A device and method for detecting hydrogen and methane concentrations in exhaled breath

Abstract

The application discloses a kind of hydrogen and methane concentration detection device and correction method in exhaled gas related to gas analysis technical field.The shell is provided with exhaust cavity and intake cavity in the shell, the shell is fixedly connected with intake pipe, the exhaust cavity is fixedly connected with waste storage cylinder in the shell, and the intake pipe is communicated with the lower side of the waste storage cylinder;Exhaust platen is slidably connected in the waste storage cylinder, exhaust sealing ring is fixedly connected between the exhaust platen and the waste storage cylinder, and the intake pipe is fixedly connected with connecting pipe;Transfer cylinder is fixedly connected in the intake cavity, and oxygen sensor and detection sensor are installed in the shell.The present application uses waste storage cylinder to collect and isolate the first section of gas flowing in the shell, and uses the second section of gas flowing in the shell as sample gas for detection, to reduce the influence of air in the gas guide pipe and the shell and the dead cavity gas on the hydrogen and methane concentration in the sample gas, and to improve the detection accuracy.

Description

Technical Field

[0001] This invention relates to the field of gas analysis technology, and in particular to a device and calibration method for detecting hydrogen and methane concentrations in exhaled gas. Background Technology

[0002] Exhaled breath testing is a non-invasive medical diagnostic method that assesses health status or detects specific diseases by analyzing the composition of exhaled breath. Specifically, using a gas analyzer to detect the concentration of hydrogen and methane in exhaled breath can be used to diagnose small intestinal bacterial overgrowth, lactose intolerance, and pancreatic exocrine function. Currently, exhaled breath testing involves connecting a disposable filter to a gas analyzer via an air tube. The patient blows air into the analyzer, and the exhaled breath serves as a sample gas, passing through sensors inside the analyzer to detect the concentration of hydrogen and methane. Because the air tube and the gas analyzer are initially... Air is present in the sample gas. Exhaled air consists of alveolar gas (gas exchanged within the alveoli) and dead space gas (gas in the respiratory tract from the nasal cavity to the terminal bronchioles, which does not participate in gas exchange between the alveoli and blood). Hydrogen and methane enter the exhaled air through the alveoli. Therefore, the presence of air in the air delivery tube and inside the gas analyzer, as well as dead space gas, reduces the concentration of hydrogen and methane in the sample gas. Consequently, after the sample gas passes through the gas analyzer, the average concentration of hydrogen and methane measured by the sensors inside the analyzer is lower than the actual concentration, resulting in low detection accuracy. Summary of the Invention

[0003] This invention provides a device and calibration method for detecting hydrogen and methane concentrations in exhaled gas, overcoming the shortcomings of existing methods that reduce the concentration of hydrogen and methane in the sample gas due to the presence of air in the air delivery tube and gas analyzer, as well as dead space gas, during exhaled gas detection, resulting in low detection accuracy.

[0004] The technical solution of the present invention is: a device for detecting the concentration of hydrogen and methane in exhaled gas, comprising: The housing has a waste discharge chamber and an air intake chamber. An air intake pipe is fixedly connected to the housing. A waste storage cylinder is fixedly connected to the waste discharge chamber. The air intake pipe is connected to the lower side of the waste storage cylinder. A waste discharge pressure plate is slidably connected inside the waste storage cylinder, and a waste discharge sealing ring is fixedly connected between the waste discharge pressure plate and the waste storage cylinder. The air inlet pipe is fixedly connected to and connected to a connecting pipe. A transfer cylinder is fixedly connected to the air inlet chamber, and its lower side is connected to the connecting pipe. A detection pipe connected to the outside is fixedly connected to and connected to the lower side of the transfer cylinder. An oxygen sensor and a detection sensor are installed inside the housing. The detection pipe is connected to the oxygen sensor and the detection sensor in sequence. A switching component, located inside the connecting pipe, is used to control the connection state between the air intake pipe and the connecting pipe.

[0005] Furthermore, the switching component includes: A retaining ring is fixed to the side of the connecting pipe near the air intake pipe; A fixing bracket is fixedly connected to the connecting pipe. The fixing bracket is fixedly connected to a sealing disc that contacts the fixing ring by a tension spring. The fixing bracket and the sealing disc are located on both sides of the fixing ring, and the fixing bracket is located on the side of the sealing disc closer to the air intake pipe. A conversion plate is slidably connected to the waste storage cylinder, which is provided with a waste discharge hole. The conversion plate is used to seal the waste discharge hole and the connection between the air inlet pipe and the waste storage cylinder in sequence. The housing is provided with a first through hole that connects the waste discharge chamber to the outside.

[0006] Furthermore, the sealing disc is magnetic, and the retaining ring is made of a soft magnetic material.

[0007] Furthermore, it also includes: The mounting bracket is fixed to the upper side of the waste storage cylinder. The mounting bracket is rotatably connected to a threaded knob. The threaded knob is threadedly connected to a pressing member that is slidably connected to the mounting bracket. The pressing member is used to limit the range of movement of the waste discharge plate.

[0008] Furthermore, it also includes: A transfer pressure plate is slidably connected inside the transfer cylinder. The transfer pressure plate is fixedly connected to and connected to a pressure relief valve. A transfer sealing ring is fixedly connected between the transfer pressure plate and the transfer cylinder. A sealing element is slidably connected inside the transfer cylinder and fixedly connected to the sealing disc. The sealing element is used to block the connection between the transfer cylinder and the detection tube.

[0009] Furthermore, it also includes: A backflush cylinder is fixedly connected to the air inlet chamber. An air extraction pipe is provided on the lower side of the backflush cylinder. An air extraction one-way valve is fixedly connected inside the air extraction pipe. The housing is provided with a second through hole that connects the air inlet chamber to the outside. An exhaust pipe is fixedly connected to and connected to the lower side of the backflush cylinder, and is connected to the connecting pipe near the intake pipe. The connection point between the exhaust pipe and the connecting pipe is located on the side of the sealing plate away from the fixed frame. An exhaust one-way valve is fixedly connected inside the exhaust pipe. A back-jet plate is slidably connected inside the back-jet cylinder, and a bellows is fixedly connected between the back-jet plate and the back-jet cylinder; A triggering component, disposed on the recoil cylinder, is used to control the movement sequence of the recoil pressure plate and the transfer pressure plate.

[0010] Furthermore, the first through hole and the second through hole on the housing are located on opposite sides of the housing, respectively.

[0011] Furthermore, the triggering component includes: A support member, fixedly connected to the transfer pressure plate, is used to press against the recoil pressure plate; A connecting frame is fixed to the side of the recoil cylinder near the transfer cylinder. The connecting frame is rotatably connected to a Z-shaped frame, and a torsion spring is fixed between the two. The Z-shaped frame is used to limit the recoil pressure plate, and the transfer pressure plate is used to squeeze the Z-shaped frame.

[0012] Furthermore, it also includes: A connecting ring is fixed to the intermediate sealing ring. A magnetic suction plate is fixed to the connecting ring. The magnetic suction plate is used to block the connection between the intermediate cylinder and the detection tube. The intermediate cylinder is made of soft magnetic material.

[0013] A calibration method for detecting hydrogen and methane concentrations in exhaled breath, using the aforementioned device for detecting hydrogen and methane concentrations in exhaled breath, includes the following steps: Step 1: Measure and record the oxygen concentration in the sample gas using an oxygen sensor; Step 2: Calculate the percentage of alveolar gas in the entire sample gas based on the oxygen concentration in the sample gas and the known oxygen concentration in the air. Step 3: Measure the concentration values ​​of hydrogen and methane using the detection sensors, and calculate the corrected hydrogen and methane concentration values ​​by combining them with the alveolar gas percentage. Step 4: Upload the corrected hydrogen and methane concentration values ​​as the final values ​​to the instrument for subsequent processing.

[0014] Compared with the prior art, the present invention has the following advantages: The present invention uses a waste storage cylinder to collect and isolate the first section of gas flowing inside the shell, and uses the second section of gas flowing inside the shell as a sample gas for detection, thereby reducing the influence of the gas guide tube, the air inside the shell, and the gas in the dissected dead space on the concentration of hydrogen and methane in the sample gas, and thus improving the detection accuracy.

[0015] By utilizing the height of the extrusion component to limit the movable range of the waste discharge plate, the maximum volume of the waste gas chamber can be controlled, allowing residual air and anatomical dead space gas to fully enter the waste gas chamber. This reduces the content of anatomical dead space gas in the sample gas while ensuring the volume of the sample gas.

[0016] The sample gas is stored in a transfer tube. After the patient stops exhaling, the sample gas in the transfer tube is released at a constant speed by the gravity of the transfer plate. The concentration of hydrogen and methane is detected by a detection sensor. In this way, the sample gas always passes through the detection sensor at a constant speed when different patients are tested, which improves the accuracy of the test results.

[0017] Air is stored in a backflush tube, and after the test is completed, the air in the backflush tube is released, allowing the air to flow through the connecting tube, transfer chamber, and test tube and "wash" them, reducing the impact of residual sample gas in the connecting tube, transfer chamber, and test tube on subsequent tests. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the waste storage cylinder, transfer cylinder, and backflushing cylinder of the present invention; Figure 3 This is a three-dimensional structural diagram of the air intake pipe, exhaust pressure plate, and threaded knob of the present invention; Figure 4 This is a three-dimensional structural cross-sectional view of the air intake pipe, waste storage cylinder, and connecting pipe of the present invention; Figure 5 This is a three-dimensional structural cross-sectional view of the air intake pipe, exhaust pressure plate, and connecting pipe of the present invention; Figure 6 This is a three-dimensional structural cross-sectional view of the transfer cylinder, transfer pressure plate, and backflush cylinder of the present invention; Figure 7 This is a three-dimensional structural cross-sectional view of the connecting pipe and exhaust pipe of the present invention; Figure 8 This is a three-dimensional structural cross-sectional view of the transfer pressure plate and the back pressure plate in this invention; Figure 9 This is a three-dimensional structural diagram of the connecting ring and magnetic absorbing sheet of the present invention.

[0019] The markings in the diagram are as follows: 1-Shell, 101-Waste Discharge Chamber, 102-Intake Chamber, 2-Intake Pipe, 3-Waste Storage Cylinder, 4-Waste Discharge Pressure Plate, 5-Waste Discharge Sealing Ring, 6-Connecting Pipe, 7-Transfer Cylinder, 8-Detection Pipe, 9-Oxygen Sensor, 10-Detection Sensor, 11-Fixing Ring, 12-Sealing Disc, 13-Fixing Frame, 14-Conversion Plate, 141-Waste Discharge Hole, 15-Mounting Frame, 16-Threaded Knob, 17-Extrusion Part, 18-Transfer Pressure Plate, 181-Pressure Relief Valve, 19-Transfer Sealing Ring, 20-Sealing Part, 21-Backflush Cylinder, 211-Extraction Pipe, 22-Extraction Check Valve, 23-Exhaust Pipe, 24-Exhaust Check Valve, 25-Backflush Pressure Plate, 26-Bellwall, 27-Support Part, 28-Connecting Frame, 29-Z-Shaped Frame, 30-Connecting Ring, 31-Magnetic Adhesive Plate. Detailed Implementation

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] A device for detecting hydrogen and methane concentrations in exhaled breath; please refer to [reference needed]. Figures 1-5 The system includes: a housing 1, which has a waste discharge chamber 101 and an air intake chamber 102. An air intake pipe 2 is fixedly connected to the housing 1. A waste storage cylinder 3 is fixedly connected to the waste discharge chamber 101. The air intake pipe 2 is connected to the lower side of the waste storage cylinder 3. A waste discharge pressure plate 4 is slidably connected to the waste storage cylinder 3. A waste discharge sealing ring 5 is fixedly connected between the waste discharge pressure plate 4 and the waste storage cylinder 3. A connecting pipe 6 is fixedly connected to and connected to the air intake pipe 2. A transfer cylinder 7 is fixedly connected to the air intake chamber 102. Its lower side is connected to the connecting pipe 6. A detection pipe 8 connected to the outside is fixedly connected to and connected to the lower side of the transfer cylinder 7. An oxygen sensor 9 and a detection sensor 10 are installed in the housing 1. The detection pipe 8 is connected to the oxygen sensor 9 and the detection sensor 10 in sequence. A switching component is set in the connecting pipe 6 and is used to control the connection state between the air intake pipe 2 and the connecting pipe 6.

[0022] The above solution aims to address the problem of low detection accuracy in exhaled gas testing due to the influence of air in the air delivery tube and gas analyzer, as well as dead space gas, on the concentration of hydrogen and methane in the sample gas. This solution utilizes a waste collection cylinder 3 to collect and isolate the first section of gas flowing within the housing 1, using the second section as the sample gas for detection. This reduces the impact of air in the air delivery tube and housing 1, as well as dead space gas, on the concentration of hydrogen and methane in the sample gas, thereby improving detection accuracy. The inlet pipe 2 is connected to a disposable filter via the air delivery tube (not shown in the diagram). The waste discharge sealing ring 5 is made of a plastic film (similar to cling film). (and mulch film), initially, the waste discharge sealing ring 5 is in a "stacked" state, and the waste discharge sealing ring 5 is cylindrical in the unfolded state; the waste storage cylinder 3, the waste discharge pressure plate 4, and the waste discharge sealing ring 5 together form the waste gas chamber (the gas entering the waste gas chamber will be referred to as waste gas, which contains residual air and anatomical dead space gas); the detection sensor 10 contains an electrochemical sensor for detecting the concentration of hydrogen and methane. During the process of gas flowing through the detection sensor 10, the detection sensor 10 can detect and record the concentration of hydrogen and methane respectively; the housing 1 is equipped with a touch screen, which allows medical staff to register information of patients to be tested, and also displays the test values.

[0023] Please refer to Figure 4 and Figure 5The switching assembly includes: a fixing ring 11, fixed to the side of the connecting pipe 6 near the intake pipe 2; a fixing frame 13, fixed to the connecting pipe 6, the fixing frame 13 being fixed to a sealing disc 12 in contact with the fixing ring 11 by a tension spring, the fixing frame 13 and the sealing disc 12 being located on opposite sides of the fixing ring 11, and the fixing frame 13 being located on the side of the sealing disc 12 near the intake pipe 2; a conversion plate 14, slidably connected to the waste storage cylinder 3, the waste storage cylinder 3 being provided with a waste discharge hole 141, the conversion plate 14 being used to sequentially seal the waste discharge hole 141 and the connection between the intake pipe 2 and the waste storage cylinder 3, the housing 1 being provided with a first through hole connecting the waste discharge chamber 101 to the outside; the sealing disc 12 being magnetic, and the fixing ring 11 being made of soft magnetic material.

[0024] In the above scheme, the aim is to use the air pressure in the inlet pipe 2 to drive the sealing plate 12 to move, thereby detecting the volume of waste gas in the waste gas chamber. When the volume of waste gas is greater than the volume of residual air and the volume of gas in the dissected dead space, the flow path of the subsequent sample gas is changed. Initially, the conversion plate 14 blocks the waste discharge hole 141, and the sealing plate 12 is magnetically attracted to the left side of the fixing ring 11. At this time, the inlet pipe 2 is only connected to the waste gas chamber. The magnetic attraction between the fixing ring 11 and the sealing plate 12 plays a role in limiting the sealing plate 12. After the volume of the waste gas chamber reaches its maximum, the sealing plate 12 will not move immediately, but will first accumulate pressure in the inlet pipe 2 and the waste gas chamber until the air pressure in the inlet pipe 2 and the waste gas chamber is sufficient to drive the sealing plate 12 to move. Then, the sealing plate 12 can directly drive the conversion plate 14 to move to the left to the limit position, so that the conversion plate 14 blocks the connection between the inlet pipe 2 and the waste storage cylinder 3.

[0025] Please refer to Figures 2-4 It also includes: a mounting bracket 15, which is fixed to the upper side of the waste storage cylinder 3. The mounting bracket 15 is rotatably connected to a threaded knob 16. The threaded knob 16 is threadedly connected to a pressing member 17 that is slidably connected to the mounting bracket 15. The pressing member 17 is used to limit the range of movement of the waste discharge plate 4.

[0026] In the above scheme, the aim is to accommodate the different volumes of anatomical dead space gas in the exhaled air of children and adults. The height of the extrusion member 17 is used to limit the movable range of the exhaust pressure plate 4, thereby controlling the maximum volume of the exhaust chamber. This allows residual air and anatomical dead space gas to fully enter the exhaust chamber, which can both reduce the content of anatomical dead space gas in the sample gas and ensure the volume of the sample gas. Initially, the extrusion member 17 is at its highest point (i.e., the state of the extrusion member 17 in the attached figure). If it is necessary to test children (to reduce the maximum volume of the exhaust chamber), the threaded knob 16 is rotated. The threaded knob 16 moves the extrusion member 17 down through the threaded transmission, so that the highest point that the exhaust pressure plate 4 can move is lowered. This is to accommodate the fact that the volume of anatomical dead space gas in children is smaller than that in adults.

[0027] Please refer to Figures 4-6 and Figure 8It also includes: a transfer pressure plate 18, which is slidably connected inside the transfer cylinder 7, and the transfer pressure plate 18 is fixedly connected to and connected to a pressure relief valve 181. A transfer sealing ring 19 is fixedly connected between the transfer pressure plate 18 and the transfer cylinder 7; a sealing element 20, which is slidably connected inside the transfer cylinder 7 and fixedly connected to the sealing disc 12. The sealing element 20 is used to block the connection between the transfer cylinder 7 and the detection tube 8.

[0028] The above solution aims to address the problem that in existing exhaled gas testing, different patients exhale at different speeds. If the sample gas flow rate entering the gas analyzer is too fast, the sensor cannot respond to the gas being tested in time, resulting in a lower sensor reading than the actual value. If the sample gas flow rate entering the gas analyzer is too slow, the sensor signal will be weak (for example, when using an electrochemical sensor to detect oxygen in exhaled gas, a slow gas flow rate will reduce the number of oxygen molecules participating in the electrode reaction, resulting in a weak current signal), leading to errors in the test results. In this solution, a transfer cylinder 7 is used to store the sample gas. After the patient stops exhaling, the sample gas in the transfer cylinder 7 is released at a uniform speed by the gravity of the transfer pressure plate 18, and the concentration of hydrogen and methane is detected by the detection sensor 10. In this way, the sample gas always passes through the detection sensor 10 at a uniform speed when different patients are tested, improving the accuracy of the test results.

[0029] The transfer cylinder 7, the transfer pressure plate 18, and the transfer sealing ring 19 together form the transfer chamber, which is used to temporarily store the sample gas. The pressure relief valve 181 is used to discharge the excess sample gas after the sample gas volume in the transfer chamber reaches its maximum. In this way, the volume of sample gas in the transfer chamber remains consistent during multiple tests, thereby improving the reliability of the test results. The material of the transfer sealing ring 19 is the same as that of the waste discharge sealing ring 5.

[0030] The working principle of the above scheme is as follows: During exhaled gas testing, medical staff connect a disposable filter and air delivery tube to the inlet tube 2, and adjust the maximum volume of the waste gas chamber by turning the threaded knob 16 according to the patient's age and body size. The patient then takes a deep breath and blows the gas into the air delivery tube through the disposable filter. The anatomical dead space gas entering the air delivery tube first causes the residual air in the air delivery tube and inlet tube 2 to flow and enter the waste gas chamber. The gas volume in the waste gas chamber increases, pushing the exhaust pressure plate 4 upward, further increasing the volume of the waste gas chamber and gradually... As the exhaust sealing ring 5 stretches, the exhaust pressure plate 4 finally contacts the extrusion piece 17, and the volume of the exhaust chamber can no longer increase. At this point, most of the air in the inlet pipe 2 and the duct pipe, as well as the air in the anatomical dead space, enters the exhaust chamber. As the patient continues to blow air, the air pressure in the exhaust chamber and the inlet pipe 2 increases together until the pressure of the air on the sealing plate 12 is sufficient to overcome the magnetic attraction between the sealing plate 12 and the fixing ring 11 and the tension of the adjacent tension spring on the sealing plate 12. Then, the gas in the inlet pipe 2 pushes the sealing plate 12 to the left and stretches the adjacent tension spring of the sealing plate 12.

[0031] During the leftward movement of the sealing disc 12, the sealing disc 12 drives the conversion plate 14 and the sealing element 20 to move together, causing the conversion plate 14 to release the blockage of the waste discharge hole 141 and block the connection between the air inlet pipe 2 and the waste storage cylinder 3, while the sealing element 20 blocks the connection between the transfer cylinder 7 and the detection pipe 8; under the gravity of the waste discharge pressure plate 4, there is a pressure difference between the waste gas in the waste gas chamber and the outside, causing the waste gas stored in the waste gas chamber to be gradually discharged into the waste discharge chamber 101 through the waste discharge hole 141, and then discharged to the outside through the first through hole on the housing 1. Finally, the waste discharge pressure plate 4 and the waste discharge sealing ring 5 are reset; the sample gas in the air inlet pipe 2 passes through the solid The sample gas enters the connecting pipe 6 through the gap between the fixed ring 11 and the sealing plate 12, and then enters the transfer chamber through the connecting pipe 6. This increases the volume of the sample gas in the transfer chamber and pushes the transfer pressure plate 18 upward. The transfer pressure plate 18 pulls the transfer sealing ring 19 to move and unfolds the transfer sealing ring 19 until the transfer pressure plate 18 moves to the highest point of the transfer cylinder 7, at which point the volume of the transfer chamber reaches its maximum. If the patient continues to blow air into the air inlet pipe 2 at this time, the air pressure in the transfer chamber increases and pushes the pressure relief valve 181 to open, expelling the excess sample gas in the transfer chamber into the air inlet chamber 102, and then expelling it to the outside through the second through hole on the housing 1.

[0032] When the volume of the transfer chamber reaches its maximum and the patient stops blowing air into the inlet tube 2, the sample gas in the inlet tube 2 flows in the reverse direction and is discharged to the outside, reducing the air pressure in the inlet tube 2. The sample gas no longer flows through the gap between the fixing ring 11 and the sealing plate 12. At this time, the sealing plate 12 drives the conversion plate 14 and the sealing element 20 to move to the right and reset under the action of the adjacent tension spring, so that the sealing plate 12 contacts the fixing ring 11. The conversion plate 14 re-seals the waste discharge hole 141, and the sealing element 20 releases the blockage at the connection between the transfer cylinder 7 and the detection tube 8. Under the gravity of the transfer pressure plate 18, there is a pressure difference between the air pressure in the transfer chamber and the outside air, so that the sample gas in the transfer chamber enters the detection tube 8 at a uniform speed (due to the pressure difference between the transfer chamber and the outside air). The right end of the trachea 2 is blocked by the fixing ring 11 and the sealing plate 12, so that the sample gas in the transfer chamber can only flow into the detection tube 8. The detection tube 8 guides the gas through the oxygen sensor 9 and the detection sensor 10 in sequence to detect the oxygen, hydrogen and methane content in the gas. After the transfer pressure plate 18 is reset, the sample gas in the detection tube 8 stops flowing. At this time, the oxygen sensor 9 and the detection sensor 10 correct the detected data and display the corrected data on the touch screen of the housing 1. This completes the detection of hydrogen and methane concentrations in the exhaled gas of a single patient. When another patient needs to be tested, the medical staff replaces the disposable filter and repeats the above detection steps.

[0033] Please refer to Figures 6-8 It also includes: a recoil cylinder 21, fixedly connected to the air intake chamber 102, with an air extraction pipe 211 provided on the lower side of the recoil cylinder 21, and an air extraction one-way valve 22 fixedly connected inside the air extraction pipe 211; a second through hole provided on the housing 1 to connect the air intake chamber 102 to the outside; an exhaust pipe 23, fixedly connected to and connected to the lower side of the recoil cylinder 21, and connected to the connecting pipe 6 near the air intake pipe 2; the connection point between the exhaust pipe 23 and the connecting pipe 6 is located on the side of the sealing plate 12 away from the fixed frame 13; an exhaust one-way valve 24 fixedly connected inside the exhaust pipe 23; a recoil pressure plate 25, slidably connected inside the recoil cylinder 21, with a bellows 26 fixedly connected between the recoil pressure plate 25 and the recoil cylinder 21; a trigger assembly, provided on the recoil cylinder 21, used to control the movement sequence of the recoil pressure plate 25 and the transfer pressure plate 18; and a first through hole and a second through hole on the housing 1, respectively located on both sides of the housing 1.

[0034] In the above scheme, the aim is to use the backflush cylinder 21 to store air (referring to the gas in the external environment), and after the test is completed, release the air in the backflush cylinder 21 so that the air flows in the connecting pipe 6, the transfer chamber and the detection pipe 8 and "washes" them, reducing the impact of residual sample gas in the connecting pipe 6, the transfer chamber and the detection pipe 8 on subsequent tests; the backflush cylinder 21, the backflush pressure plate 25 and the bellows 26 together form the backflush chamber for temporarily storing air; the suction check valve 22 is connected from bottom to top, and the exhaust check valve 24 is connected from back to front; the first through hole and the second through hole on the housing 1 are respectively set on the upper and lower sides of the housing 1, which can reduce the content of waste gas in the air in the backflush chamber, so that the content of various substances in the air in the backflush chamber is closer to the content of various substances in the external gas; the exhaust pipe 23 is connected to the right end of the connecting pipe 6.

[0035] Please refer to Figure 8 The triggering components include: a support 27, fixed to the transfer pressure plate 18, for pressing the back pressure plate 25; a connecting frame 28, fixed to the side of the back pressure cylinder 21 near the transfer cylinder 7, the connecting frame 28 is rotatably connected to a Z-shaped frame 29, and a torsion spring is fixed between the two, the Z-shaped frame 29 is used to limit the back pressure plate 25, and the transfer pressure plate 18 is used to press the Z-shaped frame 29.

[0036] In the above scheme, the aim is to control the movement sequence of the transfer pressure plate 18 and the recoil pressure plate 25 by utilizing the swing of the Z-shaped frame 29. Initially, the lower part of the Z-shaped frame 29 is in contact with the transfer pressure plate 18, the adjacent torsion springs of the Z-shaped frame 29 are in a torsional storage state, and the Z-shaped frame 29 always has a tendency to rotate counterclockwise under the action of its adjacent torsion springs (the rotation perspective in this article is from front to back); the connecting frame 28 is provided with limit posts (please refer to the appendix). Figure 8 ), used to limit the maximum angle of counterclockwise rotation of the Z-shaped frame 29.

[0037] Please refer to Figure 6 and Figure 9 It also includes: a connecting ring 30, which is fixed to the transfer sealing ring 19. A magnetic suction piece 31 is fixed to the connecting ring 30. The magnetic suction piece 31 is used to block the connection between the transfer cylinder 7 and the detection tube 8. The transfer cylinder 7 is made of soft magnetic material.

[0038] In the above scheme, the magnetic suction plate 31 is used to block the connection between the connecting pipe 6 and the transfer cylinder 7, and the magnetic suction plate 31 moves up and down during the process of gas passing through the connection between the connecting pipe 6 and the transfer cylinder 7, thereby causing the position of the transfer sealing ring 19 to be repeatedly turned over, so that the sample gas remaining at the position of the transfer sealing ring 19 can be discharged with the air, further reducing the content of the sample gas remaining in the transfer sealing ring 19; the connecting ring 30 is fixed to the middle of the transfer sealing ring 19 after it is unfolded.

[0039] The steps for flushing the residual gas are as follows: As the sample gas in the inlet pipe 2 enters the transfer chamber through the connecting pipe 6, the sample gas pressure in the connecting pipe 6 first increases until the gas pressure in the connecting pipe 6 is sufficient to overcome the magnetic attraction between the magnetic absorbing plate 31 and the transfer cylinder 7. This pushes the magnetic absorbing plate 31 and the connecting ring 30 upward, releasing the blockage of the magnetic absorbing plate 31 at the connection between the connecting pipe 6 and the transfer cylinder 7. Subsequently, the volume of the sample gas in the transfer chamber gradually increases, pushing the transfer pressure plate 18 upward. The transfer pressure plate 18 drives the connecting ring 30 and the magnetic absorbing plate 31 upward through the transfer sealing ring 19.

[0040] During the upward movement of the transfer pressure plate 18, the transfer pressure plate 18 drives the recoil pressure plate 25 to move upward together via the support member 27. The transfer pressure plate 18 loses contact with the lower part of the Z-shaped frame 29, causing the Z-shaped frame 29 to rotate counterclockwise under the action of the adjacent torsion spring and contact the limiting post. As the recoil pressure plate 25 moves upward, it drives the bellows 26 to gradually unfold, increasing the volume of the recoil chamber and generating a pressure difference at the suction pipe 211. As the pressure difference increases, the suction check valve 22 opens, allowing outside air to enter the recoil chamber through the suction pipe 211. As the back pressure plate 25 moves upward, the distance between the back pressure plate 25 and the upper part of the Z-shaped frame 29 gradually decreases until they finally come into contact. The back pressure plate 25 pushes the Z-shaped frame 29 to rotate clockwise and twist its adjacent torsion spring until the intermediate pressure plate 18 moves to the highest point inside the intermediate transfer cylinder 7. At this point, the volume of the back pressure chamber reaches its maximum, the one-way valve 22 closes, and the back pressure plate 25 loses contact with the upper part of the Z-shaped frame 29. At this time, the Z-shaped frame 29 rotates counterclockwise under the action of the adjacent torsion spring, and the upper part of the Z-shaped frame 29 moves to the bottom of the back pressure plate 25, limiting the back pressure plate 25.

[0041] When the Z-shaped frame 29 limits the back pressure plate 25 and the sample gas in the transfer chamber begins to flow into the detection tube 8, the transfer pressure plate 18 drives the support member 27 to move downward. When the transfer pressure plate 18 moves downward and resets, the magnetic suction plate 31 re-contacts the transfer cylinder 7 under the action of magnetic attraction, and seals the connection between the connecting pipe 6 and the transfer cylinder 7. At the same time, the transfer pressure plate 18 contacts the lower part of the Z-shaped frame 29 and squeezes the Z-shaped frame 29 to rotate clockwise, twisting the adjacent torsion spring of the Z-shaped frame 29, causing the upper part of the Z-shaped frame 29 to swing to the right and lose contact with the back pressure plate 25, releasing the limitation on the back pressure plate 25. At this time, the back pressure plate 25 moves downward under its own gravity and squeezes the air in the back pressure chamber to flow into the exhaust pipe 23. The air in the exhaust pipe 23 squeezes the exhaust one-way valve 24 to open and enters the connecting pipe 6. At this time, the air pressure in the connecting pipe 6 gradually increases, pushing the magnetic suction plate 31 upward, releasing the blockage of the connection between the connecting pipe 6 and the transfer cylinder 7 by the magnetic suction plate 31. At this time, some air in the connecting pipe 6 enters the transfer chamber and is discharged to the outside through the detection pipe 8, causing the air pressure in the connecting pipe 6 to decrease. Under the action of gravity and magnetic attraction, the magnetic suction plate 31 re-contacts the transfer cylinder 7, repeating the above steps of increasing the air pressure in the connecting pipe 6, causing the magnetic suction plate 31 to move up and down back and forth. The magnetic suction plate 31 drives the transfer sealing ring 19 to shake through the connecting ring 30, so that the sample gas in the accumulation part of the transfer sealing ring 19 comes into contact with the air flowing in the transfer chamber and is driven out by the air. In this way, the sample gas remaining in the connecting pipe 6, the transfer chamber and the detection pipe 8 is flushed until the back pressure plate 25 is reset and the exhaust one-way valve 24 is closed.

[0042] Please refer to Figures 1-9 A calibration method for detecting hydrogen and methane concentrations in exhaled breath, using the aforementioned device for detecting hydrogen and methane concentrations in exhaled breath, includes the following steps: Step 1: Measure and record the oxygen concentration in the sample gas using oxygen sensor 9; Step 2: Calculate the percentage of alveolar gas in the entire sample gas based on the oxygen concentration in the sample gas and the known oxygen concentration in the air. Step 3: Measure the concentration values ​​of hydrogen and methane using the detection sensor 10, and calculate the corrected concentration values ​​of hydrogen and methane by combining them with the alveolar gas percentage. Step 4: Upload the corrected hydrogen and methane concentration values ​​as the final values ​​to the instrument for subsequent processing.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A device for detecting the concentration of hydrogen and methane in exhaled breath, characterized in that, include: The housing (1) is provided with a waste discharge chamber (101) and an air inlet chamber (102). An air inlet pipe (2) is fixedly connected to the housing (1). A waste storage cylinder (3) is fixedly connected to the waste discharge chamber (101). The air inlet pipe (2) is connected to the lower side of the waste storage cylinder (3). Waste discharge pressure plate (4) is slidably connected inside the waste storage cylinder (3), and a waste discharge sealing ring (5) is fixed between the waste discharge pressure plate (4) and the waste storage cylinder (3). The air inlet pipe (2) is fixedly connected to and connected to a connecting pipe (6). The transfer cylinder (7) is fixedly connected to the air inlet chamber (102), and its lower side is connected to the connecting pipe (6). The lower side of the transfer cylinder (7) is fixedly connected to and connected to the detection pipe (8) which is connected to the outside. The oxygen sensor (9) and the detection sensor (10) are installed in the housing (1). The detection pipe (8) is connected to the oxygen sensor (9) and the detection sensor (10) in sequence. A switching component is installed inside the connecting pipe (6) to control the connection state between the air intake pipe (2) and the connecting pipe (6); The switching component is characterized in that it includes: A retaining ring (11) is fixed to the side of the connecting pipe (6) near the air inlet pipe (2); A fixing bracket (13) is fixed to the connecting pipe (6). The fixing bracket (13) is fixed to a sealing disc (12) that contacts the fixing ring (11) by a tension spring. The fixing bracket (13) and the sealing disc (12) are located on both sides of the fixing ring (11), and the fixing bracket (13) is located on the side of the sealing disc (12) closer to the air inlet pipe (2). The conversion plate (14) is slidably connected to the waste storage cylinder (3). The waste storage cylinder (3) is provided with a waste discharge hole (141). The conversion plate (14) is used to seal the waste discharge hole (141) and the connection between the air inlet pipe (2) and the waste storage cylinder (3) in sequence. The housing (1) is provided with a first through hole that connects the waste discharge chamber (101) to the outside. The sealing disc (12) is magnetic, and the fixing ring (11) is made of soft magnetic material.

2. The device for detecting hydrogen and methane concentrations in exhaled gas according to claim 1, characterized in that, Also includes: Mounting bracket (15) is fixed to the upper side of the waste storage cylinder (3). Mounting bracket (15) is rotatably connected to threaded knob (16). Threaded knob (16) is threadedly connected to pressing member (17) which is slidably connected to mounting bracket (15). Pressing member (17) is used to limit the range of movement of waste discharge plate (4).

3. The device for detecting hydrogen and methane concentrations in exhaled gas according to claim 2, characterized in that, Also includes: The transfer pressure plate (18) is slidably connected inside the transfer cylinder (7). The transfer pressure plate (18) is fixedly connected to and connected to a pressure relief valve (181). A transfer sealing ring (19) is fixedly connected between the transfer pressure plate (18) and the transfer cylinder (7). The sealing element (20) is slidably connected inside the transfer cylinder (7). The sealing element (20) is fixedly connected to the sealing disc (12). The sealing element (20) is used to block the connection between the transfer cylinder (7) and the detection tube (8).

4. The device for detecting hydrogen and methane concentrations in exhaled gas according to claim 3, characterized in that, Also includes: A backflush cylinder (21) is fixedly connected to the air intake chamber (102). An air extraction pipe (211) is provided on the lower side of the backflush cylinder (21). An air extraction one-way valve (22) is fixedly connected inside the air extraction pipe (211). The housing (1) is provided with a second through hole that connects the air intake chamber (102) to the outside. The exhaust pipe (23) is fixedly connected to and connected to the lower side of the backflush cylinder (21), and is connected to the connecting pipe (6) near the intake pipe (2). The connection between the exhaust pipe (23) and the connecting pipe (6) is located on the side of the sealing plate (12) away from the fixed frame (13). An exhaust one-way valve (24) is fixedly connected inside the exhaust pipe (23). A back stamping plate (25) is slidably connected inside the back stamping cylinder (21), and a bellows pipe (26) is fixed between the back stamping plate (25) and the back stamping cylinder (21). A triggering component, disposed on the recoil cylinder (21), is used to control the movement sequence of the recoil pressure plate (25) and the transfer pressure plate (18).

5. The device for detecting hydrogen and methane concentrations in exhaled gas according to claim 4, characterized in that, The first through hole and the second through hole on the housing (1) are located on opposite sides of the housing (1).

6. The device for detecting hydrogen and methane concentrations in exhaled gas according to claim 5, characterized in that, The triggering component includes: Support member (27), fixed to the transfer pressure plate (18), is used to press the back pressure plate (25). The connecting frame (28) is fixed to the side of the recoil cylinder (21) near the transfer cylinder (7). The connecting frame (28) is rotatably connected to the Z-shaped frame (29), and a torsion spring is fixed between the two. The Z-shaped frame (29) is used to limit the recoil pressure plate (25), and the transfer pressure plate (18) is used to squeeze the Z-shaped frame (29).

7. The device for detecting hydrogen and methane concentrations in exhaled gas according to claim 6, characterized in that, Also includes: A connecting ring (30) is fixed to the transfer sealing ring (19). A magnetic suction piece (31) is fixed to the connecting ring (30). The magnetic suction piece (31) is used to block the connection between the transfer cylinder (7) and the detection tube (8). The transfer cylinder (7) is made of soft magnetic material.

8. A calibration method for detecting hydrogen and methane concentrations in exhaled breath, characterized in that, The device for detecting hydrogen and methane concentrations in exhaled gas as described in claim 7 includes the following steps: Step 1: Measure and record the oxygen concentration in the sample gas using an oxygen sensor (9); Step 2: Calculate the percentage of alveolar gas in the entire sample gas based on the oxygen concentration in the sample gas and the known oxygen concentration in the air. Step 3: Use the detection sensor (10) to measure the concentration values ​​of hydrogen and methane, and combine them with the alveolar gas percentage to calculate the corrected concentration values ​​of hydrogen and methane; Step 4: Upload the corrected hydrogen and methane concentration values ​​as the final values ​​to the instrument for subsequent processing.

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