Pulmonary function measuring device and calibration gas generation method

Abstract

To provide a lung function measuring device capable of generating calibration gas used for the calibration of a sensor used for the examination of a lung function.SOLUTION: A lung function measuring device 1 includes: a stretchable first bag 12 connected to a first gas supply part G1 for supplying examination gas used for the examination of a lung function and a second gas supply part G2 for supplying compressed air; a CO sensor 32 and an He sensor 33 for detecting gas concentration in the examination of the lung function; and a control device 40. The control device 40 supplies the examination gas and the compressed gas to the first bag 12, and generates calibration gas used for the calibration of the CO sensor 32 and the He sensor 33.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a pulmonary function measuring device and a calibration gas generating method. [Background technology]

[0002] Patent Document 1 discloses, as an example of a pulmonary function measuring device, a pulmonary function testing device capable of testing the diffusing capacity of the lung carbon monoxide (DLco) and the functional residual capacity (FRC) of the lungs using carbon monoxide.

[0003] In a diffusing capacity (DLco) test, the subject inhales a four-component gas mixture containing carbon monoxide and helium that has been injected into an inspiratory bag, and the subject's exhaled breath is collected in the exhalation bag. The concentrations of carbon monoxide and helium in the subject's exhaled breath are then confirmed using a CO analyzer and a He analyzer.

[0004] Functional residual capacity (FRC) is measured using a spirometer with a closed helium circuit. The spirometer is equipped with a cylinder and a piston that can move relative to the cylinder. The subject's exhaled air is injected into the space enclosed by the cylinder and piston, and the amount of exhaled air is measured based on the amount of movement of the piston. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-037368 Summary of the Invention [Problem to be solved by the invention]

[0006] Sensors such as CO analyzers and He analyzers require periodic calibration. The American Thoracic Society (ATS) requires that sensors in pulmonary function measuring devices be calibrated using calibration gases with identified components. Calibration gases have a different composition from the test gases used in lung tests, which contain the above-mentioned four-component gas mixture, and are prepared separately from the test gases.

[0007] However, the frequency of calibration of sensors is relatively low, and the amount of calibration gas used is relatively small. Furthermore, managing the calibration gas along with the test gas is cumbersome. Furthermore, the composition of the calibration gas must be relatively accurate, and the price of the calibration gas is relatively high.

[0008] An object of the present disclosure is to provide a pulmonary function measuring device that can generate a calibration gas used to calibrate a sensor used in a pulmonary function test. [Means for solving the problem]

[0009] A pulmonary function measuring device according to one embodiment of the present disclosure is connected to a first gas supply unit that supplies a first gas, which is one of compressed air and test gases used in pulmonary function testing, and a second gas supply unit that supplies a second gas, which is the other of compressed air and test gases used in pulmonary function testing, and includes an expandable bag, a first sensor that detects the concentration of gas in the pulmonary function testing, and a control device, wherein the control device supplies the first gas and the second gas to the bag and generates a calibration gas used to calibrate the first sensor.

[0010] This allows the pulmonary function measuring device to generate the calibration gas using the test gas and compressed air used in the pulmonary function test.

[0011] Furthermore, a pulmonary function measuring device according to one aspect of the present disclosure further includes a first connecting tube connecting the first gas supply unit and the bag, and a second connecting tube connecting a branch portion of the first connecting tube between the first gas supply unit and the bag and the second gas supply unit, wherein the control device supplies the first gas and the second gas to the bag in the following order: first gas, second gas, second gas, and first gas, thereby generating the calibration gas.

[0012] The portion of the first connecting pipe between the branch and the bag is a shared portion through which both the test gas and compressed air flow. Therefore, for example, after the test gas is supplied to the bag, the test gas remains in the shared portion, and when compressed air is next supplied, the test gas in the shared portion is first injected into the bag. In this case, the amount of compressed air injected into the bag is reduced by an amount corresponding to the volume of the gas flow path in the shared portion.

[0013] Therefore, the control device supplies the test gas and compressed air to the bag in the following order: test gas, compressed air, compressed air, test gas. The test gas remaining in the shared area after the test gas has been supplied is injected into the bag when compressed air is supplied after the test gas. Also, the compressed air remaining in the shared area after compressed air has been supplied is injected into the bag when test gas is supplied after the compressed air. This makes it possible to equalize the amount of test gas and the amount of compressed air injected into the bag from the shared area. This improves the accuracy of the ratio of test gas to compressed air in the calibration gas. In other words, the pulmonary function testing device can generate calibration gas with high accuracy.

[0014] Furthermore, the pulmonary function measuring device according to one aspect of the present disclosure further includes a pump that aspirates the gas in the bag, and the control device injects the first gas into the bag and then aspirates the gas in the bag before starting to generate the calibration gas.

[0015] This allows the gas in the bag to be discharged before the generation of the calibration gas starts, thereby enabling the pulmonary function measuring device to generate the calibration gas with high accuracy.

[0016] In addition, a pulmonary function measuring device according to one embodiment of the present disclosure further includes a first container having a first space for accommodating the bag, a second container including a cylinder, a piston arranged movably relative to the cylinder, and a flexible diaphragm arranged between the cylinder and the piston, a second sensor detecting the amount of movement of the piston relative to the cylinder, and a third connecting tube connecting the second space surrounded by the cylinder and the piston to the first space.

[0017] When the test gas and compressed air are injected into the bag, gas in the first space, having a volume equal to the volume of the bag expanded, moves to the second space, causing the piston to move. In other words, the amount of movement of the piston corresponds to the amount of test gas and compressed air injected into the bag. Therefore, the control device can detect the volume of gas supplied into the bag based on the detection result of the second sensor. Therefore, the pulmonary function measuring device can accurately generate calibration gas based on the detection result of the second sensor.

[0018] In addition, in the pulmonary function measuring device according to one aspect of the present disclosure, the control device starts supplying the first gas and the second gas to the bag when the piston is located at a predetermined position.

[0019] This allows the control device to accurately detect the volume of gas supplied into the bag based on the amount of movement of the piston, even if the relationship between the volume of gas injected into the second space and the amount of movement of the piston is not proportional.

[0020] In the pulmonary function measuring device according to one aspect of the present disclosure, the volume ratio of the first gas to the second gas supplied to the bag is 1:1.

[0021] This allows the pulmonary function measuring device to easily generate the calibration gas.

[0022] In addition, in the pulmonary function measuring device according to one aspect of the present disclosure, the calibration gas contains carbon monoxide and helium, and in the calibration gas, the proportion of the carbon monoxide is 0.15% by volume and the proportion of the helium is 5% by volume.

[0023] This allows the calibration gas to comply with the regulations of the American Thoracic Society.

[0024] A calibration gas generation method according to one aspect of the present disclosure is applied to a pulmonary function measuring device including: an expandable bag connected via a first connecting tube to a first gas supply unit that supplies a first gas, which is one of compressed air and test gases used in pulmonary function testing; and a second gas supply unit that supplies a second gas, which is the other of the test gases used in pulmonary function testing, via a second connecting tube that connects to a branch of the first connecting tube; and a first sensor that detects the concentration of a gas in the pulmonary function test. The calibration gas generation method generates a calibration gas to be used to calibrate the first sensor, and includes: a first step of supplying the first gas from the first gas supply unit to the bag; a second step of supplying the second gas from the second gas supply unit to the bag after the first step; a third step of supplying the second gas from the second gas supply unit to the bag after the second step; and a fourth step of supplying the first gas from the first gas supply unit to the bag after the third step.

[0025] According to this, the calibration gas generating method can generate the calibration gas with high accuracy as described above. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a diagram showing the configuration of a pulmonary function measuring device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram showing the relationship between the position of the piston and the volume of the second space. [Figure 3A] FIG. 3A is a flow chart showing the steps executed by the control device when generating the calibration gas. [Figure 3B]FIG. 3B is a flowchart that continues from the flowchart shown in FIG. 3A. [Figure 4] FIG. 4 is a diagram showing the amounts of test gas and compressed air in the first bag. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited thereto. The components of each embodiment described below can be combined as appropriate. In addition, some components may not be used.

[0028] FIG. 1 is a diagram showing the configuration of a pulmonary function measuring device 1 according to an embodiment of the present disclosure. The pulmonary function measuring device 1 is a device for measuring the pulmonary function of a subject. The pulmonary function measuring device 1 can perform tests on the pulmonary diffusion capacity (DLCO: hereinafter referred to as the DLCO test) using carbon monoxide and the functional residual capacity (FRC: hereinafter referred to as the FRC test). The FRC test uses the helium closed circuit method. The pulmonary function measuring device 1 includes a first testing unit 10, a second testing unit 20, a measuring unit 30, and a control device 40.

[0029] The first testing unit 10 is used for DLco testing and includes a first container 11, a first bag 12 (corresponding to "bag"), and a second bag 13.

[0030] The first container 11 has a first space R1 therein that houses the first bag 12 and the second bag 13. The first bag 12 and the second bag 13 are expandable. That is, the first bag 12 and the second bag 13 expand when gas is injected into them and contract when the gas is discharged.

[0031] The first bag 12 is filled with a test gas, which is the gas inhaled by the subject. The test gas used in the DLco test is a four-component gas mixture. The four-component gas mixture contains carbon monoxide (CO), oxygen (O2), helium (He), and nitrogen (N2). In the four-component gas mixture, the carbon monoxide content is 0.3% by volume, the helium content is 10% by volume, and the oxygen content is 21% by volume. In the four-component gas mixture, the gas other than carbon monoxide, helium, and oxygen is nitrogen.

[0032] The pulmonary function measuring device 1 includes a first connecting pipe PL1 and a second connecting pipe PL2. The first connecting pipe PL1 is a pipe that connects the first bag 12 and a first gas supply unit G1. The first gas supply unit G1 supplies a four-component mixed gas that is the test gas. The first gas supply unit G1 is, for example, a cylinder.

[0033] A first valve V1 is disposed in the first connecting pipe PL1. The first valve V1 is a solenoid valve that opens and closes the first connecting pipe PL1. When the first valve V1 is closed, the first gas supply unit G1 stops supplying the test gas. On the other hand, when the first valve V1 is open, the first gas supply unit G1 supplies the test gas to the first bag 12 via the first connecting pipe PL1.

[0034] The first connecting pipe PL1 also has a first branching portion D1 (corresponding to a "branching portion") between the first valve V1 and the first bag 12. A second gas supplying portion G2 is connected to the first branching portion D1 via a second connecting pipe PL2. The second gas supplying portion G2 supplies compressed air. The second gas supplying portion G2 is, for example, a cylinder.

[0035] A second valve V2 is disposed in the second connecting pipe PL2. The second valve V2 is a solenoid valve that opens and closes the second connecting pipe PL2. When the second valve V2 is closed, the second gas supply unit G2 stops supplying compressed air. On the other hand, when the second valve V2 is open, the second gas supply unit G2 supplies compressed air to the first bag 12 via the second connecting pipe PL2 and a portion of the first connecting pipe PL1 between the first branch D1 and the first bag 12.

[0036] Both the test gas and compressed air flow through the portion of the first connecting pipe PL1 between the first branch portion D1 and the first bag 12. Hereinafter, the portion of the first connecting pipe PL1 between the first branch portion D1 and the first bag 12 will be referred to as the shared portion Ps.

[0037] The second bag 13 is injected with the breath of the subject who has inhaled the test gas via a pipe not shown.

[0038] The second inspection unit 20 is used for FRC inspection. The second inspection unit 20 includes a second container 21 and a displacement sensor 22 (corresponding to a "second sensor"). The second container 21 includes a cylinder 21a, a piston 21b, and a diaphragm 21c.

[0039] The cylinder 21a is cylindrical and has an opening M at one end. The piston 21b is arranged movably relative to the cylinder 21a. Specifically, the piston 21b moves along the central axis of the cylinder 21a.

[0040] Piston 21b integrally includes disk portion 21b1 and shaft member 21b2. Disk portion 21b1 is located inside cylinder 21a. Shaft member 21b2 is disposed to extend toward the outside of cylinder 21a along the central axis of cylinder 21a. Second container 21 has second space R2 surrounded by cylinder 21a and disk portion 21b1 of piston 21b.

[0041] Diaphragm 21c is disposed between piston 21b and cylinder 21a and is flexible. Diaphragm 21c is annular. The inner peripheral edge of diaphragm 21c is connected to the outer peripheral edge of disc portion 21b1. The outer peripheral edge of diaphragm 21c is connected to the inner periphery of cylinder 21a. Diaphragm 21c is elastic. Diaphragm 21c prevents gas from leaking out of second space R2.

[0042] FIG. 2 is a diagram showing the relationship between the position of piston 21b and the volume of second space R2. The horizontal axis of FIG. 2 represents the position of piston 21b. The vertical axis of FIG. 2 represents the volume of second space R2. The arrow on the horizontal axis indicates the direction in which piston 21b faces opening M of cylinder 21a. When the position of piston 21b is 0 (zero), piston 21b contacts the bottom surface of cylinder 21a.

[0043] As the piston 21b moves toward the opening M of the cylinder 21a, the rate of increase in the volume of the second space R2 decreases slightly. This is due to the shape and elasticity of the diaphragm 21c. The dashed line in Fig. 2 indicates a case where the position of the piston 21b and the volume of the second space R2 are proportional to each other.

[0044] 1 detects the amount of movement of piston 21b relative to cylinder 21a. Displacement sensor 22 is a linear potentiometer including a variable resistor. That is, the electrical resistance value of the variable resistor changes depending on the amount of movement of piston 21b. The detection result of displacement sensor 22 is output to control device 40. Note that displacement sensor 22 may also be a linear encoder.

[0045] In the FRC test, helium inhaled by the subject is supplied to the second space R2. The subject's exhaled breath is also injected into the second space R2. The subject's exhaled breath moves the piston 21b toward the opening M of the cylinder 21a. The amount of exhaled breath of the subject can be detected by the control device 40 based on the detection result of the displacement sensor 22. Specifically, the control device 40 calculates the amount of exhaled breath of the subject by multiplying the detection result of the displacement sensor 22 (the amount of movement of the piston 21b) by the cross-sectional area of ​​the cylinder 21a.

[0046] The pulmonary function measuring device 1 further includes a third connecting pipe PL3. The third connecting pipe PL3 connects the first space R1 of the first container 11 and the second space R2 of the second container 21. Therefore, when gas is injected into the first bag 12 and the first bag 12 expands, gas equivalent to the volume of the expanded first bag 12 flows into the second space R2. The gas flowing into the second space R2 moves the piston 21b toward the opening M of the cylinder 21a, and the amount of gas is detected by the displacement sensor 22. In other words, the control device 40 detects the volume of gas injected into the first bag 12 by multiplying the detection result of the displacement sensor 22 (the amount of movement of the piston 21b) by the cross-sectional area of ​​the cylinder 21a.

[0047] The second inspection section 20 further includes a fourth connecting pipe PL4, a third valve V3, a first pump 23, and a second pump 24.

[0048] A first end of the fourth connecting pipe PL4 is connected to the second space R2 of the second container 21, and a second end of the fourth connecting pipe PL4 is open to the atmosphere. The third valve V3 is disposed on the fourth connecting pipe PL4 and is a solenoid valve that opens and closes the fourth connecting pipe PL4. When the third valve V3 is open, the second space R2 is open to the atmosphere. The first pump 23 and the second pump 24 are disposed on the fourth connecting pipe PL4.

[0049] When the third valve V3 is open, the first pump 23 is driven, and gas in the second space R2 is discharged to the outside via the fourth connecting pipe PL4. When the third valve V3 is open, the second pump 24 is driven, and outside air is drawn into the second space R2 via the fourth connecting pipe PL4. The control device 40 opens the third valve V3 and controls the first pump 23 and the second pump 24 to increase or decrease the volume of gas in the second space R2, thereby moving the piston 21b.

[0050] The measurement unit 30 measures the test items in the DLco test and the FRC test. The measurement unit 30 includes a fifth connecting pipe PL5, a fourth valve V4, a three-way valve Vt, a sixth connecting pipe PL6, a fifth valve V5, a third pump 31 (corresponding to the "pump"), a CO sensor 32 (corresponding to the "first sensor"), and a He sensor 33 (corresponding to the "first sensor").

[0051] The fifth connecting pipe PL5 is arranged with its first and second ends connected to the second space R2. The fourth valve V4 is an electromagnetic valve arranged on the fifth connecting pipe PL5 and opens and closes the fifth connecting pipe PL5.

[0052] The three-way valve Vt is a solenoid valve located between the fourth valve V4 and the second end of the fifth connecting pipe PL5. The three-way valve Vt has a first communication state in which the first end of the fifth connecting pipe PL5 communicates with the second end, and a second communication state in which the first end of the fifth connecting pipe PL5 communicates with the atmosphere.

[0053] The sixth connecting pipe PL6 connects the second branch portion D2, which is located between the fourth valve V4 and the three-way valve Vt in the fifth connecting pipe PL5, to the second bag 13. The fifth valve V5 is an electromagnetic valve that is disposed in the sixth connecting pipe PL6 and opens and closes the sixth connecting pipe PL6.

[0054] The third pump 31, CO sensor 32, and He sensor 33 are disposed between the second branch D2 and the three-way valve Vt in the fifth connecting pipe PL5. The CO sensor 32 detects the concentration of carbon monoxide in the pulmonary function test. The He sensor 33 detects the concentration of helium in the pulmonary function test. The detection results of the CO sensor 32 and the He sensor 33 are output to the control device 40.

[0055] During the DLCO test, when the fourth valve V4 is closed, the fifth valve V5 is open, and the three-way valve Vt is in the second communicating state, the third pump 31 is driven to discharge the gas in the second bag 13 to the outside via the sixth connecting pipe PL6 and the fifth connecting pipe PL5. In this case, the CO sensor 32 detects the concentration of carbon monoxide contained in the subject's breath. The He sensor 33 detects the concentration of helium contained in the subject's breath.

[0056] In the FRC test, when the fourth valve V4 is open, the fifth valve V5 is closed, and the three-way valve Vt is in the first communicating state, the third pump 31 is driven to circulate the gas in the second space R2 through the fifth connecting pipe PL5. In this case, the He sensor 33 detects the concentration of helium contained in the breath of the subject.

[0057] The pulmonary function measuring device 1 further includes a seventh connecting pipe PL7, a sixth valve V6, an eighth connecting pipe PL8, and a seventh valve V7.

[0058] The seventh connecting pipe PL7 connects the third branch D3 of the first connecting pipe PL1 and the fourth branch D4 of the fifth connecting pipe PL5. The third branch D3 of the first connecting pipe PL1 is disposed on the first connecting pipe PL1 between the first bag 12 and the first branch D1. The fourth branch D4 of the fifth connecting pipe PL5 is disposed on the fifth connecting pipe PL5 between the fourth valve V4 and the three-way valve Vt, with the third pump 31, the CO sensor 32, and the He sensor 33 positioned between the fourth branch D4 and the three-way valve Vt.

[0059] The sixth valve V6 is disposed on the seventh connecting pipe PL7 and opens and closes the seventh connecting pipe PL7. During the DLco test and the FRC test, the sixth valve V6 is in a closed state.

[0060] When the fourth valve V4 and the fifth valve V5 are closed, the sixth valve V6 is open, and the three-way valve Vt is in the second communicating state, the third pump 31 is driven to discharge the gas in the first bag 12 to the outside via the first connecting pipe PL1, the seventh connecting pipe PL7, and the fifth connecting pipe PL5. In this case, the CO sensor 32 detects the concentration of carbon monoxide contained in the gas in the first bag 12. The He sensor 33 detects the concentration of helium contained in the gas in the first bag 12.

[0061] The arrangement and types of valves of the fifth connecting pipe PL5, fourth valve V4, three-way valve Vt, sixth connecting pipe PL6, fifth valve V5, third pump 31, CO sensor 32, He sensor 33, seventh connecting pipe PL7, sixth valve V6, second branch D2, third branch D3, and fourth branch D4 are not limited to those shown in Fig. 1. Specifically, the arrangement and types of valves of these components may be any as long as the CO sensor 32 and He sensor 33 can detect the concentrations of carbon monoxide and helium contained in the breath of the subject in a DLco test, the He sensor 33 can detect the concentration of helium contained in the breath of the subject in an FRC test, and the gas in first bag 12 is drawn in by driving third pump 31 as described below, allowing the CO sensor 32 and He sensor 33 to detect the concentrations of carbon monoxide and helium contained in the gas in first bag 12.

[0062] A first end of the eighth connecting pipe PL8 is connected to the first bag 12, and a second end of the eighth connecting pipe PL8 is open to the atmosphere. The seventh valve V7 is disposed on the eighth connecting pipe PL8 and is a solenoid valve that opens and closes the eighth connecting pipe PL8. When the seventh valve V7 is open, the inside of the first bag 12 is open to the atmosphere.

[0063] The control device 40 performs overall control of the pulmonary function measuring device 1. The control device 40 outputs control signals that control the opening and closing of the first valve V1, the second valve V2, the third valve V3, the fourth valve V4, the fifth valve V5, the sixth valve V6, and the seventh valve V7. The control device 40 also outputs a control signal that controls the communication state of the three-way valve Vt.

[0064] The control device 40 is a computer, and includes, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), an internal storage unit, an input interface, and an output interface. The CPU, ROM, RAM, and internal storage unit are connected via an internal bus. The ROM stores programs such as BIOS. The internal storage unit is, for example, a HDD (Hard Disk Drive) or flash memory, and stores operating system programs and application programs. The CPU uses the RAM as a work area and executes programs stored in the ROM or internal storage unit to realize various functions.

[0065] The control device 40 generates a calibration gas used to calibrate the CO sensor 32 and the He sensor 33. The composition of the calibration gas is specified by the American Thoracic Society. Specifically, the calibration gas contains carbon monoxide and helium. In the calibration gas, the carbon monoxide content is 0.15% by volume, and the helium content is 5% by volume.

[0066] In addition, the proportion of carbon monoxide in the above four-component mixed gas is 0.3% by volume, and the proportion of helium is 10% by volume. In other words, the calibration gas can be generated by diluting the four-component mixed gas so that the volume ratio of the four-component mixed gas to air is 1:1. Therefore, the control device 40 generates the calibration gas used to calibrate the CO sensor 32 and the He sensor 33 by supplying the test gas, which is the four-component mixed gas, and compressed air to the first bag 12.

[0067] Fig. 3A is a flowchart executed by the control device 40 when generating a calibration gas. Fig. 3B is a flowchart that continues from the flowchart shown in Fig. 3A. When starting to generate a calibration gas, the control device 40 closes the first valve V1, the second valve V2, the third valve V3, the fourth valve V4, the fifth valve V5, the sixth valve V6, and the seventh valve V7, and sets the three-way valve Vt to the second communicating state.

[0068] Steps S1 to S5 in FIG. 3A correspond to the steps of making preparations before generating the calibration gas, and steps S6 to S13 shown in FIG. 3B correspond to the steps of generating the calibration gas.

[0069] In step S1 shown in FIG. 3A, the control device 40 aspirates the gas in the first bag 12. Specifically, the control device 40 opens only the sixth valve V6 and drives the third pump 31 for a first predetermined time. As a result, gas remaining in the first bag 12, for example, after a DLco test, is aspirated by the third pump 31 and discharged to the outside from the three-way valve Vt via the shared portion Ps of the first connecting pipe PL1, the seventh connecting pipe PL7, and the fifth connecting pipe PL5. The first predetermined time is set to a time during which the gas in the first bag 12 is almost completely aspirated.

[0070] In step S1, when the first bag 12 contracts due to the gas being sucked out of the first bag 12, an amount of gas equal to the change in volume of the first bag 12 moves from the second space R2 to the first space R1 via the third connecting pipe PL3. As a result, the volume of the second space R2 changes by the amount of gas movement. The piston 21b moves due to the change in volume of the second space R2. As described above, the position of the piston 21b and the volume of the second space R2 have the relationship shown in FIG. 2. In other words, the amount of gas being sucked out of the first bag 12 can be detected by the control device 40 based on the detection result of the displacement sensor 22.

[0071] Next, in step S2, the control device 40 supplies the test gas to the first bag 12. Specifically, the control device 40 opens only the first valve V1 for a second predetermined time. The second predetermined time is set to the time it takes for the first bag 12 to be inflated by the test gas. Note that the first predetermined time and the second predetermined time may be set to be equal.

[0072] In step S2, when the first bag 12 expands due to the supply of gas from the first bag 12, an amount of gas equal to the change in volume of the first bag 12 moves from the first space R1 to the second space R2 via the third connecting pipe PL3. As a result, the volume of the second space R2 changes by the amount of gas movement. The piston 21b moves due to the change in volume of the second space R2. In other words, the amount of test gas supplied to the first bag 12 can be detected by the control device 40 based on the detection result of the displacement sensor 22.

[0073] Furthermore, in step S3, the control device 40 determines whether or not the gas in the first bag 12 has been suctioned a predetermined number of times. The predetermined number of times is, for example, two times. If the gas in the first bag 12 has not been suctioned the predetermined number of times (NO in step S3), the control device 40 returns the program to step S1. On the other hand, if the gas in the first bag 12 has been suctioned the predetermined number of times (YES in step S3), the control device 40 causes the program to proceed to step S4.

[0074] In step S4, the control device 40 supplies the test gas to the first bag 12 while discharging the gas inside the first bag 12. Specifically, the control device 40 opens only the first valve V1 and the seventh valve V7 for a second predetermined time.

[0075] Next, in step S5, the control device 40 sucks the gas from the first bag 12. Specifically, the control device 40 opens only the sixth valve V6 and drives the third pump 31 for a first predetermined time. As a result, the volume of the gas in the first bag 12 becomes almost zero, and the composition of the small amount of gas remaining in the first bag 12 is almost equal to the composition of the test gas. Furthermore, when step S5 is completed, the test gas remains in the first connecting pipe PL1.

[0076] In this way, the third pump 31 sucks the gas in the first bag 12. Furthermore, before starting to generate the calibration gas, the control device 40 injects the test gas into the first bag 12 and then sucks the gas in the first bag 12.

[0077] Next, in step S6 shown in FIG. 3B, the control device 40 moves the piston 21b to a first predetermined position Po1 (corresponding to a "predetermined position"). The control device 40 opens only the third valve V3 and controls the first pump 23 and the second pump 24 to move the piston 21b. The control device 40 detects the position of the piston 21b based on the detection result of the displacement sensor 22. As shown in FIG. 2, the first predetermined position Po1 of the piston 21b is between the origin O and the maximum position PoM of the position of the piston 21b.

[0078] Furthermore, in step S7 (corresponding to the "first step"), the control device 40 supplies a predetermined amount Q1 of test gas to the first bag 12. Specifically, the control device 40 opens only the first valve V1. When the test gas is supplied to the first bag 12 via the first connecting pipe PL1, the first bag 12 expands. The change in volume of the first bag 12 is equal to the volume of the test gas supplied to the first bag 12.

[0079] Furthermore, when the first bag 12 expands, the gas in the first space R1 moves to the second space R2 via the third connecting pipe PL3, and the piston 21b moves. The control device 40 detects, based on the detection result of the displacement sensor 22, that a predetermined amount Q1 of test gas has been supplied to the first bag 12. Specifically, the amount of change in the volume of the second space R2, which corresponds to the amount of movement of the piston 21b from the first predetermined position Po1 to the second predetermined position Po2 shown in FIG. 2, corresponds to the predetermined amount Q1 of test gas supplied to the first bag 12.

[0080] That is, when the piston 21b is located at the second predetermined position Po2, the control device 40 detects that the predetermined amount Q1 of test gas has been supplied to the first bag 12, and closes the first valve V1.

[0081] Fig. 4 is a diagram showing the amounts of test gas and compressed air in the first bag 12. The horizontal axis of Fig. 4 indicates the steps of the flowchart shown in Fig. 3B. The vertical axis of Fig. 4 indicates the amount (volume) of gas in the first bag 12. The amount of test gas injected into the first bag 12 in step S7 is a predetermined amount Q1.

[0082] At the end of step S7, the test gas remains in the first connecting pipe PL1, that is, in the shared portion Ps of the first connecting pipe PL1, and air remains in the second connecting pipe PL2.

[0083] 3B, the control device 40 moves the piston 21b to the first predetermined position Po1 in the same manner as in step S6 above. Furthermore, in step S9 (corresponding to the "second step"), the control device 40 supplies a predetermined amount Q1 of compressed air to the first bag 12. Specifically, the control device 40 opens only the second valve V2. As a result, the test gas in the shared portion Ps is first injected into the first bag 12, and then air is injected via the second connecting pipe PL2 and the shared portion Ps.

[0084] When the first bag 12 expands, the gas in the first space R1 moves to the second space R2 via the third connecting pipe PL3, and the piston 21b moves. As in step S7 above, the amount of compressed air supplied to the first bag 12 can be detected by the control device 40 based on the detection result of the displacement sensor 22. When the piston 21b is located at the second predetermined position Po2, the control device 40 detects that a predetermined amount Q1 of compressed air has been supplied toward the first bag 12, and closes the second valve V2.

[0085] 4, in step S9, the amount of test gas injected into the first bag 12 is a shared amount Qs corresponding to the volume of the flow path of the shared portion Ps. The amount of air injected into the first bag 12 is a difference amount Qd obtained by subtracting the shared amount Qs from the predetermined amount Q1.

[0086] At the end of step S9, air remains in the shared portion Ps of the first connecting pipe PL1, the test gas remains in the portion of the first connecting pipe PL1 other than the shared portion Ps, and air remains in the second connecting pipe PL2.

[0087] Next, in step S10 shown in FIG. 3B, the control device 40 moves the piston 21b to the first predetermined position Po1, similar to step S6 described above. Furthermore, in step S11 (corresponding to the "third step"), the control device 40 supplies a predetermined amount Q1 of compressed air to the first bag 12. Specifically, the control device 40 opens only the second valve V2. As a result, air in the shared portion Ps first flows into the first bag 12, and then air is injected into the first bag 12 via the second connecting pipe PL2 and the shared portion Ps.

[0088] When the first bag 12 inflates, the gas in the first space R1 moves to the second space R2 via the third connecting pipe PL3, moving the piston 21b. As in step S7 above, the amount of compressed air supplied to the first bag 12 can be detected by the control device 40 based on the detection result of the displacement sensor 22. When the piston 21b is located at the second predetermined position Po2, the control device 40 detects that a predetermined amount Q1 of compressed air has been supplied to the first bag 12, and closes the second valve V2. As shown in FIG. 4, in step S11, the amount of air injected into the first bag 12 is the predetermined amount Q1.

[0089] At the end of step S11, air remains in the shared portion Ps of the first connecting pipe PL1, the test gas remains in portions of the first connecting pipe PL1 other than the shared portion Ps, and air remains in the second connecting pipe PL2.

[0090] 3B, the control device 40 moves the piston 21b to the first predetermined position Po1, similar to step S6. Furthermore, in step S13 (corresponding to the "fourth step"), the control device 40 supplies a predetermined amount Q1 of test gas to the first bag 12. Specifically, the control device 40 opens only the first valve V1. As a result, air in the shared portion Ps is first injected into the first bag 12, and then the test gas is injected via the first connecting pipe PL1.

[0091] When the first bag 12 expands, the gas in the first space R1 moves to the second space R2 via the third connecting pipe PL3, and the piston 21b moves. As in step S7 above, the amount of test gas supplied to the first bag 12 can be detected by the control device 40 based on the detection result of the displacement sensor 22. When the piston 21b is located at the second predetermined position Po2, the control device 40 detects that a predetermined amount Q1 of test gas has been supplied to the first bag 12, and closes the first valve V1.

[0092] 4, in step S13, the amount of air injected into the first bag 12 is a shared amount Qs, and the amount of test gas injected into the first bag 12 is a differential amount Qd.

[0093] At the end of step S13, the amount of test gas and the amount of air in the first bag 12 are equal to the sum of the predetermined amount Q1, the supply amount, and the difference amount Qd. That is, the volume ratio of the test gas to the air in the gas injected into the first bag 12 is 1:1. Therefore, calibration gas is generated in the first bag 12. The amount of calibration gas is the amount necessary to calibrate the CO sensor 32 and the He sensor 33. When step S13 is completed, the control device 40 terminates the program.

[0094] In this way, the control device 40 supplies the test gas and compressed air to the first bag 12 in the following order: test gas, compressed air, compressed air, and test gas, thereby generating the calibration gas. The control device 40 supplies a predetermined amount Q1 of test gas to the first bag 12 twice. The control device 40 also supplies a predetermined amount Q1 of compressed air to the first bag 12 twice. Therefore, the volume ratio of the test gas to the air supplied to the first bag 12 is 1:1. The control device 40 also starts supplying the test gas and compressed air to the bags when the piston 21b is located at the first predetermined position Po1.

[0095] The calibration of the CO sensor 32 and the He sensor 33 is performed, for example, as follows.

[0096] With calibration gas being generated in the first bag 12, the control device 40 opens only the sixth valve V6 and drives the third pump 31. This causes the calibration gas to pass through the shared portion Ps of the first connecting pipe PL1, the seventh connecting pipe PL7, and the fifth connecting pipe PL5 and then be discharged from the three-way valve Vt to the outside. At this time, the CO sensor 32 and the He sensor 33 detect the concentrations of carbon monoxide and helium contained in the calibration gas and output the detection results to the control device 40. The user adjusts, for example, the control device 40 so that the detection results of the CO sensor 32 and the He sensor 33 correspond to true values ​​for the calibration gas.

[0097] As described above, according to this embodiment, the pulmonary function measuring device 1 is connected to a first gas supply unit G1 that supplies a test gas used in a pulmonary function test and a second gas supply unit G2 that supplies compressed air, and includes an expandable first bag 12, a CO sensor 32 and a He sensor 33 that detect gas concentrations in a pulmonary function test, and a control device 40. The control device 40 supplies the test gas and compressed air to the first bag 12 and generates calibration gases used to calibrate the CO sensor 32 and the He sensor 33.

[0098] This allows the pulmonary function measuring device 1 to generate a calibration gas using the test gas and compressed air used in the test. Furthermore, the pulmonary function measuring device 1 generates the calibration gas using a device used in the pulmonary function test. Therefore, the pulmonary function measuring device 1 can easily generate a calibration gas. Furthermore, the user does not need to purchase a calibration gas separately, thereby reducing the cost of calibrating the CO sensor 32 and the He sensor 33. Furthermore, the pulmonary function measuring device 1 can generate only the required amount of calibration gas. Furthermore, long-term storage of the calibration gas is not required.

[0099] The pulmonary function measuring device 1 further includes a first connecting pipe PL1 that connects the first gas supply unit G1 and the first bag 12, and a second connecting pipe PL2 that connects the second gas supply unit G2 to a first branching portion D1 of the first connecting pipe PL1 between the first gas supply unit G1 and the first bag 12. The control device 40 supplies the test gas and compressed air to the first bag 12 in the following order to generate the calibration gas.

[0100] This allows the amounts of test gas and compressed air injected into the first bag 12 from the shared site Ps to be equal, as described above. This improves the accuracy of the ratio of test gas to compressed air in the calibration gas. In other words, the pulmonary function testing apparatus can generate calibration gas with high accuracy.

[0101] The pulmonary function measuring device 1 further includes a third pump 31 that aspirates the gas in the first bag 12. Before starting to generate the calibration gas, the control device 40 injects the test gas into the first bag 12 and then aspirates the gas in the first bag 12.

[0102] This allows the gas in the first bag 12 to be discharged before the generation of the calibration gas starts, thereby enabling the pulmonary function measuring device 1 to generate the calibration gas with high accuracy.

[0103] The pulmonary function measuring device 1 also includes a first container 11 having a first space R1 that accommodates the first bag 12, a second container 21 that includes a cylinder 21a, a piston 21b that is arranged to be movable relative to the cylinder 21a, and a flexible diaphragm 21c that is arranged between the cylinder 21a and the piston 21b, a displacement sensor 22 that detects the amount of movement of the piston 21b relative to the cylinder 21a, and a third connecting pipe PL3 that connects the second space R2 surrounded by the cylinder 21a and the piston 21b to the first space R1.

[0104] As described above, this allows the control device 40 to detect the volume of gas supplied into the first bag 12 based on the detection result of the displacement sensor 22. Therefore, the pulmonary function measuring device 1 can generate the calibration gas with high accuracy based on the detection result of the displacement sensor 22.

[0105] Furthermore, the control device 40 starts supplying the test gas and compressed air to the first bag 12 when the piston 21b is located at the first predetermined position Po1.

[0106] This allows the control device 40 to accurately detect the volume of gas supplied into the first bag 12 based on the amount of movement of the piston 21b, even if the volume of gas injected into the second space R2 is not proportional to the amount of movement of the piston 21b.

[0107] The volume ratio of the test gas and compressed air supplied to the first bag 12 is 1:1.

[0108] This allows the pulmonary function measuring device 1 to easily generate the calibration gas.

[0109] The calibration gas contains carbon monoxide and helium, with the carbon monoxide content being 0.15% by volume and the helium content being 5% by volume.

[0110] This allows the calibration gas to comply with the regulations of the American Thoracic Society.

[0111] A calibration gas generation method is applied to a pulmonary function measuring device 1 including an expandable first bag 12 connected via a first connecting pipe PL1 to a first gas supply unit G1 that supplies a test gas used in pulmonary function testing and connected to a second gas supply unit G2 that supplies compressed air via a second connecting pipe PL2 that connects to a first branch D1 of the first connecting pipe PL1, and a CO sensor 32 and a He sensor 33 that detect gas concentrations in the pulmonary function testing, and generates a calibration gas used to calibrate the CO sensor 32 and the He sensor 33. The calibration gas generation method includes step S7 of supplying the test gas from the first gas supply unit G1 to the first bag 12, step S9 of supplying compressed air from the second gas supply unit G2 to the first bag 12 after step S7, step S11 of supplying compressed air from the second gas supply unit G2 to the first bag 12 after step S9, and step S13 of supplying the test gas from the first gas supply unit G1 to the first bag 12 after step S11.

[0112] According to this, the calibration gas generating method can generate the calibration gas with high accuracy as described above.

[0113] Next, a pulmonary function measuring device 1 according to a modified example of the embodiment of the present disclosure will be described.

[0114] For example, the first connecting pipe PL1 may not include the first branch portion D1, and the second connecting pipe PL2 may be directly connected to the first bag 12. In this case, the control device 40 supplies equal amounts of the test gas and compressed air to the first bag 12 without determining the order in which the test gas and compressed air are supplied.

[0115] Furthermore, the pulmonary function measuring device 1 may include a flow sensor disposed at the shared site Ps to detect the flow rate of gas per unit time. In this case, the control device 40 detects that the test gas and compressed air have each been supplied in predetermined amounts Q1 to the first bag 12, based on the detection result of the flow sensor instead of the detection result of the displacement sensor 22. The flow sensor may be disposed in the third connecting pipe PL3. In this case, a first end of the third connecting pipe PL3 may be connected to the first space R1, and a second end of the third connecting pipe PL3 may be open to the atmosphere.

[0116] Furthermore, the control device 40 does not have to execute steps S6, S8, S10, and S12. In this case, it is desirable that the volume of gas injected into the second space R2 and the amount of movement of the piston 21b are proportional to each other.

[0117] When the control device 40 does not execute steps S6, S8, S10, and S12, if the relationship between the volume of the second space R2 and the position of the piston 21b is not proportional as shown in FIG. 2, the movement amount of the piston 21b relative to the volume change amount of the second space R2 varies depending on the position of the piston 21b at the start of the volume change of the second space R2. Therefore, the control device 40 multiplies the movement amount of the piston 21b by a correction coefficient corresponding to the position of the piston 21b at the start of the volume change of the second space R2. The correction coefficient is derived based on the relationship between the movement amount of the piston 21b relative to the volume change amount of the second space R2 and the position of the piston 21b, and is stored in advance in the internal storage unit of the control device 40. This allows the control device 40 to accurately calculate the supply amounts of compressed air and test gas based on the detection results (movement amount of the piston 21b) of the displacement sensor 22 in steps S7, S9, S11, and S13.

[0118] Furthermore, in step S9, the control device 40 may supply a second predetermined amount of compressed air, which is different from the predetermined amount Q1, toward the first bag 12. In this case, in step S13, the control device 40 supplies the second predetermined amount of test gas toward the first bag 12. In this case, the volume ratio of the test gas to air supplied to the first bag 12 is also 1:1, and the volume ratio of the test gas to air in the gas injected into the first bag 12 is also 1:1.

[0119] The test gas may also be a gas containing carbon monoxide (CO), methane (CH), oxygen (O), and nitrogen (N). In the test gas, the carbon monoxide content is 0.3% by volume, the methane content is 0.3% by volume, and the oxygen content is 21% by volume. In the test gas, the gas other than carbon monoxide, methane, and oxygen is nitrogen. In this case, the measurement unit 30 may further include a sensor for detecting the concentration of methane in the pulmonary function test.

[0120] The test gas may also be a gas containing carbon monoxide (CO), neon (Ne), oxygen (O2), and nitrogen (N2). In the test gas, the carbon monoxide content is 0.3 volume %, the neon content is 0.5 volume %, and the oxygen content is 21 volume %. In the test gas, the gas other than carbon monoxide, neon, and oxygen is nitrogen. In this case, the measurement unit 30 may further include a sensor for detecting the neon concentration in the pulmonary function test.

[0121] Pulmonary function measuring device 1 may also include a sensor for detecting the concentration of another type of gas instead of CO sensor 32 and He sensor 33. In this case, the sensor needs only to be used for pulmonary function testing and capable of detecting the components of the calibration gas. Examples of other types of gas include methane, neon, butane, and argon.

[0122] Alternatively, the first gas supply unit G1 may supply compressed air. In this case, the second gas supply unit G2 supplies the test gas. In addition, the control device 40 supplies compressed air via the first connecting pipe PL1 in steps S2 and S4. In this case, when step S5 is completed, air remains in the shared region Ps, and the composition of the gas remaining in the first bag 12 is approximately equal to the composition of air.

[0123] Furthermore, when the first gas supply unit G1 supplies compressed air, the control device 40 supplies a predetermined amount Q1 of compressed air to the first bag 12 in steps S7 and S13, and supplies a predetermined amount Q1 of test gas to the first bag 12 in steps S9 and S11. As a result, similar to the above embodiment, the amounts of test gas and air in the first bag 12 are equal when step S13 is completed. In other words, the volume ratio of the test gas to air in the gas injected into the first bag 12 is 1:1. In other words, a calibration gas is generated in the first bag 12.

[0124] That is, the pulmonary function measuring device 1 is connected to a first gas supply unit G1 that supplies a first gas, which is one of the test gases used in the pulmonary function test, and a second gas supply unit G2 that supplies a second gas, which is the other of the test gases used in the pulmonary function test, and is equipped with an expandable first bag 12, a CO sensor 32 and a He sensor 33 that detect the concentrations of gases in the pulmonary function test, and a control device 40. The control device 40 supplies the first gas and the second gas to the first bag 12 and generates calibration gases used to calibrate the CO sensor 32 and the He sensor 33.

[0125] The pulmonary function measuring device 1 also includes a first connecting pipe PL1 that connects the first gas supply unit G1 and the first bag 12, and a second connecting pipe PL2 that connects the second gas supply unit G2 to a first branching portion D1 in the first connecting pipe PL1 between the first gas supply unit G1 and the first bag 12. The control device 40 supplies the first gas and the second gas to the first bag 12 in the order of the first gas, second gas, second gas, and first gas to generate the calibration gas.

[0126] Furthermore, before starting the generation of the calibration gas, the control device 40 injects the first gas into the first bag 12 and then sucks the gas from within the first bag 12.

[0127] The calibration gas generation method is applied to a pulmonary function measuring device (1) including an expandable first bag (12) connected via a first connecting pipe (PL1) to a first gas supply unit (G1) that supplies a first gas, which is one of the test gases used in the compressed air and pulmonary function tests, and connected via a second connecting pipe (PL2) that connects to a first branch (D1) of the first connecting pipe (PL1) to a second gas supply unit (G2) that supplies a second gas, which is the other of the test gases used in the compressed air and pulmonary function tests, and a CO sensor (32) and a He sensor (33) that detect gas concentrations in the pulmonary function test, and generates a calibration gas used to calibrate the CO sensor (32) and the He sensor (33). The calibration gas generation method includes step S7 of supplying a first gas from a first gas supply unit G1 to a first bag 12, step S9 of supplying a second gas from a second gas supply unit G2 to the first bag 12 after step S7, step S11 of supplying the second gas from the second gas supply unit G2 to the first bag 12 after step S9, and step S13 of supplying the first gas from the first gas supply unit G1 to the first bag 12 after step S11. [Explanation of symbols]

[0128] 1. Pulmonary function measuring device 11 1st container 12 First Bag (Bag) 13 Second Bag 21 Second container 21a Cylinder 21b piston 21c diaphragm 22 Displacement sensor (second sensor) 31 Third Pump (Pump) 32 CO sensor (first sensor) 33He sensor (first sensor) 40 Control device D1 First branch (branch) G1 First gas supply section G2 Second gas supply unit PL1 First connecting pipe PL2 Second connecting pipe PL3 3rd connecting pipe Po1 1st predetermined position (predetermined position) R1 First space R2 2nd space

Claims

1. an expandable bag connected to a first gas supply unit that supplies a first gas, which is one of compressed air and a test gas used in a pulmonary function test, and a second gas supply unit that supplies a second gas, which is the other of compressed air and a test gas used in a pulmonary function test; a first sensor for detecting a concentration of a gas in the pulmonary function test; a first container having a first space for accommodating the bag; a second container including a cylinder, a piston movably disposed relative to the cylinder, and a flexible diaphragm disposed between the cylinder and the piston; a second sensor that detects the amount of movement of the piston relative to the cylinder; a third connecting pipe connecting a second space surrounded by the cylinder and the piston to the first space; a control device; the control device supplies the first gas and the second gas to the bag to generate a calibration gas used to calibrate the first sensor; Pulmonary function measuring device.

2. a first connecting pipe connecting the first gas supply unit and the bag; a second connecting pipe connecting a branched portion of the first connecting pipe between the first gas supply unit and the bag and the second gas supply unit, the control device supplies the first gas and the second gas to the bag in the order of the first gas, the second gas, the second gas, and the first gas to generate the calibration gas; The pulmonary function measuring device according to claim 1 .

3. Further, a pump is provided to suck gas from the bag. the control device injects the first gas into the bag and then aspirates the gas in the bag before starting to generate the calibration gas; The pulmonary function measuring device according to claim 2 .

4. the control device starts supplying the first gas and the second gas to the bag when the piston is at a predetermined position. The pulmonary function measuring device according to claim 1 .

5. The volume ratio of the first gas to the second gas supplied to the bag is 1:

1. The pulmonary function measuring device according to claim 1 .

6. the calibration gas includes carbon monoxide and helium; In the calibration gas, the proportion of carbon monoxide is 0.15% by volume and the proportion of helium is 5% by volume. The pulmonary function measuring device according to claim 1 .

7. A calibration gas generation method applied to a pulmonary function measuring device having an expandable bag connected via a first connecting tube to a first gas supply unit that supplies a first gas, which is one of the test gases used in air and pulmonary function tests, and connected via a second connecting tube that connects to a branch of the first connecting tube to a second gas supply unit that supplies a second gas, which is the other of the test gases used in air and pulmonary function tests, and a first sensor that detects the concentration of a gas in a pulmonary function test, and generating a calibration gas used to calibrate the first sensor, comprising: a first step of supplying a predetermined amount of the first gas from the first gas supply unit to the bag while the first gas remains in the first connecting pipe, the amount being greater than a shared amount corresponding to a volume of a flow path in a shared portion of the first connecting pipe between the bag and the branching portion; a second step of supplying the predetermined amount of the second gas from the second gas supply unit to the bag in a state in which the first gas remains in the shared portion and the second gas remains in the second connecting pipe after the first step; a third step of supplying the predetermined amount of the second gas from the second gas supply unit to the bag in a state in which the second gas remains in the shared portion and in the second connecting pipe after the second step; a fourth step of supplying the predetermined amount of the first gas from the first gas supply unit to the bag in a state in which the second gas remains in the shared portion and the first gas remains in a portion of the first connecting pipe other than the shared portion after the third step, Calibration gas generation method.

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