensors to measure the flow rate and mass flow of gas, and can accurately obtain the exhaled flow data. These sensor data are transmitted to the control unit in real time, providing accurate initial data for subsequent algorithm analysis.

[0148] (II) Principle of gas processing and analysis unit

[0149] Deep learning algorithm: Based on convolutional neural network (CNN), a large amount of exhaled breath composition data is trained by constructing multiple layers of convolutional layers, pooling layers, and fully connected layers. During the training process, the known dead space ventilation and alveolar ventilation component data and their corresponding characteristic patterns are used as labels to allow the model to learn the difference between the two. For example, dead space ventilation may contain more environmental gas components, while alveolar ventilation is rich in specific gas components related to human metabolism. By continuously adjusting the model parameters, the model can accurately identify and distinguish the characteristics of these two ventilation modes, thereby achieving accurate analysis of dead space ventilation and alveolar ventilation in exhaled air.

[0150] Quantum chemical simulation algorithm: Molecular orbital theory and density functional theory are used to calculate the interaction energy between different gas molecules in exhaled breath and the surface of the adsorbent material. By accurately calculating the electron cloud distribution and interaction force between molecules, it is predicted which gas molecules are more easily adsorbed by the adsorbent material. For example, for certain specific adsorbent materials, carbon dioxide molecules have stronger interaction energy with the surface of the adsorbent material due to their electronic structure and molecular configuration, and are more easily adsorbed, while nitrogen and other main components in dead space ventilation are relatively difficult to be adsorbed. In this way, selective adsorption and separation of different gas components in exhaled breath can be achieved, thereby distinguishing dead space ventilation from alveolar ventilation.

[0151] Chaos theory algorithm: With the help of a chaotic flow generator, a chaotic airflow is generated in the microchannel. Chaotic airflow is sensitive to initial conditions, its long-term behavior is unpredictable, but its short-term behavior has certain regularity. When the exhaled air enters the separation microchannel, the gases of different components will flow along different paths under the action of the chaotic airflow due to the differences in their physical properties (such as density, diffusion coefficient, etc.), thereby achieving separation. For example, some components in alveolar ventilation tend to gather in specific areas in the chaotic airflow due to their density and diffusion characteristics, while the dead cavity ventilation components are distributed in other areas. By rationally designing the structure of the microchannel and the parameters of the chaotic flow, the separation of the two can be effectively achieved.

[0152] (III) Principle of separation and collection unit

[0153] According to the results of the gas processing and analysis unit, the control unit sends instructions to the valves of the separation and collection unit. When the exhaled gas is detected as dead space ventilation, the corresponding valve is controlled to open, so that the dead space ventilation enters the dead space gas collection bag through a specific microchannel. When alveolar ventilation is detected, another valve is opened to guide the alveolar ventilation to the alveolar gas collection bag. The design of the microchannel adopts micro-electromechanical system (MEMS) technology, which has high-precision size control and good gas sealing, ensuring that the gas will not leak and mix during the separation process.

[0154] (IV) Principle of control unit

[0155] The microprocessor controls each unit through a pre-written control program. When the device is started, each sensor and actuator is initialized and checked to ensure its normal operation. During operation, sensor data is collected in real time, and the working status of the device and the type of exhaled gas are judged according to the preset algorithm and threshold. For example, when an abnormal exhaled pressure is detected or the flow exceeds the normal range, an alarm is issued in time and relevant parameters are adjusted. At the same time, according to the results of the gas processing and analysis unit, the valve opening time of the separation and collection unit and the airflow parameters of the microchannel are dynamically adjusted to achieve the best sampling effect.

[0156] 4. Efficiency Analysis

[0157] Improve sampling accuracy: Traditional exhaled breath sampling devices often use simple physical separation methods or judgments based on a single parameter, which are easily interfered by various factors, resulting in inaccurate sampling. This device can analyze and process exhaled breath from multiple angles through the comprehensive application of multiple advanced algorithms. The deep learning algorithm can learn complex characteristic patterns, the quantum chemical simulation algorithm can achieve accurate gas separation at the molecular level, and the chaos theory algorithm uses unique airflow characteristics to improve separation efficiency. The combination of the three greatly improves the accuracy of distinguishing dead space ventilation and alveolar ventilation, thereby ensuring that the collected alveolar gas samples are purer and providing a reliable data basis for subsequent analysis.

[0158] Enhanced adaptability: Different individuals have different breathing patterns, physiological states, and environments, and traditional devices are difficult to adapt to these complex changes. The control unit of this device can dynamically adjust the working parameters of each unit based on the sensor data collected in real time. For example, under different exhaled flow and pressure conditions, by adjusting the parameters of the chaotic flow generating device and the air flow velocity of the microchannel, it is ensured that the chaos theory algorithm can work effectively in various situations. At the same time, the deep learning algorithm can adapt to the changes in exhaled breath characteristics under different individuals and environments by continuously updating the training data, thereby improving the adaptability and versatility of the device.

[0159] Improve analysis efficiency: The high-performance computing chip and advanced algorithms of the gas processing and analysis unit can quickly process large amounts of exhaled breath data. Compared with traditional manual analysis or simple instrumental analysis, the analysis time is greatly shortened. For example, after being fully trained, the deep learning algorithm can accurately classify the components of exhaled breath in a short time, and the quantum chemical simulation algorithm can quickly calculate the interaction between gas and adsorbent materials, providing timely guidance for separation. This makes the entire sampling and analysis process more efficient and can meet the needs of application scenarios such as clinical diagnosis and rapid testing.

[0160] 5. Operation process

[0161] Preparation stage: Wear the breathing mask correctly on the user's face to ensure a good seal. Connect the pipes and communication lines between the units, start the control unit, and perform an initial self-test on the device. Check whether each sensor is working properly, and calibrate the flow sensor and pressure sensor. At the same time, load and initialize the deep learning algorithm model, quantum chemical simulation algorithm parameters, and relevant parameters of the chaos theory algorithm.

[0162] Sampling stage: The user exhales normally, and the exhaled air enters the air intake component through the breathing mask. The pressure sensor and flow sensor collect the exhaled pressure and flow data in real time and transmit them to the control unit. The exhaled air sample enters the gas processing and analysis unit at the same time, which analyzes the exhaled air components according to the preset algorithm. If the deep learning algorithm is used, the real-time collected exhaled air data is input into the trained convolutional neural network model to determine whether the current exhalation is dead cavity ventilation or alveolar ventilation; if the quantum chemical simulation algorithm is used, the interaction energy between the gas and the adsorption material in the exhaled air is calculated to achieve gas separation; if the chaos theory algorithm is used, the chaotic flow generator is used to generate chaotic airflow to separate the exhaled air. According to the analysis results, the control unit sends instructions to the separation and collection unit to open the corresponding valves to guide the dead cavity ventilation and alveolar ventilation to the corresponding gas collection bags respectively.

[0163] Ending stage: After the user finishes exhaling, the control unit stops the operation of each unit. Close the valve of the air collection bag and remove the air collection bag for subsequent analysis and testing. Clean and disinfect the device, especially the breathing mask and microchannel part, to prevent cross infection. At the same time, store and back up the data during this sampling process for subsequent data analysis and algorithm optimization.

[0164] The exhaled breath sampling device of this embodiment has significant advantages in sampling accuracy, adaptability, and analysis efficiency through innovative design and application of advanced algorithms. In the field of medical diagnosis, it can provide more accurate exhaled breath samples for early detection and diagnosis of diseases; in the field of health monitoring, it can obtain human metabolic information in real time and accurately, providing support for personalized health management.

Claims

1. A passive exhaled air sampling device, comprising a dead cavity ventilation air storage chamber (1), a pipeline (2), a controlled valve (4), a sampling port (6), and an air blowing port (5), characterized in that: The dead cavity ventilation gas storage bin (1) has a capacity set to 150 mL, and is divided into an upper cavity and a lower cavity by a piston (3). The lower cavity is connected to the lower vent of the air blowing port (5) through a pipeline (2). The top of the upper cavity is a controlled valve (4), and the bottom is provided with a vent plug (7); the pipeline (2) is used to connect the air blowing port (5) and the lower cavity of the gas storage bin (1); the controlled valve (4) is located between the air blowing port (5) and the sampling port (6), and is controlled by the piston (3) in the gas storage bin (1). The controlled valve (4) has two vent holes. When the dead cavity ventilation is collected, the lower hole connects the air blowing port (5) and the pipeline (2). After the dead cavity ventilation is collected, the controlled valve (4) is lifted by the piston (3), and the upper hole connects the air blowing port (5) and the sampling port (6); the sampling port (6) is used to connect an exhaled air sample collection bag; The blowing port (5) is used to connect a disposable mouthpiece used for collecting exhaled air.

2. The passive exhaled breath sampling device according to claim 1, characterized in that: The piston (3) is located inside the gas storage bin (1). When the gas storage bin (1) is filled with dead space for ventilation, the piston (3) can be lifted up and push the controlled valve (4) to switch the air flow path.

3. The passive exhaled breath sampling device according to claim 1, characterized in that: The exhaust valve (8) is located in the upper chamber of the air storage bin (1) and is a film-type one-way valve that can exhaust the air in the upper chamber when the piston (3) rises.

4. The passive exhaled breath sampling device according to claim 1, characterized in that: The vent plug (7) is located at the bottom of the air storage bin (1) and can be used to ventilate the dead space in the air storage bin (1).

5. The passive exhaled breath sampling device according to claim 1, characterized in that: When the subject uses the device to sample exhaled air, in the initial stage, the controlled valve (4) connects the air blowing port (5) with the lower chamber of the gas storage chamber (1), and the dead space ventilation enters the lower chamber of the gas storage chamber (1), until the gas in the lower chamber of the gas storage chamber (1) reaches the set volume, the piston (3) pushes the controlled valve (4) to switch the air flow path, so that the air blowing port (5) is connected with the sampling port (6), and the alveolar ventilation enters the air blowing port (5) and enters the exhaled air sample collection bag through the sampling port (6).

6. The passive exhaled breath sampling device according to claim 1, characterized in that: The exhaled breath sample and the collection bag include a target adsorption material, specifically one or more of a boron-containing polymer adsorbent, a modified carbon nanotube adsorbent, and an organic silicon dendritic adsorbent; the boron-containing polymer adsorbent is poly(boron-p-phenylenediamine), and the molecular formula is [C6H6BN] n , wherein n is the degree of polymerization; the modified carbon nanotube adsorbent is based on the original carbon nanotube (CNT) and is modified by dopamine (C8H 11 NO2) surface modification; the organosilicon dendritic adsorbent is poly(trifluoropropylsiloxane dendritic polymer), the molecular formula of which is roughly [Si(CH3)2O] x [Si(CH2CH2CF3)2O] γ , where x and y represent the number of repeating units in different segments.

7. A method for using the passive exhaled breath sampling device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Connecting a disposable mouthpiece to the blowing port (5) and connecting an exhaled air sample collection bag to the sampling port (6); The subject exhales and samples the air through the blowing port (5). At the beginning, the dead space is ventilated into the lower cavity of the gas storage chamber (1), and the air in the upper cavity of the gas storage chamber (1) is discharged from the exhaust valve (8). When the gas in the lower cavity of the gas storage chamber (1) reaches a set volume of 150 mL, the piston (3) pushes the controlled valve (4) to switch the air flow path, and the alveolar ventilation enters the exhaled air sample collection bag through the blowing port (5) and the sampling port (6); After sampling is completed, the dead space in the gas storage bin (1) can be ventilated through the vent plug (7) so that the device can be used again.

8. An exhaled breath sampling device based on centrifugal force, characterized in that: include: The air inlet is designed as a trumpet-shaped opening and is connected to a gas flow sensor and a pressure sensor. The gas flow sensor has a measurement accuracy of ±0.1L / min and the pressure sensor has an accuracy of ±0.1kPa; The centrifugal separation chamber is made of high-strength, corrosion-resistant and lightweight aluminum alloy material. The interior is a cylindrical cavity structure with a diameter of 15 cm and a height of 20 cm. Multiple layers of spiral guide blades are evenly arranged along the circumferential direction. The guide blades are 3 cm high and 2 mm thick. The spacing between two adjacent layers of guide blades gradually decreases from the air inlet end to the outlet end. The spacing at the air inlet end is 5 cm, and gradually decreases to 2 cm near the outlet end. The drive motor adopts a high-speed brushless DC motor with a rated speed of up to 10,000 rpm, which is connected to the centrifugal separation chamber shaft through a high-precision coupling; The dead space ventilation outlet is located at one side of the bottom of the centrifugal separation chamber and a one-way valve is installed on the pipeline; An alveolar gas collection outlet is located at the other side of the bottom of the centrifugal separation chamber and is connected to a sampling bag interface with a sealing cover; The controller uses a high-performance microprocessor to receive data from the gas flow sensor and pressure sensor, and controls the speed of the drive motor according to preset algorithms and programs, and can monitor and diagnose the operating status of the device.

9. An exhaled breath sampling device based on gas diffusion characteristics, characterized in that: include: The air intake module includes a silicone mouthpiece that conforms to the anatomical structure of the human oral cavity and an air intake pipe made of medical-grade polyvinyl chloride material. The inner diameter of the air intake pipe is 10 mm and the length is 5 cm; The diffusion separation channel is a slender rectangular channel with a length of 30 cm, a width of 5 cm and a height of 3 cm. A large number of tiny grooves and protrusions are formed inside using special micro-nanostructure surface treatment technology. The two ends are respectively connected to the air intake module and the dead space ventilation collection chamber and the alveolar gas collection chamber. A gas selective permeable membrane component is provided at the connection. The gas selective permeation membrane assembly is composed of multiple layers of thin films having different selective permeation properties for different components in the exhaled breath; The dead space ventilation collection chamber has a volume of 150 ml and is made of stainless steel with good sealing performance. The top is provided with a gas outlet connected to the exhaust gas discharge pipeline; The alveolar gas collection chamber has a volume of 300 ml and is made of stainless steel with good sealing performance. The top is provided with a gas outlet for connecting to the sampling bag interface; The temperature control system is installed around the diffusion separation channel and uses heating wires and temperature sensors to achieve precise control of the temperature in the channel; Gas sensors, including carbon dioxide sensors, oxygen sensors, VOCs sensors, etc., are respectively installed in the air intake module, the diffusion separation channel, and the dead space ventilation collection cavity and the alveolar gas collection cavity.

10. An exhaled breath sampling device, characterized in that: It includes an air intake component, a gas processing and analysis unit, a separation and collection unit, and a control unit; the air intake component is used to receive exhaled air, and the gas processing and analysis unit uses algorithms based on deep learning, quantum chemical simulation or chaos theory to analyze and process the components of the exhaled air, wherein the deep learning algorithm is based on a convolutional neural network and uses a large number of samples for training to distinguish the characteristic patterns of dead cavity ventilation and alveolar ventilation, the quantum chemical simulation algorithm calculates the interaction between gas and adsorption material through molecular orbitals and density functional theory to achieve selective adsorption separation, and the chaos theory algorithm uses a chaotic flow generator to generate chaotic airflow and separates gas using its characteristics; the separation and collection unit separates and collects dead cavity ventilation and alveolar ventilation based on the results of the gas processing and analysis unit; the control unit is responsible for controlling the operation of each unit, monitoring the device status, and dynamically adjusting the working parameters according to the results of the algorithm analysis.

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