Lung function measurement device

Abstract

To detect the volume of exhaled air from a subject used in lung function testing using a lung function measuring device. [Solution] The lung function measuring device 1 comprises a second expandable bag 12 located in a first space R1 into which the exhaled breath of a subject who has inhaled a test gas during a lung function test is injected; a second container 20 including a cylinder 21 and a piston 22 movably positioned relative to the cylinder 21; a movement detection sensor 30 for detecting the amount of movement of the piston 22; a first connecting pipe L1 connecting the second space R2 surrounded by the cylinder 21 and the piston 22 to the first space R1; a second connecting pipe L2 whose first end L2a is connected to the second bag 12; a CO sensor 52 and a He sensor 53 located in the second connecting pipe L2 for detecting the concentration of gases; and a control device 40 for deriving the amount of the subject's exhaled breath to be sent to the CO sensor 52 and the He sensor 53 based on the amount of movement of the piston 22 detected by the movement detection sensor 30.

Description

Technical Field

[0001] The present disclosure relates to a pulmonary function measuring device.

Background Art

[0002] Patent Document 1 discloses a pulmonary function testing device that can perform tests on the diffusing capacity of the lung for carbon monoxide (DLco: Diffusing capacity of the Lung Carbon monoxide) and the functional residual capacity of the lung (FRC: Functional Residual Capacity) as an example of a pulmonary function measuring device.

[0003] In the test for the diffusing capacity of the lung (DLco), a subject inhales a four-component mixed gas containing carbon monoxide and helium injected into the inspiratory bag, the subject's exhaled breath is stored in the expiratory bag, and the concentrations of carbon monoxide and helium contained in the subject's exhaled breath are confirmed by a CO analyzer and a He analyzer.

[0004] [[ID=,20]]Also, in the test for the diffusing capacity of the lung, by controlling the on / off of a valve arranged in a pipe, a certain amount (for example, 750 ml) of the subject's exhaled breath is exhaled into a balloon box first, and the next certain amount (sample amount: for example, 1000 ml) is stored in the expiratory bag. The subject's exhaled breath stored in the expiratory bag is sent to a pipe where a CO analyzer and a He analyzer are arranged. Thus, the subject's exhaled breath stored in the expiratory bag is used for the test of pulmonary function.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, due to variations in the timing of the valve's on / off operation, and the subject's inherently low exhalation volume, the amount of exhaled air collected in the exhalation bag may not be sufficient. The exhaled air collected in the bag is used for lung function testing. If the amount of exhaled air (sample volume) in the bag is insufficient, accurate test results may not be obtained. Therefore, there is a request to confirm the amount of exhaled air used for lung function testing.

[0007] This disclosure aims to provide a pulmonary function measuring device that can detect the amount of exhaled air from a subject used in lung function tests. [Means for solving the problem]

[0008] A lung function measuring device according to one aspect of the present disclosure comprises: a first container having a first space; an expandable bag placed in the first space into which the exhaled breath of a subject who has inhaled a test gas in a lung function test is injected; 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 movement detection sensor for detecting the amount of movement of the piston relative to the cylinder; a first connecting tube connecting the second space surrounded by the cylinder and the piston to the first space; a second connecting tube with its first end connected to the bag; a concentration sensor placed in the second connecting tube for detecting the concentration of gases contained in the subject's exhaled breath in the lung function test; a dispensing device placed in the second connecting tube for dispensing the subject's exhaled breath from the bag to the concentration sensor; and a control device, wherein the control device derives the amount of the subject's exhaled breath to be dispensed to the concentration sensor based on the amount of movement of the piston detected by the movement detection sensor.

[0009] According to this, in a lung function test, when the subject's exhaled breath in the bag is delivered to the concentration sensor via a second connecting tube by the delivery device, the amount of gas in the second space can be changed. The piston moves as a result of this change in the amount of gas in the second space. The control device derives the amount of the subject's exhaled breath delivered to the concentration sensor based on the amount of piston movement detected by the movement detection sensor. The amount of the subject's exhaled breath delivered to the concentration sensor corresponds to the amount of the subject's exhaled breath used in the lung function test. In this way, the lung function measuring device can detect the amount of the subject's exhaled breath used in the lung function test.

[0010] Furthermore, in a lung function measuring device according to one aspect of the present disclosure, the second connecting tube is positioned on the second end side of the concentration sensor and has an atmospheric vent that releases the subject's exhaled breath to the atmosphere when the delivery device delivers the subject's exhaled breath to the concentration sensor.

[0011] According to this, when the subject's exhaled breath in the bag is delivered to the concentration sensor via the second connecting tube by the delivery device, the bag contracts. As a result, the gas in the second space moves to the first space via the first connecting tube, and as the amount of gas in the second space decreases, the piston moves. In other words, the amount of piston movement corresponds to the amount of the subject's exhaled breath delivered to the concentration sensor. The control device can reliably derive the amount of the subject's exhaled breath delivered to the concentration sensor (the amount of the subject's exhaled breath used in lung function tests) based on the amount of piston movement detected by the movement detection sensor.

[0012] Furthermore, a lung function measuring device according to one aspect of the present disclosure further comprises a first valve disposed in the first connecting tube for opening and closing the first connecting tube, the second end of the second connecting tube being connected to the second space, and the control device closing the first connecting tube with the first valve when the exhaled breath of the subject in the bag is delivered to the concentration sensor by the delivery device.

[0013] According to this, when the subject's exhaled breath in the bag is delivered to the concentration sensor via the second connecting tube by the delivery device, the subject's exhaled breath in the bag moves to the second space via the second connecting tube. This increases the amount of gas in the second space, causing the piston to move. In other words, the amount of piston movement corresponds to the amount of subject's exhaled breath delivered to the concentration sensor. The control device can reliably derive the amount of subject's exhaled breath delivered to the concentration sensor (the amount of subject's exhaled breath used in lung function tests) based on the amount of piston movement detected by the movement detection sensor.

[0014] Furthermore, a lung function measuring device according to one aspect of the present disclosure further comprises a third connecting tube connecting a mouthpiece into which the subject's exhaled breath is blown and the bag, and a second valve disposed in the third connecting tube for opening and closing the third connecting tube, wherein the control device controls the timing of the operation of the second valve so that the amount of the subject's exhaled breath injected into the bag is a predetermined amount based on the amount of movement of the piston detected by the amount of movement detection sensor when the subject's exhaled breath is blown into the mouthpiece, closes the third connecting tube with the second valve, sends the subject's exhaled breath in the bag to the concentration sensor by the delivery device, and multiplies the concentration of the gas detected by the concentration sensor by the first correction coefficient of the following formula (1). C1 = (Q1 + Q2) / Q1 ... (1) C1 is the first correction coefficient, Q1 is the predetermined amount, and Q2 is the volume of the portion between the second valve and the bag in the third connecting pipe.

[0015] In lung function tests, gas in the area between the second valve and the bag in the third connecting tube mixes with the subject's exhaled breath in the bag. This can reduce the concentration of the subject's exhaled breath and potentially decrease the accuracy of the test. Therefore, the control device multiplies the gas concentration detected by the concentration sensor by the first correction coefficient of equation (1). This allows the lung function measuring device to improve the accuracy of the test.

[0016] Furthermore, in a lung function measuring device according to one aspect of the present disclosure, when the subject's exhaled breath in the bag is being sent to the concentration sensor by the delivery device, the control device multiplies the concentration of the gas detected by the concentration sensor by a second correction coefficient of the following formula (2) in place of the first correction coefficient, depending on whether the amount of change per unit time of the amount of the subject's exhaled breath sent to the concentration sensor is less than or equal to a predetermined change. C2 = (Q3 + Q2) / Q3 ... (2) C2 is the second correction coefficient, and Q3 is the amount of exhaled breath from the subject sent to the concentration sensor when the change in the amount of exhaled breath from the subject per unit time sent to the concentration sensor becomes less than or equal to a predetermined change.

[0017] The less exhaled breath from the subject in the bag at the start of the test, the larger the ratio of the volume of the area between the second valve in the third connecting tube and the bag to the volume of exhaled breath from the subject in the bag, and the greater the decrease in the concentration of the subject's exhaled breath. In other words, the less exhaled breath from the subject in the bag at the start of the test, the more likely the accuracy of the test will decrease. Also, when the exhaled breath from the subject in the bag is being sent to the concentration sensor, if the amount of exhaled breath in the bag becomes relatively small, the rate of change per unit time of the amount of exhaled breath sent to the concentration sensor decreases. Therefore, the control device multiplies the gas concentration detected by the concentration sensor by the second correction coefficient instead of the first correction coefficient when the rate of change per unit time of the amount of exhaled breath sent to the concentration sensor is less than or equal to a predetermined rate of change. Q3 in equation (2) is the amount of exhaled breath from the subject sent to the concentration sensor when the rate of change per unit time of the amount of exhaled breath sent to the concentration sensor is less than or equal to a predetermined rate of change. This allows the pulmonary function measurement device to improve the accuracy of the test even when the amount of exhaled air from the subject in the bag is less than the predetermined amount.

[0018] Furthermore, in a lung function measuring device according to one aspect of the present disclosure, the device further comprises a third connecting tube connecting a mouthpiece into which the subject's exhaled breath is blown and the bag, and a second valve disposed in the third connecting tube for opening and closing the third connecting tube, wherein the control device controls the timing of operation of the second valve so that the amount of the subject's exhaled breath injected into the bag is a predetermined amount based on the amount of movement of the piston detected by the movement amount detection sensor when the subject's exhaled breath is blown into the mouthpiece, and adjusts the timing of operation of the second valve so that the amount of the subject's exhaled breath injected into the bag increases when the amount of the subject's exhaled breath sent to the concentration sensor is less than the predetermined amount.

[0019] According to this, for example, if the operating timing of the second valve is delayed relative to the output timing of the control signal due to aging of the second valve, the amount of exhaled breath from the subject injected into the bag decreases, and the amount of exhaled breath from the subject sent to the concentration sensor is less than a predetermined amount, the operating timing of the second valve is adjusted so that the amount of exhaled breath from the subject injected into the bag increases. This makes it possible to increase the amount of exhaled breath from the subject sent to the concentration sensor.

[0020] Furthermore, a lung function measuring device according to one aspect of the present disclosure comprises: a first container having a first space; an expandable bag placed in the first space into which the exhaled breath of a subject who has inhaled a test gas in a lung function test is injected; a first connecting tube having a first end connected to the first space and a second end open to the atmosphere; a flow sensor placed in the first connecting tube; a second connecting tube having a first end connected to the bag and a second end open to the atmosphere; a concentration sensor placed in the second connecting tube for detecting the concentration of gases contained in the subject's exhaled breath in the lung function test; a dispensing device placed in the second connecting tube for dispensing the subject's exhaled breath from the bag to the concentration sensor; and a control device, wherein the control device calculates the amount of the subject's exhaled breath to be dispensed to the concentration sensor based on the detection result of the flow sensor.

[0021] According to this, when the exhaled breath of the subject in the bag is sent to the concentration sensor through the second connecting pipe by the sending device during the lung function test, the bag shrinks, and air flows into the first space through the first connecting pipe. The control device calculates the amount of the subject's exhaled breath sent to the concentration sensor based on the detection result of the flow rate sensor. The amount of the subject's exhaled breath sent to the concentration sensor corresponds to the amount of the subject's exhaled breath used in the lung function test. Thus, the lung function measuring device can detect the amount of the subject's exhaled breath used in the lung function test.

Effect of the Invention

[0022] According to the present disclosure, the lung function measuring device can detect the amount of the subject's exhaled breath used in the lung function test.

Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 is a diagram showing the configuration of a lung function measuring device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a block diagram of the lung function measuring device shown in FIG. 1. [Figure 3] FIG. 3 is a diagram showing a flowchart executed by the control device when the DLco test is performed. [Figure 4] FIG. 4 is a diagram showing a spirogram when the DLco test is performed. [Figure 5] FIG. 5 is a flowchart of a sampling process executed by the control device. [Figure 6] FIG. 6 is a flowchart of an analysis process executed by the control device. [Figure 7] FIG. 7 is a diagram showing the amount of the subject's exhaled breath sent to the CO sensor and the He sensor. [Figure 8] FIG. 8 is a diagram showing the dilution rate of carbon monoxide and the dilution rate of helium displayed on the display device. [Figure 9] FIG. 9 is a diagram showing the configuration of a lung function measuring device according to a second embodiment of the present disclosure.

Modes for Carrying Out the Invention

[0024] The embodiments described below will be explained with reference to the drawings, but the 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.

[0025] <First Embodiment> Figure 1 shows the configuration of the pulmonary function measuring device 1 according to the first embodiment of this disclosure. The pulmonary function measuring device 1 is a device for measuring the lung function of a subject. The pulmonary function measuring device 1 of this first embodiment can perform a lung diffusion capacity test using carbon monoxide (hereinafter referred to as the DLco test) and a functional residual capacity test of the lungs (hereinafter referred to as the FRC test).

[0026] The lung function measuring device 1 comprises a first container 10 having a first space R1, a second container 20 having a second space R2, a first connecting tube L1, a second connecting tube L2, a displacement detection sensor 30, and a control device 40.

[0027] The first connecting pipe L1 connects the first space R1 and the second space R2. The first connecting pipe L1 is equipped with a first valve V1, which is a solenoid valve that opens and closes the first connecting pipe L1.

[0028] The first space R1 of the first container 10 contains the first bag 11 and the second bag 12 (corresponding to "bags"). The first bag 11 and the second bag 12 are expandable and contractible. That is, the first bag 11 and the second bag 12 expand when gas is injected and contract when gas is released.

[0029] The first bag 11 is filled with the test gas, which is the gas that the subject inhales. The test gas used in the DLco test is a mixture of four gases. This mixture contains carbon monoxide (CO), oxygen (O2), helium (He), and nitrogen (N2).

[0030] The first bag 11 is supplied with test gas from the supply unit G via the supply pipe Lp. The supply unit G is, for example, a gas cylinder.

[0031] The second bag 12 is filled with the exhaled breath of the subject who inhaled the test gas during the lung function test. The second bag 12 is connected to the mouthpiece MP through the third connecting tube L3, into which the subject's exhaled breath is blown. The third connecting tube L3 is equipped with a second valve V2, which is a solenoid valve that opens and closes the third connecting tube L3.

[0032] The third connecting pipe L3 has a first branch section D1 between the mouthpiece MP and the second valve V2. The first branch section D1 is connected to the first space R1 via the first branch pipe Ld1. The first branch pipe Ld1 contains the third valve V3, which is a solenoid valve that opens and closes the first branch pipe Ld1.

[0033] Furthermore, the third connecting pipe L3 has a second branch section D2 between the mouthpiece MP and the first branch section D1. The second branch section D2 is connected to the first bag 11 via the second branch pipe Ld2. A fourth valve V4, which is a solenoid valve that opens and closes the second branch pipe Ld2, is located in the second branch pipe Ld2.

[0034] Furthermore, a first check valve Vr1 is positioned between the first branch D1 and the second branch D2 in the third connecting pipe L3. The first check valve Vr1 allows gas to flow from the mouthpiece MP to the second bag 12 in the third connecting pipe L3, and prevents gas from flowing in the reverse direction.

[0035] Furthermore, in the second branch pipe Ld2, a second check valve Vr2 is positioned between the second branch section D2 and the fourth valve V4. The second check valve Vr2 allows gas to flow from the first bag 11 to the mouthpiece MP in the second branch pipe Ld2, and prevents gas from flowing in the reverse direction.

[0036] Furthermore, the second branch pipe Ld2 has a third branch section D3 between the fourth valve V4 and the second check valve Vr2. The third branch section D3 is connected to the first space R1 via the third branch pipe Ld3. The third branch pipe Ld3 is equipped with a fifth valve V5, which is a solenoid valve that opens and closes the third branch pipe Ld3.

[0037] The second container 20 comprises a cylinder 21, a piston 22, and a diaphragm 23.

[0038] The piston 22 integrally comprises a disc portion 22a and a shaft member 22b. The disc portion 22a is located inside the cylinder 21. The shaft member 22b is positioned to extend outward from the cylinder 21 along the central axis of the cylinder 21. The space enclosed by the cylinder 21 and the disc portion 22a of the piston 22 corresponds to the second space R2.

[0039] The diaphragm 23 is positioned between the piston 22 and the cylinder 21 and is flexible. The diaphragm 23 is annular. The inner peripheral edge of the diaphragm 23 is connected to the outer peripheral edge of the disc portion 22a. The outer peripheral edge of the diaphragm 23 is connected to the inner circumference of the cylinder 21. The diaphragm 23 is elastic. The diaphragm 23 prevents gas from leaking out of the second space R2.

[0040] The displacement detection sensor 30 detects the amount of movement of the piston 22 relative to the cylinder 21. The displacement detection sensor 30 is a linear potentiometer that includes a variable resistor. In other words, the electrical resistance value of the variable resistor changes according to the amount of movement of the piston 22. The detection result of the displacement detection sensor 30 is output to the control device 40. Note that the displacement detection sensor 30 may also be a linear encoder.

[0041] The second container 20 is used for the FRC test. The helium closed circuit method is used for the FRC test. In the FRC test, helium inhaled by the subject is supplied to the second space R2. The subject's exhaled breath, after inhaling helium, is also injected into the second space R2. The subject's exhaled breath moves the piston 22 toward the opening M side of the cylinder 21. The amount of the subject's exhaled breath can be detected by the control device 40 based on the detection result of the movement amount detection sensor 30. Specifically, the control device 40 calculates the amount of the subject's exhaled breath by multiplying the detection result of the movement amount detection sensor 30 (the amount of movement of the piston 22) by the cross-sectional area of ​​the cylinder 21.

[0042] The first end L2a of the second connecting pipe L2 is connected to the second bag 12. The second end L2b of the second connecting pipe L2 is connected to the second space R2. The second connecting pipe L2 is equipped with a sixth valve V6, a dispenser 51, a CO sensor 52 (corresponding to a "concentration sensor"), a He sensor 53 (corresponding to a "concentration sensor"), and a three-way valve Vt (corresponding to an "atmospheric vent"). The dispenser 51, CO sensor 52, He sensor 53, and three-way valve Vt are arranged in this order from the second bag 12 toward the second space R2.

[0043] The sixth valve, V6, is a solenoid valve that opens and closes the second connecting pipe, L2.

[0044] The dispensing device 51 delivers the subject's exhaled breath from the second bag 12 to the CO sensor 52 and the He sensor 53 (details will be described later). The dispensing device 51 is, for example, a pump and a blower.

[0045] The CO sensor 52 and the He sensor 53 detect the concentration of gases in the subject's exhaled breath during a lung function test. The CO sensor 52 detects the concentration of carbon monoxide during a lung function test. The He sensor 53 detects the concentration of helium during a lung function test.

[0046] The three-way valve Vt is a three-way valve having a first communication state in which the second bag 12 and the second space R2 are connected, and a second communication state in which the second bag 12 is connected to the atmosphere. When the three-way valve Vt is in the first communication state, the second space R2 and the atmosphere are not connected. When the three-way valve Vt is in the second communication state, the second space R2 and the atmosphere are not connected, and the second bag 12 and the second space R2 are not connected.

[0047] Figure 2 is a block diagram of the lung function measurement device 1 shown in Figure 1.

[0048] The control device 40 is a computer and includes, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), internal storage, an input interface, and an output interface. The CPU, ROM, RAM, and internal storage are connected by an internal bus. The ROM stores programs such as the BIOS. The internal storage is, for example, an HDD (Hard Disk Drive) or flash memory and stores operating system programs and application programs. The CPU realizes various functions by executing programs stored in the ROM or internal storage while using the RAM as a work area.

[0049] The control device 40 acquires the detection results of the movement detection sensor 30, the CO sensor 52, and the He sensor 53. The control device 40 controls the discharger 51, the first valve V1, the second valve V2, the third valve V3, the fourth valve V4, the fifth valve V5, and the sixth valve V6. The control device 40 also displays inspection results and other information on the display device 2 (such as a display).

[0050] Furthermore, the lung function measuring device 1 includes a first switch 61 and a second switch 62 that are turned on by the operator. The first switch 61 and the second switch 62 are switches that output an ON signal when turned on (for example, automatic reset type push switches). Note that the first switch 61 and the second switch 62 may be capacitive touch switches, or if the display device 2 includes a touch panel, they may be touch switches formed on the touch panel.

[0051] The first switch 61 is a switch for advancing the DLco inspection process. Details of the second switch 62 will be described later. The ON signals from the first switch 61 and the second switch 62 are transmitted to the control device 40.

[0052] Next, we will explain the operation of the pulmonary function measurement device 1 when a DLco test is performed.

[0053] Figure 3 shows a flowchart of the actions performed by the control device 40 when a DLco test is conducted. Figure 4 shows a spirogram taken when a DLco test is conducted. The horizontal axis in Figure 4 represents time. On the vertical axis of Figure 4, the area above the reference position P0 (corresponding to the resting expiratory position), indicated by zero (0), (the side indicated by the arrow) corresponds to inspiratory volume, and the area below the reference position P0 (the opposite side from the side indicated by the arrow) corresponds to expiratory volume.

[0054] Before the DLco test begins (before time t1: Figure 4), the test gas is stored in the first bag 11, and the second bag 12 is in a contracted state with most of the gas inside being sucked out. Also, the first valve V1, the third valve V3, and the fifth valve V5 are open, and the second valve V2, the fourth valve V4, and the sixth valve V6 are closed. In this case, the mouthpiece MP is connected to the first space R1 via the first check valve Vr1 and the third valve V3, and also via the second check valve Vr2 and the fifth valve V5. Furthermore, the first space R1 is connected to the second space R2 via the first connecting pipe L1. In addition, the three-way valve Vt is in a second communication state, connecting the second bag 12 to the atmosphere.

[0055] Before the DLco test begins (before time t1: Figure 4), the subject breathes at rest with the mouthpiece MP in their mouth. During this time, the subject's breathing is performed using the gas in the first space R1 and the second space R2.

[0056] Furthermore, the piston 22 moves in accordance with the subject's breathing. The amount of movement of the piston 22 corresponds to the amount of air the subject inhales (subject's inspiratory volume) and the amount of air the subject exhales (subject's expiratory volume). The control device 40 can calculate the subject's inhalatory and expiratory volumes in real time by multiplying the detection result of the movement detection sensor 30 (the amount of movement of the piston 22) by the cross-sectional area of ​​the cylinder 21. Based on the detection result of the movement detection sensor 30, the control device 40 generates a spirogram (Figure 4) and displays it on the display device 2 in real time.

[0057] When the DLco test is started, the control device 40 performs the first exhalation process in step S1 shown in Figure 3. The first exhalation process is the process of having the subject exhale to the maximum exhalation position. During the first exhalation process, the control device 40 switches the fifth valve V5 to the closed state and displays a message on the display device 2 indicating that the subject should exhale forcefully.

[0058] In response to the display on the display device 2, the subject exhales forcefully. As a result, the subject's exhaled air flows into the first space R1 via the first check valve Vr1 and the third valve V3, the gas in the first space R1 moves to the second space R2 via the first connecting pipe L1, and the piston 22 moves toward the opening M side of the cylinder 21. At this time, in Figure 4, the inspiratory volume decreases from the moment the subject starts exhaling (time t1), and the expiratory volume increases beyond the reference level P0.

[0059] Next, in step S2 shown in Figure 3, the control device 40 determines whether or not it has acquired the first predetermined signal. The first predetermined signal is the ON signal of the first switch 61. If the control device 40 has not acquired the first predetermined signal (NO in step S2), it repeats step S2.

[0060] When the operator determines that the exhalation volume has reached the maximum exhalation level based on the spirogram (Figure 4) displayed on the display device 2, they turn on the first switch 61. When the control device 40 receives the ON signal from the first switch 61 (YES in step S2), it proceeds to step S3 of the program.

[0061] In step S3, the control device 40 performs the inhalation process. The inhalation process involves having the subject inhale the test gas. During the inhalation process, the control device 40 switches the third valve V3 to the closed state and the fourth valve V4 to the open state, and also displays a message on the display device 2 indicating that the subject should inhale forcefully.

[0062] In response to the display on the display device 2, the subject takes a forceful breath. This causes the subject to inhale the test gas in the first bag 11 via the fourth valve V4 and the second check valve Vr2. At this time, the first bag 11 contracts, the gas in the second space R2 moves to the first space R1 via the first connecting pipe L1, and the piston 22 moves toward the bottom surface B of the cylinder 21. At this time, in Figure 4, the exhalation volume decreases from the moment the subject starts inhaling the test gas (time t2), and the inhalation volume increases beyond the reference level P0.

[0063] Next, in step S4 shown in Figure 3, the control device 40 determines whether or not a first predetermined time has elapsed. The first predetermined time is the time required for the carbon monoxide contained in the test gas to be absorbed into the subject's blood. The first predetermined time is, for example, 10 seconds. If the first predetermined time has not elapsed (NO in step S4), the control device 40 repeats step S4.

[0064] Based on the spirogram displayed on the display device 2 (Figure 4), the operator determines that the inspiratory volume has reached the maximum inspiratory position and instructs the subject to stop breathing. As shown in Figure 4, from the moment the subject stops breathing (time t3), the subject's inspiratory volume is maintained at approximately the maximum inspiratory position. At this time, carbon monoxide (CO) contained in the test gas is absorbed into the subject's blood. On the other hand, helium (He) contained in the test gas is not absorbed into the subject's blood.

[0065] If the first predetermined time has elapsed (YES in step S4), the control device 40 proceeds to step S5 of the program.

[0066] The control device 40 performs a sampling process in step S5. The sampling process involves collecting the exhaled breath of a subject who has inhaled the test gas for use in a lung function test.

[0067] Figure 5 is a flowchart of the sampling process performed by the control device 40. In step S11, the control device 40 performs the second exhalation process. The second exhalation process involves having the subject exhale forcefully and allowing the subject's exhaled air to flow into the first space R1.

[0068] During the second exhalation process, the control device 40 switches the third valve V3 to the open state and displays a message on the display device 2 indicating that the user should exhale forcefully.

[0069] In response to the display on the display device 2, the subject exhales forcefully. As a result, the subject's exhaled breath, which has inhaled the test gas, flows into the first space R1 via the first check valve Vr1 and the third valve V3. The gas in the first space R1 moves to the second space R2 via the first connecting pipe L1, and the piston 22 moves toward the opening M side of the cylinder 21. In other words, the amount of movement of the piston 22 corresponds to the amount of exhaled breath (the amount of air the subject exhales). At this time, in Figure 4, the amount of inhaled air decreases from the moment the subject starts exhaling (time t4).

[0070] Next, in step S12 shown in Figure 5, the control device 40 determines whether the first discharge volume Br1 is equal to or greater than a first predetermined amount. The first discharge volume Br1 is the amount of exhaled air from the time the subject began to exhale (time t4). The control device 40 calculates the first discharge volume Br1 based on the amount of movement of the piston 22 from the time the subject began to exhale (time t4).

[0071] The first predetermined volume is determined based on the values ​​specified by the American Thoracic Society (ATS). For example, the first predetermined volume is 750 ml. The first predetermined volume is pre-stored in the memory unit 41 (Figure 2) of the control device 40.

[0072] Furthermore, the sum of the volume of the mouthpiece MP, the volume between the mouthpiece MP and the first branch section D1 in the third connecting pipe L3, and the volume between the first branch section D1 and the third valve V3 in the first branch pipe Ld1 is smaller than the first predetermined amount. As a result, the gas between the mouthpiece MP and the third valve V3 is discharged into the first space R1.

[0073] If the first discharge volume Br1 is less than the first predetermined amount (NO in step S12), the control device 40 repeats step S12. At this time, the first discharge volume Br1 increases as the subject exhales. If the first discharge volume Br1 is equal to or greater than the first predetermined amount (YES in step S12), the control device 40 advances the program to step S13.

[0074] In step S13, the control device 40 performs the third exhalation process. The third exhalation process is the process of allowing the subject's exhaled breath to flow into the second bag 12 while the subject continues to exhale. In the third exhalation process, the control device 40 switches the third valve V3 to the closed state and the second valve V2 to the open state. As a result, the subject's exhaled breath flows into the second bag 12 via the first check valve Vr1 and the second valve V2, causing the second bag 12 to inflate.

[0075] As the second bag 12 expands, the gas in the first space R1 moves further into the second space R2 via the first connecting pipe L1, and the piston 22 moves further toward the opening M side of the cylinder 21. At this time, in Figure 4, the intake volume decreases further from the point in time when the second valve V2 is switched to the open state (time t5).

[0076] Next, in step S14, the control device 40 determines whether the second discharge volume Br2 is equal to or greater than the second predetermined volume (corresponding to "determined volume"). The second discharge volume Br2 is the amount of exhaled air from the subject from the time the second valve V2 was switched to the open state (time t5). The control device 40 calculates the second discharge volume Br2 based on the amount of movement of the piston 22 from the time the second valve V2 was switched to the open state (time t5).

[0077] The second predetermined volume is determined based on the values ​​set by the American Thoracic Society (ATS). For example, the second predetermined volume is 1000 ml. The second predetermined volume is pre-stored in the memory unit 41.

[0078] If the second discharge volume Br2 is less than the second predetermined amount (NO in step S14), the control device 40 determines in step S15 whether or not the first predetermined signal has been acquired. The operator turns on the first switch 61 when the second discharge volume Br2 is less than the second predetermined amount, for example, when the subject has exhaled completely and the subject's exhalation has stopped.

[0079] If the control device 40 has not acquired the first predetermined signal (NO in step S15), it returns the program to step S14. In this case, the control device 40 repeatedly executes steps S14 and S15. The second discharge volume Br2 increases as the subject exhales.

[0080] If the second discharge amount Br2 becomes equal to or greater than the second predetermined amount while the control device 40 has not acquired the first predetermined signal (YES in step S14), the control device 40 advances the program to step S16. On the other hand, if the control device 40 acquires the first predetermined signal while the second discharge amount Br2 is less than the second predetermined amount (YES in step S15), the control device 40 advances the program to step S16.

[0081] In step S16, the control device 40 performs the fourth exhalation process. In the fourth exhalation process, the control device 40 switches the second valve V2 to the closed state and the third valve V3 to the open state. If the second discharge volume Br2 is greater than or equal to the second predetermined volume (YES in step S14) and the subject continues to exhale, the subject's exhaled breath, which has inhaled the test gas, flows into the first space R1, the gas in the first space R1 moves further into the second space R2 via the first connecting pipe L1, and the piston 22 moves further toward the opening M side of the cylinder 21. In this case, in Figure 4, the inhaled volume decreases further from the time the third valve V3 is switched to the open state (time t6), and the exhaled volume increases beyond the reference position P0.

[0082] On the other hand, if the control device 40 acquires the first predetermined signal when the second discharge volume Br2 is less than the second predetermined volume (YES in step S15), the inspiratory volume increases, for example, when the subject inhales (not shown).

[0083] In this manner, the exhaled breath of the subject who inhaled the test gas is collected in the second bag 12. The exhaled breath in the second bag 12 is used for lung function testing. Hereafter, the amount of exhaled breath injected into the second bag 12 may be referred to as the sample volume.

[0084] As described above, if the second discharge volume Br2 is equal to or greater than the second predetermined volume (YES in step S14), the sample volume is equal to or greater than the second predetermined volume. In this way, the control device 40 controls the operating timing of the second valve V2 so that the amount of exhaled breath from the subject injected into the second bag 12 is equal to the second predetermined volume, based on the amount of movement of the piston 22 detected by the movement volume detection sensor 30. On the other hand, if the control device 40 acquires the first predetermined signal (YES in step S15), the sample volume is less than the second predetermined volume.

[0085] When the control device 40 completes the fourth exhalation processing in step S16, it terminates the sampling process and proceeds to step S6 shown in Figure 3.

[0086] The control device 40 performs the analysis process in step S6. The analysis process involves analyzing the exhaled breath of a subject who has inhaled the test gas. In the analysis process, the dilution ratio, which will be described later, is calculated.

[0087] Figure 6 is a flowchart of the analysis process performed by the control device 40. In step S21, the control device 40 performs the analysis start process.

[0088] Furthermore, during the analysis initiation process, the control device 40 switches the sixth valve V6 to the open state. The control device 40 also drives the delivery device 51 with a predetermined drive amount while the first valve V1 is open, the second valve V2 is closed, the sixth valve V6 is open, and the three-way valve Vt is in the second connected state. As a result, the subject's exhaled breath in the second bag 12 is sent by the delivery device 51 via the second connecting pipe L2 to the CO sensor 52 and the He sensor 53, and released into the atmosphere through the three-way valve Vt. The predetermined drive amount is a fixed drive amount that is set in advance.

[0089] When the subject's exhaled air in the second bag 12 is expelled by the delivery device 51, the second bag 12 contracts. As a result, the gas in the second space R2 moves to the first space R1 via the first connecting pipe L1, and the piston 22 moves toward the bottom surface B of the cylinder 21.

[0090] Furthermore, during the analysis initiation process, the control device 40 starts deriving the amount of exhaled breath from the subject to be sent to the CO sensor 52 and the He sensor 53 based on the amount of movement of the piston 22 detected by the movement detection sensor 30.

[0091] Figure 7 shows the amount of exhaled breath from the subject sent to the CO sensor 52 and the He sensor 53. In Figure 7, the horizontal axis represents time, and the vertical axis represents the volume of the second space R2.

[0092] From the moment the dispensing device 51 starts to operate (time t11), the piston 22 moves toward the bottom surface B of the cylinder 21, causing the volume of the second space R2 to decrease. The amount of change (decrease) in the volume of the second space R2 is calculated based on the amount of movement of the piston 22 detected by the movement detection sensor 30. The amount of change in the volume of the second space R2 from the moment the dispensing device 51 starts to operate (time t11) corresponds to the amount of exhaled breath from the subject sent to the CO sensor 52 and the He sensor 53. In other words, the control device 40 calculates the amount of exhaled breath from the subject sent to the CO sensor 52 and the He sensor 53 based on the amount of movement of the piston 22 detected by the movement detection sensor 30.

[0093] Furthermore, the amount of exhaled breath from the subject sent to the CO sensor 52 and the He sensor 53 is the amount of exhaled breath used for lung function testing, and corresponds to the amount of exhaled breath from the subject who has inhaled the test gas that is analyzed. Hereinafter, the amount of exhaled breath from the subject sent to the CO sensor 52 and the He sensor 53 may be referred to as the analysis amount. As described above, when the discharger 51 is driven by a predetermined drive amount, the volume of the second space R2 decreases at a constant rate. In other words, the analysis amount increases at a constant rate. The control device 40 displays the change in the volume of the second space R2 in real time on the display device 2 in a time chart similar to that in Figure 7.

[0094] The subject's exhaled breath in the second bag 12 is sent to the CO sensor 52 and the He sensor 53 via the second connecting tube L2. The CO sensor 52 detects the concentration of carbon monoxide in the subject's exhaled breath, and the He sensor 53 detects the concentration of helium in the subject's exhaled breath.

[0095] As described above, when the second valve V2 is closed and the subject's exhaled breath in the second bag 12 is being delivered to the CO sensor 52 and He sensor 53 by the delivery device 51, the portion L3a between the second valve V2 and the second bag 12 in the third connecting pipe L3 shown in Figure 1 does not expand or contract and is always in communication with the second bag 12. Therefore, the gas in portion L3a mixes with the subject's exhaled breath in the second bag 12 during the analysis process, diluting the subject's exhaled breath.

[0096] In other words, the gas at site L3a reduces the concentrations of carbon monoxide and helium in the subject's exhaled breath within the second bag 12. In this case, the analysis of the subject's exhaled breath may not be performed accurately.

[0097] Therefore, the control device 40 performs a correction by multiplying the concentration of carbon monoxide detected by the CO sensor 52 and the concentration of helium detected by the He sensor 53 by the first correction coefficient shown in equation (1).

[0098] C1 = (Q1 + Q2) / Q1 ... (1)

[0099] C1 is the first correction factor, Q1 is the second predetermined amount, and Q2 is the volume of the portion L3a between the second valve V2 and the second bag 12 in the third connecting pipe L3.

[0100] The first correction coefficient corrects the concentration of carbon monoxide detected by the CO sensor 52 and the concentration of helium detected by the He sensor 53 so that, when the amount of exhaled breath from the subject in the second bag 12 is the second predetermined amount, the exhaled breath from the subject in the second bag 12 is not diluted by the gas in site L3a.

[0101] Furthermore, during the analysis initiation process, the control device 40 begins calculating the carbon monoxide dilution ratio. The carbon monoxide dilution ratio is the concentration of carbon monoxide detected by the CO sensor 52 relative to the carbon monoxide concentration of the test gas. The carbon monoxide concentration of the test gas is measured in advance and stored in the memory unit 41. The control device 40 calculates the carbon monoxide dilution ratio using the carbon monoxide concentration corrected by the first correction coefficient.

[0102] The control device 40 also starts calculating the helium dilution ratio. The helium dilution ratio is the helium concentration detected by the He sensor 53 relative to the helium concentration of the test gas. The helium concentration of the test gas is measured in advance and stored in the memory unit 41. The control device 40 calculates the helium dilution ratio using the helium concentration corrected by the first correction coefficient.

[0103] When the control device 40 calculates a dilution ratio, it displays the highest dilution ratio among the dilution ratios up to that time on the display device 2. The control device 40 displays the maximum value of the dilution ratio in real time on a time chart.

[0104] Figure 8 shows the dilution ratios of carbon monoxide and helium displayed on the display device 2. In Figure 8, the horizontal axis represents time, and the vertical axis represents the dilution ratio.

[0105] As described above, the carbon monoxide in the test gas is absorbed into the subject's blood, while the helium in the test gas is not absorbed into the subject's blood. Therefore, the dilution ratio of carbon monoxide (CO) is lower than that of helium (He).

[0106] In step S22 shown in Figure 6, the control device 40 determines whether a second predetermined time has elapsed. The second predetermined time is set to be a sufficient time for analyzing the subject's exhaled breath. The second predetermined time is also set to be the time during which, when the amount of the subject's exhaled breath in the second bag 12 is equal to or greater than a second predetermined amount, the discharger 51 is driven at a constant drive amount and not all of the exhaled breath in the second bag 12 is discharged. In other words, when the amount of the subject's exhaled breath in the second bag 12 is equal to or greater than a second predetermined amount and the discharger 51 is driven for the second predetermined time, the amount of analysis (amount of analysis A1: Figure 7) is less than the second predetermined amount. The second predetermined time is, for example, 60 seconds.

[0107] If the second predetermined time has elapsed (YES in step S22), the control device 40 stops the sender 51 in step S23.

[0108] As shown by the solid line in Figure 7, the volume of the second space R2 decreases at a constant rate from the time the dispensing unit 51 starts to operate (time t11) until the second predetermined time has elapsed and the dispensing unit 51 stops operating (time t12). In this case, the amount of analysis (the amount of exhaled breath from the subject sent to the CO sensor 52 and the He sensor 53) corresponds to the amount of analysis A1 which is equal to the change in the volume of the second space R2 from the time the dispensing unit 51 starts to operate (time t11) until the second predetermined time has elapsed and the dispensing unit 51 stops operating (time t12).

[0109] When the control device 40 stops the dispenser 51 in step S23, it terminates the analysis process shown in Figure 6 and ends the program (Figure 3). The operator confirms the DLco test results based on the dilution ratio (Figure 8) displayed on the display device 2.

[0110] On the other hand, if the second predetermined time has not elapsed (NO in step S22), the control device 40 determines in step S24 whether the change in the amount of analyte (the amount of exhaled breath from the subject sent to the CO sensor 52 and the He sensor 53) per unit time is less than or equal to a predetermined change. As described above, as the discharger 51 is driven by a predetermined amount, the volume of the second space R2 decreases at a constant rate. In other words, the amount of exhaled breath from the subject sent to the CO sensor 52 and the He sensor 53 (analyte) increases at a constant rate. That is, the change in the amount of analyte per unit time is approximately constant. The predetermined change is set to a value smaller than this constant value.

[0111] For example, in the sampling process shown in Figure 5, if the first predetermined signal is output in step S15 (YES in step S15), the amount of the subject's exhaled breath injected into the second bag 12 is less than the second predetermined amount, as described above. In this case, the amount of the subject's exhaled breath in the second bag 12 may become extremely small before the second predetermined time has elapsed during the analysis process.

[0112] When the amount of exhaled breath from the subject in the second bag 12 becomes extremely small, as shown by the dashed line in Figure 7, the change in the volume of the second space R2 becomes small from the time when the dispensing device 51 starts to operate (time t11) and before the second predetermined time has elapsed (time t20). In other words, from the time when the dispensing device 51 starts to operate (time t11) and before the second predetermined time has elapsed (time t20), the change in the amount of analysis (the amount of exhaled breath from the subject sent to the CO sensor 52 and the He sensor 53) per unit time becomes less than or equal to a predetermined change.

[0113] In this case, the amount of exhaled breath (analyzed amount) from the subject delivered from the second bag 12 to the CO sensor 52 and the He sensor 53 corresponds to an analytical amount A2 equal to the decrease in volume of the second space R2 from the time the delivery device 51 starts to operate (time t11) until the time when the change in the analytical amount per unit time becomes less than or equal to a predetermined change (time t20). Analyzed amount A2 is less than analytical amount A1.

[0114] Furthermore, if the amount of exhaled breath from the subject in the second bag 12 becomes extremely small before the second predetermined time has elapsed, the subject's exhaled breath will not be sent to the CO sensor 52 and He sensor 53 from the point in time (time t20) when the rate of change of the analyte per unit time falls below the predetermined rate of change, as shown by the dashed line in Figure 8, and the actual dilution ratio will decrease. However, as described above, the control device 40 displays the maximum value of the dilution ratio, so the display device 2 displays the dilution ratio shown by the solid line.

[0115] If the amount of analysis is relatively small, the analysis of the subject's exhaled breath may not be performed properly. Specifically, as the amount of the subject's exhaled breath in the second bag 12 decreases, the ratio of the volume in region L3a shown in Figure 1 to the amount of the subject's exhaled breath in the second bag 12 increases, and the decrease in the concentration of the subject's exhaled breath becomes greater. This may reduce the accuracy of the dilution ratio shown in Figure 8.

[0116] If there is still a volume of the subject's exhaled breath in the second bag 12 and the rate of change of the analyte per unit time is greater than a predetermined rate of change (NO in step S24), the control device 40 returns the program to step S22. In other words, if the second predetermined time has not elapsed and the rate of change of the analyte per unit time is greater than a predetermined rate of change, the control device 40 repeatedly executes steps S22 and S24.

[0117] On the other hand, if the rate of change per unit time of the analyte becomes less than or equal to a predetermined rate of change before the second predetermined time has elapsed (YES in step S24), the control device 40 performs a correction coefficient switching process in step S25. In the correction coefficient switching process, the control device 40 switches from the first correction coefficient described above to the second correction coefficient of the following formula (2). As a result, the control device 40 multiplies the concentration of carbon monoxide detected by the CO sensor 52 and the concentration of helium detected by the He sensor 53 by the second correction coefficient of the following formula (2).

[0118] C2 = (Q3 + Q2) / Q3 ... (3)

[0119] C2 is the second correction coefficient, Q3 is the amount of exhaled breath (analyzed amount) sent to the CO sensor 52 and He sensor 53 when the change in the amount of exhaled breath sent to the CO sensor 52 and He sensor 53 per unit time falls below a predetermined change, and Q2 is the volume of part L3a between the second valve V2 and the second bag 12 in the third connecting tube L3. Q3 in equation (2) corresponds to the analyzed amount A2.

[0120] The carbon monoxide concentration detected by the CO sensor 52 and the helium concentration detected by the He sensor 53 are corrected by the second correction coefficient so that the subject's exhaled breath in the second bag 12 is not diluted by the gas in site L3a. The control device 40 switches to the dilution ratio calculated using the carbon monoxide and helium concentrations corrected by the second correction coefficient and displays it on the display device 2.

[0121] When the control device 40 finishes the correction coefficient switching process in step S25, it stops the dispenser 51 in step S23. Subsequently, the control device 40 terminates the program as described above. In this case, the operator confirms the DLco test results based on the corrected dilution ratio displayed on the display device 2. If the change in the amount of analysis per unit time becomes less than or equal to a predetermined change before the second predetermined time has elapsed (YES in step S24), the analysis process is terminated early by stopping the dispenser 51 before the second predetermined time has elapsed.

[0122] As described above, according to this first embodiment, the pulmonary function measuring device 1 includes a first container 10 having a first space R1, an expandable second bag 12 placed in the first space R1 into which the exhaled breath of a subject who has inhaled a test gas during a pulmonary function test is injected, a second container 20 including a cylinder 21, a piston 22 movably positioned relative to the cylinder 21, and a flexible diaphragm 23 positioned between the cylinder 21 and the piston 22, and a movement that detects the amount of movement of the piston 22 relative to the cylinder 21. The system includes a volume detection sensor 30, a first connecting pipe L1 connecting a second space R2 surrounded by a cylinder 21 and a piston 22 to a first space R1, a second connecting pipe L2 whose first end L2a is connected to a bag, a CO sensor 52 and a He sensor 53 located in the second connecting pipe L2 for detecting the concentration of gases contained in the subject's exhaled breath during a lung function test, a dispensing device 51 located in the second connecting pipe L2 for dispensing the subject's exhaled breath from the second bag 12 to the CO sensor 52 and the He sensor 53, and a control device 40. The control device 40 derives the amount of the subject's exhaled breath to be dispensed to the CO sensor 52 and the He sensor 53 based on the amount of movement of the piston 22 detected by the movement detection sensor 30.

[0123] According to this, in a lung function test, when the subject's exhaled breath in the second bag 12 is delivered to the CO sensor 52 and He sensor 53 via the second connecting tube L2 by the delivery device 51, the amount of gas in the second space R2 can be changed. The piston 22 moves as a result of the change in the amount of gas in the second space R2. The control device 40 derives the amount of the subject's exhaled breath delivered to the CO sensor 52 and He sensor 53 based on the amount of movement of the piston 22 detected by the movement detection sensor 30. The amount of the subject's exhaled breath delivered to the CO sensor 52 and He sensor 53 corresponds to the amount of the subject's exhaled breath (analyzed amount) used in the lung function test. In this way, the lung function measuring device 1 can detect the amount of the subject's exhaled breath used in the lung function test.

[0124] For example, if there is a large variation in the operating timing of the second valve V2 and the third valve V3 during the sampling process due to aging or other factors, and if the amount of exhaled breath from the subject is relatively small, the sample volume may be less than the second predetermined amount. Even in such cases, the analysis volume is calculated during the analysis process, allowing the operator to confirm the amount of exhaled breath from the subject in the second bag 12.

[0125] Furthermore, as described above, the second container 20 is used for the FRC test and is a component that the pulmonary function measurement device 1 already has. In other words, the pulmonary function measurement device 1 can detect the amount of exhaled breath of a subject used for a pulmonary function test using the second container 20 used for the FRC test, without adding any new components.

[0126] Furthermore, the second connecting pipe L2 is located on the second end L2b side of the CO sensor 52 and He sensor 53, and has a three-way valve Vt that releases the subject's exhaled breath into the atmosphere when the discharger 51 delivers the subject's exhaled breath to the CO sensor 52 and He sensor 53.

[0127] According to this, when the exhaled breath of the subject in the second bag 12 is delivered to the CO sensor 52 and He sensor 53 via the second connecting tube L2 by the delivery device 51, the second bag 12 contracts. As a result, the gas in the second space R2 moves to the first space R1 via the first connecting tube L1, and as the amount of gas in the second space R2 decreases, the piston 22 moves. In other words, the amount of movement of the piston 22 corresponds to the amount of exhaled breath of the subject delivered to the CO sensor 52 and He sensor 53. The control device 40 can reliably derive the amount of exhaled breath of the subject delivered to the CO sensor 52 and He sensor 53 (the amount of exhaled breath of the subject used in lung function testing (analyzed amount)) based on the amount of movement of the piston 22 detected by the movement detection sensor 30.

[0128] The pulmonary function measuring device 1 further includes a third connecting tube L3 that connects the mouthpiece MP into which the subject's exhaled breath is blown to the second bag 12, and a second valve V2 located on the third connecting tube L3 that opens and closes the third connecting tube L3. When the subject's exhaled breath is blown into the mouthpiece MP, the control device 40 controls the timing of operation of the second valve V2 based on the amount of movement of the piston 22 detected by the movement detection sensor 30 so that the amount of the subject's exhaled breath injected into the second bag 12 becomes a second predetermined amount, and closes the third connecting tube L3 with the second valve V2, sending the subject's exhaled breath in the second bag 12 to the CO sensor 52 and the He sensor 53 by the delivery device 51. The control device 40 multiplies the gas concentration detected by the CO sensor 52 and the He sensor 53 by the first correction coefficient of formula (1).

[0129] In lung function tests, the gas in the area L3a between the second valve V2 and the bag in the third connecting tube L3 mixes with the subject's exhaled breath in the second bag 12. This can reduce the concentration of the subject's exhaled breath and potentially decrease the accuracy of the test. Therefore, the control device 40 multiplies the gas concentration detected by the CO sensor 52 and the He sensor 53 by the first correction coefficient of equation (1). This allows the lung function measuring device 1 to improve the accuracy of the test.

[0130] Furthermore, when the subject's exhaled breath in the second bag 12 is being delivered to the CO sensor 52 and the He sensor 53 by the delivery device 51, the control device 40 multiplies the concentration of the gas detected by the CO sensor 52 and the He sensor 53 by the second correction coefficient of equation (2), in lieu of the first correction coefficient, depending on whether the amount of change per unit time of the subject's exhaled breath delivered to the CO sensor 52 and the He sensor 53 is less than or equal to a predetermined change.

[0131] The less exhaled breath from the subject in the second bag 12 when the test is started, the larger the ratio of the volume of the portion L3a between the second valve V2 and the second bag 12 in the third connecting tube L3 to the amount of exhaled breath from the subject in the second bag 12, and the greater the decrease in the concentration of the subject's exhaled breath. In other words, the less exhaled breath from the subject in the second bag 12 when the test is started, the more likely the accuracy of the test will decrease. Also, when the exhaled breath from the subject in the second bag 12 is being sent to the CO sensor 52 and the He sensor 53, if the amount of exhaled breath from the subject in the second bag 12 is relatively small, the rate of change per unit time of the amount of exhaled breath sent to the CO sensor 52 and the He sensor 53 decreases. Therefore, the control device 40 multiplies the concentration of the gas detected by the CO sensor 52 and the He sensor 53 by a second correction coefficient instead of a first correction coefficient when the rate of change per unit time of the amount of exhaled breath sent to the CO sensor 52 and the He sensor 53 is less than or equal to a predetermined change. Q3 in equation (2) is the amount of exhaled breath from the subject sent to the CO sensor 52 and the He sensor 53 when the change in the amount of exhaled breath from the subject sent to the CO sensor 52 and the He sensor 53 per unit time falls below a predetermined change. This allows the pulmonary function measurement device 1 to improve the accuracy of the test even when the amount of exhaled breath from the subject in the second bag 12 is less than a predetermined amount.

[0132] Next, a modified example of the first embodiment of this disclosure, a lung function measuring device 1, will be described.

[0133] For example, the lung function measuring device 1 does not need to be equipped with the first valve V1.

[0134] Furthermore, the lung function measuring device 1 does not need to be equipped with a three-way valve Vt. In this case, the second end L2b of the second connecting pipe L2 is not connected to the second space R2 and is open to the atmosphere. In other words, in this case, the second end L2b of the second connecting pipe L2 corresponds to the "atmospheric opening part".

[0135] Furthermore, in the analysis start process (step S21) shown in Figure 6, the pulmonary function measuring device 1 may close the first valve V1 and open the three-way valve Vt to the first connected state. In this case, the subject's exhaled breath in the second bag 12 delivered by the delivery device 51 moves to the second space R2 via the second connecting tube L2, and the piston 22 moves toward the opening M side of the cylinder 21. Then, similar to the first embodiment described above, in the analysis start process, the control device 40 starts deriving the amount of the subject's exhaled breath to be delivered to the CO sensor 52 and the He sensor 53 based on the amount of movement of the piston 22 detected by the movement amount detection sensor 30. In this case, the pulmonary function measuring device 1 does not need to be equipped with the three-way valve Vt.

[0136] The pulmonary function measuring device 1 of this modified example further includes a first valve V1 located on the first connecting tube L1, which opens and closes the first connecting tube L1. The second end L2b of the second connecting tube L2 is connected to the second space R2. When the subject's exhaled air in the second bag 12 is delivered to the CO sensor 52 and He sensor 53 by the delivery device 51, the control device 40 closes the first connecting tube L1 with the first valve V1.

[0137] According to this, when the subject's exhaled breath in the second bag 12 is delivered to the CO sensor 52 and He sensor 53 via the second connecting tube L2 by the delivery device 51, the subject's exhaled breath in the second bag 12 moves to the second space R2 via the second connecting tube L2. This increases the amount of gas in the second space R2, causing the piston 22 to move. In other words, the amount of movement of the piston 22 corresponds to the amount of the subject's exhaled breath delivered to the CO sensor 52 and He sensor 53. Therefore, the control device 40 can reliably derive the amount of the subject's exhaled breath (analyzed amount) delivered to the concentration sensor based on the amount of movement of the piston 22 detected by the movement detection sensor 30.

[0138] Furthermore, the second predetermined time may be defined as the time required for all of the subject's exhaled breath in the second bag 12 to be expelled, even if the amount of exhaled breath in the second bag 12 is equal to or greater than the second predetermined amount.

[0139] Furthermore, when the dispensing unit 51 dispenses the subject's exhaled breath from the second bag 12, the drive amount of the dispensing unit 51 may be changed so that the amount of change per unit time of the subject's exhaled breath dispensed to the CO sensor 52 and the He sensor 53 does not fall below a predetermined change amount.

[0140] Furthermore, the control device 40 does not have to perform at least one of the corrections using the first correction coefficient and the correction using the second correction coefficient.

[0141] Furthermore, the control device 40 may make a determination in steps S2 and S15 based on changes in the subject's exhaled and inhaled air volume. For example, in step S2, the control device 40 may determine whether the amount of decrease in exhaled air volume when the subject's exhaled air volume decreases continuously is greater than or equal to a predetermined amount.

[0142] For example, if the subject is exhaling during the first exhalation process in step S1, the subject's exhaled volume increases as shown in the spirogram in Figure 4 (NO in step S2). On the other hand, if the operator determines that the exhaled volume has reached the maximum exhalation level based on the spirogram displayed on the display device 2, they inform the subject to inhale. As the subject inhales continuously, the subject's exhaled volume decreases continuously until the amount of decrease in exhaled volume is greater than or equal to a predetermined decrease (YES in step S2).

[0143] Furthermore, in step S15, the control device 40 may determine whether the increase in the subject's inspiratory volume when it continuously increases is greater than or equal to a predetermined increase. If the subject is exhaling due to the third exhalation process in step S13, the subject's inspiratory volume decreases (NO in step S15). On the other hand, for example, if the subject inhales after completely exhaling, the subject's inspiratory volume increases continuously and the increase in said inspiratory volume becomes greater than or equal to a predetermined increase (YES in step S15).

[0144] Furthermore, the control device 40 may determine in step S24 whether or not a second predetermined signal has been acquired. The second predetermined signal is the ON signal for the second switch 62. If the operator determines that the analysis cannot be performed properly based on the fact that the rate of change per unit time of the volume of the second space R2 shown in Figure 7 has become relatively small before the second predetermined time has elapsed, the operator turns on the second switch 62. If the second switch 62 is turned on (YES in step S24), correction is performed using the second correction coefficient (step S25).

[0145] Furthermore, even though it is determined in step S14 of the sampling process shown in Figure 5 that the second discharge amount Br2 is equal to or greater than the second predetermined amount (YES in step S14), there are cases in which the change in the amount of analysis per unit time is less than or equal to the predetermined change in step S24 of the analysis process shown in Figure 6 (YES in step S24).

[0146] This phenomenon occurs because, even though the second discharge volume Br2 is determined to be equal to or greater than the second predetermined volume in step S14 of the sampling process (YES in step S14), the actual amount of exhaled breath from the subject injected into the second bag 12 (hereinafter referred to as the actual sample volume) is less than the second predetermined volume. Specifically, this phenomenon occurs, for example, due to aging of the second valve V2 and the third valve V3, causing the operation timing of the second valve V2 and the third valve V3 to lag behind the output timing of the control signal in step S13.

[0147] If the actual sample volume is less than the second predetermined volume, the change in the volume of the second space R2 becomes smaller from the time when the dispensing device 51 starts to operate (time t11) and before the second predetermined time has elapsed (time t20), as shown by the dashed line in Figure 7. In this case, the actual sample volume corresponds to the amount of analysis A2 equal to the decrease in the volume of the second space R2 from the time when the dispensing device 51 starts to operate (time t11) until the time when the change in the amount of analysis (the amount of exhaled breath from the subject sent to the CO sensor 52 and He sensor 53) per unit time becomes less than or equal to the predetermined change (time t20). The actual sample volume is insufficient compared to the second predetermined volume by the amount obtained by subtracting the actual sample volume from the second predetermined volume (hereinafter referred to as the deficit).

[0148] Therefore, the control device 40 replaces the first predetermined amount in step S12 with the third predetermined amount and the second predetermined amount in step S14 with the fourth predetermined amount so that the actual sample volume in subsequent DLco inspections is equal to or greater than the second predetermined amount. The third predetermined amount is the amount obtained by subtracting the deficit from the first predetermined amount. The fourth predetermined amount is the amount obtained by adding the deficit to the second predetermined amount. As a result, in subsequent DLco inspections, even if the operating timing of the second valve V2 and the third valve V3 is adjusted in step S13 and the operating timing of the second valve V2 and the third valve V3 lags behind the output timing of the control signal, the actual sample volume is adjusted to be equal to or greater than the second predetermined amount.

[0149] According to this modified version, the pulmonary function measuring device 1 further comprises a third connecting tube L3 that connects a mouthpiece MP into which the subject's exhaled breath is blown to a second bag 12, and a second valve V2 located in the third connecting tube L3 and opening and closing the third connecting tube L3. When the subject's exhaled breath is blown into the mouthpiece MP, the control device 40 controls the operating timing of the second valve V2 so that the amount of the subject's exhaled breath (actual sample amount) injected into the second bag 12 becomes a second predetermined amount based on the amount of movement of the piston 22 detected by the movement amount detection sensor 30. If the amount of the subject's exhaled breath (analyzed amount) sent to the CO sensor 52 and He sensor 53 is less than the second predetermined amount, the control device 40 adjusts the operating timing of the second valve V2 so that the amount of the subject's exhaled breath injected into the second bag 12 increases.

[0150] According to this, for example, if the operating timing of the second valve V2 is delayed relative to the output timing of the control signal due to aging of the second valve V2, the actual sample volume decreases, and even if the amount to be analyzed is less than the second predetermined amount, the operating timing of the second valve V2 is adjusted so that the actual sample volume increases. This makes it possible to increase the amount to be analyzed.

[0151] Furthermore, if the control device 40 adjusts the operating timing of the second valve V2 so that the amount of exhaled air from the subject injected into the second bag 12 increases, it may leave the first predetermined amount in step S12 as the first predetermined amount and replace the second predetermined amount in step S14 with the fourth predetermined amount.

[0152] <Second Embodiment> Next, the pulmonary function measuring device 1 according to the second embodiment of this disclosure will be described, primarily in terms of its differences from the pulmonary function measuring device 1 according to the first embodiment described above.

[0153] Figure 9 shows the configuration of the lung function measuring device 1 according to the second embodiment of this disclosure. The lung function measuring device 1 of this second embodiment does not include a first valve V1, a second container 20, a displacement detection sensor 30, and a three-way valve Vt.

[0154] Furthermore, in the lung function measuring device 1 of the second embodiment, the first end L1a of the first connecting tube L1 is connected to the first space R1, and the second end L1b of the first connecting tube L1 is open to the atmosphere. In addition, in the lung function measuring device 1 of the second embodiment, the second end L2b of the second connecting tube L2 is open to the atmosphere.

[0155] Furthermore, the lung function measuring device 1 of this second embodiment includes a flow sensor 170 located in the first connecting tube L1. The flow sensor 170 detects the flow rate (flow rate per unit time) of the gas flowing through the first connecting tube L1.

[0156] Specifically, the flow sensor 170 detects the flow rate of gas released from the first space R1 into the atmosphere via the first connecting pipe L1, and the flow rate of air flowing into the first space R1 via the first connecting pipe L1. The detection results of the flow sensor 170 are transmitted to the control device 40.

[0157] When the subject's exhaled breath flows from the mouthpiece MP into the first space R1, the gas in the first space R1 is released into the atmosphere via the first connecting tube L1. Similarly, when the subject's exhaled breath flows from the mouthpiece MP into the second bag 12, the second bag 12 expands, releasing the gas in the first space R1 into the atmosphere via the first connecting tube L1. In other words, the flow rate of the subject's exhaled breath flowing into the first space R1 and the flow rate of the subject's exhaled breath flowing into the second bag 12 are detected by the flow sensor 170.

[0158] Furthermore, the control device 40 can calculate the amount of exhaled breath from the subject flowing into the first space R1 and the amount of exhaled breath from the subject flowing into the second bag 12 by integrating the detection results of the flow sensor 170 over time.

[0159] Furthermore, when the subject inhales gas in the first space R1 through the mouthpiece MP, air flows into the first space R1 via the first connecting tube L1. When the subject inhales the test gas in the first bag 11 through the mouthpiece MP, the first bag 11 contracts, allowing air to flow into the first space R1 via the first connecting tube L1. Additionally, when the subject's exhaled breath in the second bag 12 is delivered to the CO sensor 52 and He sensor 53 by the delivery device 51, the second bag 12 contracts, allowing air to flow into the first space R1 via the first connecting tube L1. In other words, the flow rate of the gas inhaled by the subject in the first space R1, the flow rate of the test gas in the first bag 11 inhaled by the subject, and the flow rate of the subject's exhaled breath delivered from the second bag 12 by the delivery device 51 are detected by the flow sensor 170.

[0160] Furthermore, the control device 40 can calculate the amount of gas in the first space R1 inhaled by the subject, the amount of test gas in the first bag 11 inhaled by the subject, and the amount of exhaled breath from the subject delivered from the second bag 12 by the delivery device 51 by integrating the detection results of the flow sensor 170 over time.

[0161] Therefore, the control device 40 can generate the spirogram shown in Figure 4 based on the detection results of the flow sensor 170, similar to the control device 40 of the first embodiment described above. Furthermore, the control device 40 can use the detection results of the flow sensor 170 to execute the flowcharts shown in Figures 3, 5, and 6, similar to the control device 40 of the first embodiment described above, and perform DLco inspection.

[0162] As described above, according to this second embodiment, the pulmonary function measuring device 1 comprises a first container 10 having a first space R1, an expandable second bag 12 placed in the first space R1 into which the exhaled breath of a subject who has inhaled a test gas in a pulmonary function test is injected, a first connecting pipe L1 whose first end L1a is connected to the first space R1 and whose second end L1b is open to the atmosphere, a flow sensor 170 placed in the first connecting pipe L1, a second connecting pipe L2 whose first end L2a is connected to the second bag 12 and whose second end L2b is open to the atmosphere, a CO sensor 52 and a He sensor 53 placed in the second connecting pipe L2 for detecting the concentration of gases contained in the subject's exhaled breath in a pulmonary function test, a dispensing device 51 placed in the second connecting pipe L2 for dispensing the subject's exhaled breath in the second bag 12 to the CO sensor 52 and the He sensor 53, and a control device 40. The control device 40 calculates the amount of exhaled breath from the subject to be sent to the CO sensor 52 and the He sensor 53 based on the detection results of the flow sensor 170.

[0163] According to this, during a lung function test, when the subject's exhaled air in the second bag 12 is delivered to the CO sensor 52 and He sensor 53 via the second connecting tube L2 by the delivery device 51, the second bag 12 contracts, and air flows into the first space R1 via the first connecting tube L1. The control device 40 derives the amount of the subject's exhaled air delivered to the CO sensor 52 and He sensor 53 based on the detection result of the flow sensor 170. The amount of the subject's exhaled air delivered to the CO sensor 52 and He sensor 53 corresponds to the amount of the subject's exhaled air (analyzed amount) used in the lung function test. In this way, the lung function measuring device 1 can detect the amount of the subject's exhaled air used in the lung function test. [Explanation of symbols]

[0164] 1. Pulmonary function measurement device 10 1st container 11 First Bag 12. Second bag (bag) 20 Second container 21 Cylinder 22 pistons 23 Diaphragm 30 Movement detection sensor 40 Control device 51 Delivery machine 52 CO sensor (concentration sensor) 53 He sensor (concentration sensor) 61. Switch 1 62. Second switch (switch) 170 Flow Sensor L1 First connecting pipe L1a First connecting pipe, end 1 L1b Second end of the first connecting pipe L2 Second connecting pipe L2a First end of the second connecting pipe L2b Second end of the second connecting pipe L3 Third connecting pipe L3a Third connecting pipe section R1 First Space R2 2nd space V1 First Valve V2 2nd valve Vt Three-way valve (atmospheric vent)

Claims

1. A first container having a first space, The first space is provided with an expandable bag into which the exhaled breath of a subject who has inhaled a test gas during a lung function test is injected, A second container comprising a cylinder, a piston movably disposed relative to the cylinder, and a flexible diaphragm disposed between the cylinder and the piston, A movement amount detection sensor for detecting the amount of movement of the piston relative to the cylinder, A first connecting pipe that connects the second space surrounded by the cylinder and the piston to the first space, A second connecting pipe whose first end is connected to the bag, A concentration sensor is placed in the second connecting tube and detects the concentration of gases contained in the subject's exhaled breath during the lung function test, A dispensing device is arranged in the second connecting tube and sends the subject's exhaled breath from the bag to the concentration sensor, A control device is provided, The control device derives the amount of exhaled breath from the subject to be sent to the concentration sensor based on the amount of movement of the piston detected by the movement detection sensor. Lung function measurement device.

2. The second connecting pipe is positioned on the second end side of the concentration sensor and has an atmospheric vent that releases the subject's exhaled breath to the atmosphere when the discharger sends the subject's exhaled breath to the concentration sensor. The lung function measuring device according to claim 1.

3. The system further comprises a first valve, which is positioned in the first connecting pipe and opens and closes the first connecting pipe, The second end of the second connecting pipe is connected to the second space, When the exhaled breath of the subject in the bag is delivered to the concentration sensor by the delivery device, the control device closes the first connecting tube with the first valve. The lung function measuring device according to claim 1.

4. A third connecting tube connects the mouthpiece into which the subject's exhaled breath is blown to the bag, The system further comprises a second valve located in the third connecting pipe and for opening and closing the third connecting pipe, The control device is When the subject's exhaled breath is blown into the mouthpiece, the operation timing of the second valve is controlled so that the amount of the subject's exhaled breath injected into the bag is a predetermined amount, based on the amount of movement of the piston detected by the movement detection sensor. The second valve closes the third connecting tube, and the subject's exhaled breath in the bag is sent to the concentration sensor by the delivery device. The concentration of the gas detected by the concentration sensor is multiplied by the first correction coefficient of the following formula (1). The lung function measuring device according to claim 1. C1=(Q1+Q2) / Q1...(1) C1 is the first correction coefficient, Q1 is the predetermined amount, and Q2 is the volume of the portion between the second valve and the bag in the third connecting pipe.

5. When the exhaled breath of the subject in the bag is being delivered to the concentration sensor by the delivery device, the control device multiplies the concentration of the gas detected by the concentration sensor by a second correction coefficient of the following formula (2), in lieu of the first correction coefficient, depending on whether the amount of change per unit time of the amount of exhaled breath delivered to the concentration sensor is less than or equal to a predetermined change. The lung function measuring device according to claim 4. C2=(Q3+Q2) / Q3...(2) C2 is the second correction coefficient, and Q3 is the amount of exhaled breath from the subject sent to the concentration sensor when the change in the amount of exhaled breath from the subject per unit time sent to the concentration sensor becomes less than or equal to a predetermined change.

6. A third connecting tube connects the mouthpiece into which the subject's exhaled breath is blown to the bag, The system further comprises a second valve located in the third connecting pipe and for opening and closing the third connecting pipe, The control device is When the subject's exhaled breath is blown into the mouthpiece, the operation timing of the second valve is controlled so that the amount of the subject's exhaled breath injected into the bag is a predetermined amount, based on the amount of movement of the piston detected by the movement detection sensor. If the amount of exhaled breath from the subject sent to the concentration sensor is less than the predetermined amount, the operating timing of the second valve is adjusted so that the amount of exhaled breath from the subject injected into the bag increases. The lung function measuring device according to claim 1.

7. A first container having a first space, The first space is provided with an expandable bag into which the exhaled breath of a subject who has inhaled a test gas during a lung function test is injected, A first connecting pipe, the first end of which is connected to the first space and the second end of which is open to the atmosphere, A flow sensor is placed in the first connecting pipe, A second connecting pipe, the first end of which is connected to the bag and the second end of which is open to the atmosphere, A concentration sensor is placed in the second connecting tube and detects the concentration of gases contained in the subject's exhaled breath during the lung function test, A dispensing device is arranged in the second connecting tube and sends the subject's exhaled breath from the bag to the concentration sensor, A control device is provided, The control device calculates the amount of the subject's exhaled breath sent to the concentration sensor based on the detection result of the flow sensor. Lung function measurement device.

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