Pulmonary function measuring device

Abstract

Detecting the amount of exhaled air of a subject used in a pulmonary function test in a pulmonary function measuring device. [Solution] The pulmonary function measuring device (1) is disposed in a first space (R1) and comprises: an expandable second bag (12) 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) and a piston (22) disposed movably relative to the cylinder (21); a movement detection sensor (30) that detects the amount of movement of the piston (22); a first connecting tube (L1) that connects the second space (R2) surrounded by the cylinder (21) and the piston (22) to the first space (R1); a second connecting tube (L2) whose first end (L2a) is connected to the second bag (12); a CO sensor (52) and a He sensor (53) disposed in the second connecting tube (L2) that detect gas concentrations; and a control device (40) that derives the amount of exhaled breath of 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).

Description

[Technical Field]

[0001] The present disclosure relates to a pulmonary function measuring device. [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] In addition, in a lung diffusion capacity test, a valve disposed in the piping is turned on and off to control the first fixed amount (e.g., 750 ml) of the subject's exhaled breath to be exhaled into a balloon box, and the next fixed amount (sample volume: e.g., 1000 ml) is stored in a breath bag. The subject's exhaled breath stored in the breath bag is sent to the piping where a CO analyzer and a He analyzer are disposed. In this way, the subject's exhaled breath stored in the breath bag is used in a pulmonary function test. [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] However, due to variations in the timing of the valve's on / off operation and the subject's small exhaled air volume to begin with, there is a possibility that the amount of exhaled air stored in the exhalation bag may be insufficient. The subject's exhaled air in the bag is used for pulmonary function testing. If the amount of exhaled air (sample volume) in the bag is insufficient, appropriate test results may not be obtained. Therefore, there is a demand for a way to confirm the amount of exhaled air used in pulmonary function testing.

[0007] An object of the present disclosure is to provide a pulmonary function measuring device capable of detecting the amount of exhaled air of a subject used in a pulmonary function test. [Means for solving the problem]

[0008] a first connecting tube connecting a second space surrounded by the cylinder and the piston to the first space; a second connecting tube having a first end connected to the bag; a concentration sensor disposed on the second connecting tube for detecting a concentration of gas contained in the exhaled breath of the subject during the pulmonary function test; a sender disposed on the second connecting tube for sending the exhaled breath of the subject in the bag to the concentration sensor; and a control device. The control device derives the amount of exhaled breath of the subject to be sent to the concentration sensor based on the movement of the piston detected by the movement detection sensor.

[0009] 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 during a pulmonary function test, the amount of gas in the second space can be changed. The piston moves due to the 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 movement of the piston detected by the movement amount 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 pulmonary function test. In this way, the pulmonary function measuring device can detect the amount of the subject's exhaled breath used in the pulmonary function test.

[0010] In addition, in a pulmonary function measuring device according to one embodiment of the present disclosure, the second connecting tube is positioned closer to the second end than the concentration sensor, and has an atmosphere opening portion that releases the subject's exhaled breath into the atmosphere when the sender sends the subject's exhaled breath to the concentration sensor.

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

[0012] Furthermore, a pulmonary function measuring device according to one embodiment of the present disclosure further includes a first valve disposed in the first connecting tube for opening and closing the first connecting tube, a second end of the second connecting tube being connected to the second space, and the control device causing the first valve to close the first connecting tube when the exhaled breath of the subject in the bag is sent to the concentration sensor by the sender.

[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 movement of the piston 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 testing pulmonary function) based on the amount of movement of the piston detected by the movement amount detection sensor.

[0014] Furthermore, a pulmonary function measuring device according to one embodiment of the present disclosure further includes a third connecting tube connecting the bag to a mouthpiece into which the subject's exhaled breath is blown, and a second valve disposed on the third connecting tube and configured to open and close the third connecting tube. When the subject's exhaled breath is blown into the mouthpiece, the control device controls the operation timing of the second valve based on the movement of the piston detected by the movement detection sensor so that a predetermined amount of the subject's exhaled breath is injected into the bag, closes the third connecting tube using the second valve, sends the subject's exhaled breath in the bag to the concentration sensor using the sender, and multiplies the concentration of the gas detected by the concentration sensor by a first correction coefficient of the following equation (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 of the third connecting tube between the second valve and the bag.

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

[0016] Furthermore, in a pulmonary 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 sender, the control device multiplies the concentration of the gas detected by the concentration sensor by a second correction coefficient of the following equation (2) instead of the first correction coefficient, in response to the change per unit time in the amount of the subject's exhaled breath sent to the concentration sensor being less than a predetermined change amount. C2=(Q3+Q2) / Q3 (2) C2 is the second correction coefficient, and Q3 is the amount of the subject's exhaled breath delivered to the concentration sensor when the change per unit time in the amount of the subject's exhaled breath delivered to the concentration sensor becomes less than a predetermined change amount.

[0017] The smaller the volume of the subject's exhaled breath in the bag when the test begins, the greater the ratio of the volume of the portion of the third connecting tube between the second valve and the bag to the volume of the subject's exhaled breath in the bag, and the greater the decrease in the concentration of the subject's exhaled breath. In other words, the smaller the volume of the subject's exhaled breath in the bag when the test begins, the greater the possibility of the test accuracy decreasing. Furthermore, when the volume of the subject's exhaled breath in the bag is being delivered to the concentration sensor, if the volume becomes relatively small, the rate of change per unit time of the volume of the subject's exhaled breath delivered to the concentration sensor decreases. Therefore, when the rate of change per unit time of the volume of the subject's exhaled breath delivered to the concentration sensor is equal to or less than a predetermined rate of change, the control device multiplies the concentration of the gas detected by the concentration sensor by a second correction coefficient instead of the first correction coefficient. Q3 in Equation (2) is the volume of the subject's exhaled breath delivered to the concentration sensor when the rate of change per unit time of the volume of the subject's exhaled breath delivered to the concentration sensor becomes equal to or less than the predetermined rate of change. This allows the pulmonary function measuring device to improve the accuracy of the test even when the amount of exhaled air from the subject in the bag is less than a predetermined amount.

[0018] In addition, a pulmonary function measuring device according to one aspect of the present disclosure further includes a third connecting tube connecting the bag to a mouthpiece into which the subject's exhaled breath is blown, and a second valve disposed on the third connecting tube for opening and closing the third connecting tube, wherein when the subject's exhaled breath is blown into the mouthpiece, the control device controls the operation timing 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 movement amount of the piston detected by the movement amount detection sensor, and adjusts the operation timing 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] With this, even if the amount of the subject's breath injected into the bag decreases and the amount of the subject's breath delivered to the concentration sensor is less than a predetermined amount due to, for example, the operation timing of the second valve being delayed relative to the output timing of the control signal due to aging of the second valve, the operation timing of the second valve is adjusted so that the amount of the subject's breath injected into the bag increases, thereby increasing the amount of the subject's breath delivered to the concentration sensor.

[0020] a flow sensor disposed on 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 disposed on the second connecting tube and detecting a concentration of gas contained in the exhaled breath of the subject during the pulmonary function test; a sender disposed on the second connecting tube and sending the exhaled breath of the subject in the bag to the concentration sensor; and a control device, wherein the control device calculates the amount of exhaled breath of the subject to be sent to the concentration sensor based on the detection result of the flow sensor.

[0021] According to this, when the breath of the subject in the bag is delivered by the delivery device to the concentration sensor via the second connecting tube during a pulmonary function test, the bag contracts and air flows into the first space via the first connecting tube. The control device calculates the amount of breath of the subject delivered to the concentration sensor based on the detection result of the flow sensor. The amount of breath of the subject delivered to the concentration sensor corresponds to the amount of breath of the subject used in the pulmonary function test. In this way, the pulmonary function measuring device can detect the amount of breath of the subject used in the pulmonary function test. [Effects of the Invention]

[0022] According to the present disclosure, the pulmonary function measuring device can detect the amount of exhaled breath of a subject used in a pulmonary function test. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram showing the configuration of a pulmonary function measuring device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a block diagram of the pulmonary function measuring device shown in FIG. [Figure 3] FIG. 3 is a flowchart showing the process executed by the control device when a DLco check is performed. [Figure 4] FIG. 4 shows a spirogram when a DLco test is performed. [Figure 5] FIG. 5 is a flowchart of the collection process executed by the control device. [Figure 6] FIG. 6 is a flowchart of the analysis process executed by the control device. [Figure 7] FIG. 7 is a diagram showing the amount of exhaled air of the subject sent to the CO sensor and the He sensor. [Figure 8] FIG. 8 is a diagram showing the dilution ratio of carbon monoxide and the dilution ratio of helium displayed on the display device. [Figure 9] FIG. 9 is a diagram showing the configuration of a pulmonary function measuring device according to the second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0024] 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.

[0025] First Embodiment Fig. 1 is a diagram showing the configuration of a pulmonary function measuring device 1 according to a first embodiment of the present disclosure. The pulmonary function measuring device 1 is a device that measures the pulmonary function of a subject. The pulmonary function measuring device 1 of this first embodiment can perform a pulmonary diffusion capacity test using carbon monoxide (hereinafter referred to as a DLCO test) and a functional residual capacity test (hereinafter referred to as an FRC test).

[0026] The pulmonary function measuring device 1 includes 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 movement detection sensor 30, and a control device 40.

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

[0028] A first bag 11 and a second bag 12 (corresponding to "bags") are disposed in the first space R1 of the first container 10. The first bag 11 and the second bag 12 are expandable. That is, the first bag 11 and the second bag 12 expand when gas is injected into them and contract when the gas is discharged.

[0029] The test gas, which is the gas inhaled by the subject, is injected into the first bag 11. 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).

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

[0031] In a pulmonary function test, the breath of a subject who has inhaled test gas is injected into the second bag 12. The second bag 12 is connected via a third connecting pipe L3 to a mouthpiece MP into which the breath of the subject is blown. A second valve V2, which is an electromagnetic valve that opens and closes the third connecting pipe L3, is disposed in the third connecting pipe L3.

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

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

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

[0035] A second check valve Vr2 is disposed in the second branch pipe Ld2 between the second branch part 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, but blocks gas from flowing in the opposite direction.

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

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

[0038] The piston 22 integrally includes a disk portion 22a and a shaft member 22b. The disk portion 22a is located inside the cylinder 21. The shaft member 22b is disposed so as to extend toward the outside of the cylinder 21 along the central axis of the cylinder 21. The space surrounded by the cylinder 21 and the disk portion 22a of the piston 22 corresponds to the second space R2.

[0039] The diaphragm 23 is disposed 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 disk 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 movement amount detection sensor 30 detects the amount of movement of the piston 22 relative to the cylinder 21. The movement amount detection sensor 30 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 the piston 22. The detection result of the movement amount detection sensor 30 is output to the control device 40. The movement amount detection sensor 30 may also be a linear encoder.

[0041] The second container 20 is used for an FRC test. A 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 of the cylinder 21. The amount of exhaled breath of the subject 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 exhaled breath of the subject 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] A first end L2a of the second connecting pipe L2 is connected to the second bag 12. A second end L2b of the second connecting pipe L2 is connected to the second space R2. 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 release section") are arranged in the second connecting pipe L2. The dispenser 51, the CO sensor 52, the He sensor 53, and the 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 sender 51 sends the exhaled breath of the subject in the second bag 12 to the CO sensor 52 and the He sensor 53 (details will be described later). The sender 51 is, for example, a pump and a blower.

[0045] The CO sensor 52 and the He sensor 53 detect the concentrations of gases contained in the breath of the subject during a pulmonary function test. The CO sensor 52 detects the concentration of carbon monoxide during a pulmonary function test. The He sensor 53 detects the concentration of helium during a pulmonary function test.

[0046] The three-way valve Vt is a three-way valve that has a first communication state in which the second bag 12 communicates with the second space R2 and a second communication state in which the second bag 12 communicates with the atmosphere. When the three-way valve Vt is in the first communication state, the second space R2 does not communicate with the atmosphere. When the three-way valve Vt is in the second communication state, the second space R2 does not communicate with the atmosphere and the second bag 12 does not communicate with the second space R2.

[0047] FIG. 2 is a block diagram of the pulmonary function measuring device 1 shown in FIG.

[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), 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.

[0049] The control device 40 acquires the detection results of the movement amount detection sensor 30, the CO sensor 52, and the He sensor 53. The control device 40 controls the sender 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 the test results and the like on the display device 2 (such as a display).

[0050] Pulmonary function measuring device 1 also includes first switch 61 and second switch 62 that are turned on by the operator. First switch 61 and second switch 62 are switches that output an ON signal when turned on (for example, automatic return push switches). First switch 61 and second switch 62 may be capacitance-type touch switches, or, if display device 2 includes a touch panel, may be touch switches formed on the touch panel.

[0051] The first switch 61 is a switch for proceeding with the DLco inspection process. The second switch 62 will be described in detail later. The ON signals of the first switch 61 and the second switch 62 are sent to the control device 40.

[0052] Next, the operation of the pulmonary function measuring device 1 when a DLCO test is performed will be described.

[0053] Fig. 3 is a flowchart executed by the control device 40 when a DLCO test is performed. Fig. 4 is a diagram showing a spirogram when a DLCO test is performed. The horizontal axis in Fig. 4 represents time. On the vertical axis in Fig. 4, the side above (the side indicated by the arrow) a reference position P0 (corresponding to the resting expiratory position) indicated by zero (0) corresponds to the inhaled air volume, and the side below (the side opposite to the side indicated by the arrow) the reference position P0 corresponds to the exhaled air volume.

[0054] Before the DLCO test begins (before time t1: Figure 4), the first bag 11 contains test gas, and the second bag 12 is in a deflated state, with most of the gas in the second bag 12 having been sucked in. 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 state, the mouthpiece MP is connected to the first space R1 via the first check valve Vr1 and the third valve V3, and to the first space R1 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. The three-way valve Vt is in a second communicating state, connecting the second bag 12 to the atmosphere.

[0055] Before the DLCO test begins (before time t1: Figure 4), the subject breathes quietly with the mouthpiece MP in his / her mouth. At this time, the subject breathes using the gas in the first space R1 and the second space R2.

[0056] At this time, piston 22 moves in response to the subject's breathing. The amount of movement of piston 22 corresponds to the amount of breath inhaled by the subject (the subject's inhaled air amount) and the amount of breath exhaled by the subject (the subject's exhaled air amount). Control device 40 can calculate the amount of breath inhaled and exhaled by the subject in real time by multiplying the detection result of movement amount detection sensor 30 (the movement amount of piston 22) by the cross-sectional area of ​​cylinder 21. Control device 40 generates a spirogram (FIG. 4) based on the detection result of movement amount detection sensor 30 and displays it on display device 2 in real time.

[0057] When the DLCO test is started, the control device 40 executes a first exhalation process in step S1 shown in Fig. 3. The first exhalation process is a process in which the subject exhales to the maximum expiratory level. In the first exhalation process, the control device 40 closes the fifth valve V5 and displays on the display device 2 a message to exhale forcefully.

[0058] The subject exhales forcefully in response to the display on the display device 2. This causes the subject's exhaled air to flow into the first space R1 via the first check valve Vr1 and the third valve V3, and the gas in the first space R1 moves to the second space R2 via the first connecting pipe L1, causing the piston 22 to move toward the opening M of the cylinder 21. At this time, in Figure 4, the amount of inspiration decreases from the time (time t1) when the subject starts exhaling, and the amount of expiration increases beyond the reference position P0.

[0059] Next, the control device 40 determines whether or not a first predetermined signal has been acquired in step S2 shown in Fig. 3. The first predetermined signal is an ON signal for the first switch 61. If the control device 40 has not acquired the first predetermined signal (NO in step S2), the control device 40 repeatedly executes step S2.

[0060] When the operator determines that the expiratory volume has reached the maximum expiratory level based on the spirogram (FIG. 4) displayed on the display device 2, he or she turns on the first switch 61. When the control device 40 receives an on signal from the first switch 61 (YES in step S2), the control device 40 causes the program to proceed to step S3.

[0061] In step S3, the control device 40 executes an inhalation process. The inhalation process is a process for having the subject inhale the test gas. In the inhalation process, the control device 40 closes the third valve V3, opens the fourth valve V4, and displays on the display device 2 a message to inhale forcefully.

[0062] In response to the display on the display device 2, the subject inhales forcefully. 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 into the first space R1 via the first connecting tube L1, and the piston 22 moves toward the bottom surface B of the cylinder 21. At this time, in FIG. 4, the exhalation volume decreases from the time (time t2) when the subject starts inhaling the test gas, and the inhalation volume increases beyond the reference position P0.

[0063] Next, in step S4 shown in Fig. 3, the control device 40 determines whether a first predetermined time has elapsed. The first predetermined time is the time required for 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] When the operator determines that the inhalation volume has reached the maximum inhalation level based on the spirogram (Figure 4) displayed on the display device 2, he instructs the subject to stop breathing. As shown in Figure 4, from the point when the subject stops breathing (time t3), the subject's inhalation volume is maintained at approximately the maximum inhalation level. 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 causes the program to proceed to step S5.

[0066] The control device 40 executes a sampling process in step S5. The sampling process is a process for sampling the exhaled air of a subject who has inhaled a test gas for use in a pulmonary function test.

[0067] 5 is a flowchart of the collection process executed by the control device 40. In step S11, the control device 40 executes a second exhalation process. The second exhalation process is a process in which the subject exhales forcefully to cause the subject's exhaled breath to flow into the first space R1.

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

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

[0070] 5, the control device 40 determines whether the first discharge amount Br1 is equal to or greater than a first predetermined amount. The first discharge amount Br1 is the amount of breath exhaled by the subject from the time when the subject starts to exhale (time t4). The control device 40 calculates the first discharge amount Br1 based on the amount of movement of the piston 22 from the time when the subject starts to exhale (time t4).

[0071] The first predetermined amount is determined based on the standard set by the American Thoracic Society (ATS). The first predetermined amount is, for example, 750 ml. The first predetermined amount is stored in advance in the memory unit 41 (FIG. 2) of the control device 40.

[0072] The total volume of the mouthpiece MP, the volume of the third connecting pipe L3 between the mouthpiece MP and the first branch D1, and the volume of the first branch pipe Ld1 between the first branch D1 and the third valve V3 is smaller than the first predetermined volume, so that the gas between the mouthpiece MP and the third valve V3 is discharged into the first space R1.

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

[0074] The control device 40 executes a third exhalation process in step S13. The third exhalation process is a process in which the exhaled air of the subject flows (injects) 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 a closed state and switches the second valve V2 to an open state. This causes the exhaled air of the subject to flow 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 of the cylinder 21. At this time, in FIG. 4, the intake air amount further decreases from the time (time t5) when the second valve V2 is switched to the open state.

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

[0077] The second predetermined amount is determined based on the standard value set by the American Thoracic Society (ATS). The second predetermined amount is, for example, 1000 ml. The second predetermined amount is stored in the memory unit 41 in advance.

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

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

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

[0081] The control device 40 executes a fourth exhalation process in step S16. In the fourth exhalation process, the control device 40 closes the second valve V2 and opens the third valve V3. When the second discharge rate Br2 is equal to or greater than the second predetermined rate (YES in step S14) and the subject continues to exhale, the exhaled air of the subject who has inhaled the test gas flows into the first space R1, and the gas in the first space R1 moves further into the second space R2 via the first connecting tube L1, causing the piston 22 to move further toward the opening M of the cylinder 21. In this case, in FIG. 4, the inhalation rate further decreases from the time (time t6) when the third valve V3 is opened, and the exhaled air rate increases beyond the reference position P0.

[0082] On the other hand, when 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 inhalation amount increases, for example, when the subject inhales (not shown).

[0083] In this way, the breath of the subject who has inhaled the test gas is collected in the second bag 12. The breath of the subject in the second bag 12 is used for testing pulmonary function. Hereinafter, the amount of breath of the subject injected into the second bag 12 may be referred to as the sample amount.

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

[0085] When the control device 40 completes the fourth exhalation process in step S16, it ends the collection process and causes the program to proceed to step S6 shown in FIG.

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

[0087] 6 is a flowchart of the analysis process executed by the control device 40. The control device 40 performs an analysis start process in step S21.

[0088] In the analysis start process, the control device 40 switches the sixth valve V6 to an open state. The control device 40 also drives the sender 51 at 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 communication state. As a result, the subject's exhaled breath in the second bag 12 is sent by the sender 51 through the second connecting pipe L2 to the CO sensor 52 and the He sensor 53, and then released into the atmosphere through the three-way valve Vt. The predetermined drive amount is a predetermined constant drive amount.

[0089] When the breath of the subject in the second bag 12 is delivered 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, in the analysis start process, the control device 40 starts deriving the amount of exhaled breath of 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 amount detection sensor 30 .

[0091] Fig. 7 is a diagram showing the amount of exhaled breath of the subject sent to the CO sensor 52 and the He sensor 53. In Fig. 7, the horizontal axis represents time, and the vertical axis represents the volume of the second space R2.

[0092] The piston 22 moves toward the bottom surface B of the cylinder 21 from the time (time t11) when the drive of the dispenser 51 starts, thereby reducing the volume of the second space R2. 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 amount detection sensor 30. The amount of change in the volume of the second space R2 from the time (time t11) when the drive of the dispenser 51 starts corresponds to the amount of exhaled breath of the subject delivered to the CO sensor 52 and the He sensor 53. In other words, the control device 40 calculates the amount of exhaled breath of the subject 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.

[0093] The volume of the subject's exhaled breath delivered to the CO sensor 52 and the He sensor 53 is the volume of the subject's exhaled breath used in the pulmonary function test, and corresponds to the volume of the subject's exhaled breath that has inhaled the test gas that is analyzed. Hereinafter, the volume of the subject's exhaled breath delivered to the CO sensor 52 and the He sensor 53 may be referred to as the "analysis volume." As described above, by driving the delivery device 51 at a predetermined drive volume, the volume of the second space R2 decreases at a constant rate. In other words, the analysis volume 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 using a time chart similar to that shown in FIG. 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, so that the CO sensor 52 detects the concentration of carbon monoxide contained in the subject's exhaled breath, and the He sensor 53 detects the concentration of helium contained in the subject's exhaled breath.

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

[0096] That is, the gas in region L3a reduces the concentrations of carbon monoxide and helium in the breath of the subject in second bag 12. In this case, the analysis of the breath of the subject may not be performed accurately.

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

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

[0099] C1 is the first correction coefficient, Q1 is the second predetermined amount, and Q2 is the capacity 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 the subject's breath in the second bag 12 is a second predetermined amount, the subject's breath in the second bag 12 is not diluted by the gas in the region L3a.

[0101] Furthermore, in the analysis start process, the control device 40 starts calculating the carbon monoxide dilution ratio. The carbon monoxide dilution ratio is the carbon monoxide concentration 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 the dilution ratio, it displays the maximum dilution ratio among the dilution ratios before the calculation 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] Fig. 8 is a diagram showing the dilution ratio of carbon monoxide and the dilution ratio of helium displayed on the display device 2. In Fig. 8, the horizontal axis represents time, and the vertical axis represents the dilution ratio.

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

[0106] In step S22 shown in FIG. 6, the control device 40 determines whether a second predetermined time has elapsed. The second predetermined time is set to a time sufficient for analyzing the subject's exhaled breath. The second predetermined time is set to a time during which not all of the subject's exhaled breath in the second bag 12 is discharged when the sender 51 is driven at a constant drive rate while the amount of the subject's exhaled breath in the second bag 12 is equal to or greater than the second predetermined amount. In other words, when the sender 51 is driven for the second predetermined time while the amount of the subject's exhaled breath in the second bag 12 is equal to or greater than the second predetermined amount, the analysis amount (analysis amount A1: FIG. 7) is smaller 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] 7, the volume of the second space R2 decreases at a constant rate from the time when the drive of the sender 51 starts (time t11) to the time when the drive of the sender 51 stops after the second predetermined time has elapsed (time t12). In this case, the analysis amount (the amount of the subject's exhaled breath delivered to the CO sensor 52 and the He sensor 53) corresponds to the analysis amount A1, which is equal to the amount of change in the volume of the second space R2 from the time when the drive of the sender 51 starts (time t11) to the time when the drive of the sender 51 stops after the second predetermined time has elapsed (time t12).

[0109] When the control device 40 stops the sender 51 in step S23, it ends the analysis process shown in Fig. 6 and terminates the program (Fig. 3). The operator checks the results of the DLco test based on the dilution ratio (Fig. 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 analysis amount (the amount of exhaled breath of the subject delivered to the CO sensor 52 and the He sensor 53) per unit time is equal to or less than a predetermined change. As described above, when the deliverer 51 is driven at a predetermined drive amount, the volume of the second space R2 decreases at a constant rate. In other words, the amount of exhaled breath of the subject delivered to the CO sensor 52 and the He sensor 53 (analysis amount) increases at a constant rate. In other words, the change in the analysis amount per unit time is approximately a constant value. The predetermined change amount is set to a value smaller than the constant value.

[0111] 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 second bag 12 is less than the second predetermined amount. In this case, the amount of the subject's exhaled breath in second bag 12 may become extremely small before the second predetermined time has elapsed in the analysis process.

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

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

[0114] If the amount of breath from the subject in second bag 12 becomes extremely small before the second predetermined time has elapsed, the actual dilution ratio will decrease from the point in time t20 when the rate of change in the analysis amount per unit time falls below the predetermined change, as shown by the dashed line in Figure 8, because the breath from the subject is no longer sent to CO sensor 52 and He sensor 53. However, as described above, because control device 40 displays the maximum value of the dilution ratio, the dilution ratio indicated by the solid line is displayed on display device 2.

[0115] If the analysis volume is relatively small, the analysis of the subject's breath may not be performed properly. Specifically, as the volume of the subject's breath in the second bag 12 decreases, the ratio of the volume of the subject's breath in the second bag 12 to the volume of the subject's breath in the second bag 12 increases, and the concentration of the subject's breath decreases significantly. This may reduce the accuracy of the dilution ratio shown in FIG. 8.

[0116] If there is still an amount of exhaled breath remaining in the second bag 12 and the change in the analytical amount per unit time is greater than the predetermined 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 change in the analytical amount per unit time is greater than the predetermined change, the control device 40 repeatedly executes steps S22 and S24.

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

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

[0119] C2 is the second correction coefficient, Q3 is the amount of exhaled breath (analysis amount) of the subject delivered to the CO sensor 52 and the He sensor 53 when the amount of change per unit time in the amount of exhaled breath of the subject delivered to the CO sensor 52 and the He sensor 53 becomes equal to or less than a predetermined amount of change, and Q2 is the capacity of the portion L3a of the third connecting tube L3 between the second valve V2 and the second bag 12. Q3 in equation (2) corresponds to the analysis 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 corrected to a state where it is not diluted by the gas in the region L3a. The control device 40 switches to the dilution ratio calculated using the carbon monoxide concentration and helium concentration corrected by the second correction coefficient, and displays it on the display device 2.

[0121] When the control device 40 ends the correction coefficient switching process in step S25, it stops the sender 51 in step S23. Then, the control device 40 ends the program as described above. In this case, the operator checks the results of the DLco test based on the corrected dilution ratio displayed on the display device 2. Note that if the change in the analysis amount per unit time becomes equal to or less than the predetermined change before the second predetermined time has elapsed (YES in step S24), the sender 51 is stopped and the analysis process is terminated early before the second predetermined time has elapsed.

[0122] As described above, according to the first embodiment, the pulmonary function measuring device 1 comprises a first container 10 having a first space R1, an expandable second bag 12 that is disposed in the first space R1 and into which the exhaled breath of a subject who has inhaled a test gas is injected during a pulmonary function test, a second container 20 that includes a cylinder 21, a piston 22 that is disposed movably relative to the cylinder 21, and a flexible diaphragm 23 that is disposed between the cylinder 21 and the piston 22, and a moving sensor that detects the amount of movement of the piston 22 relative to the cylinder 21. The test device includes an amount detection sensor 30, a first connecting pipe L1 connecting the first space R1 to a second space R2 surrounded by the cylinder 21 and the piston 22, a second connecting pipe L2 having a first end L2a connected to a bag, a CO sensor 52 and a He sensor 53 disposed on the second connecting pipe L2 and detecting the concentration of gas contained in the breath of the subject in a pulmonary function test, a sender 51 disposed on the second connecting pipe L2 and sending the breath of the subject in 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 breath of 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.

[0123] This allows the amount of gas in the second space R2 to be changed when the breath of the subject in the second bag 12 is delivered by the delivery device 51 to the CO sensor 52 and the He sensor 53 via the second connecting tube L2 during a pulmonary function test. The piston 22 moves in response to a change in the amount of gas in the second space R2. The control device 40 derives the amount of breath of the subject 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. The amount of breath of the subject delivered to the CO sensor 52 and the He sensor 53 corresponds to the amount of breath of the subject used in the pulmonary function test (analysis amount). In this way, the pulmonary function measuring device 1 can detect the amount of breath of the subject used in the pulmonary function test.

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

[0125] Furthermore, as described above, the second container 20 is used for the FRC test and is provided in advance in the pulmonary function measuring device 1. In other words, the pulmonary function measuring device 1 can detect the amount of exhaled breath of the subject used in the pulmonary function test by using the second container 20 used for the FRC test without adding any new components.

[0126] The second connecting pipe L2 is disposed closer to the second end L2b than the CO sensor 52 and the He sensor 53, and has a three-way valve Vt that releases the subject's exhaled breath into the atmosphere when the sender 51 sends the subject's exhaled breath to the CO sensor 52 and the He sensor 53.

[0127] According to this, when the breath of the subject in the second bag 12 is delivered by the delivery device 51 to the CO sensor 52 and the He sensor 53 via the second connecting tube L2, 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 when 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 the breath of the subject delivered to the CO sensor 52 and the He sensor 53. The control device 40 can reliably derive the amount of the breath of the subject delivered to the CO sensor 52 and the He sensor 53 (the amount of the breath of the subject used in the pulmonary function test (analysis amount)) based on the amount of movement of the piston 22 detected by the movement amount detection sensor 30.

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

[0129] During a pulmonary function test, gas in a portion L3a of the third connecting tube L3 between the second valve V2 and the bag mixes with the subject's exhaled breath in the second bag 12. This may reduce the concentration of the gas in the subject's exhaled breath, reducing the accuracy of the test. Therefore, the control device 40 multiplies the gas concentrations detected by the CO sensor 52 and the He sensor 53 by the first correction coefficient in equation (1). This allows the pulmonary 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) instead of the first correction coefficient, in response to the change per unit time in the amount of the subject's exhaled breath delivered to the CO sensor 52 and the He sensor 53 being equal to or less than a predetermined change amount.

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

[0132] Next, a pulmonary function measuring device 1 according to a modified example of the first embodiment of the present disclosure will be described.

[0133] For example, the pulmonary function measuring device 1 does not have to include the first valve V1.

[0134] Furthermore, the pulmonary function measuring device 1 does not necessarily have to include the three-way valve Vt. In this case, the second end L2b of the second connecting tube L2 is not connected to the second space R2 but is open to the atmosphere. That is, in this case, the second end L2b of the second connecting tube L2 corresponds to the "atmosphere-opening portion."

[0135] 6, the pulmonary function measuring device 1 may close the first valve V1 and set the three-way valve Vt to the first communication 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 of the cylinder 21. Then, as in the first embodiment, in the analysis start process, the control device 40 starts deriving the amount of the subject's exhaled breath 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 include the three-way valve Vt.

[0136] The pulmonary function measuring device 1 of this modification further includes a first valve V1 disposed on the first connecting tube L1 for opening and closing the first connecting tube L1. A second end L2b of the second connecting tube L2 is connected to the second space R2. When the sender 51 sends the exhaled breath of the subject in the second bag 12 to the CO sensor 52 and the He sensor 53, the control device 40 closes the first connecting tube L1 using the first valve V1.

[0137] According to this, when the breath of the subject in the second bag 12 is delivered by the deliverer 51 to the CO sensor 52 and the He sensor 53 via the second connecting tube L2, the breath of the subject 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 breath of the subject delivered to the CO sensor 52 and the He sensor 53. Therefore, the control device 40 can reliably derive the amount of breath of the subject delivered to the concentration sensor (analysis amount) based on the amount of movement of the piston 22 detected by the movement amount detection sensor 30.

[0138] In addition, the second predetermined time may be set to the time when all of the subject's exhaled breath in the second bag 12 is expelled, even when the amount of the subject's exhaled breath in the second bag 12 is equal to or greater than the second predetermined amount.

[0139] Furthermore, when the sender 51 sends out the subject's exhaled breath in the second bag 12, the driving amount of the sender 51 may be changed so that the change in the amount of the subject's exhaled breath sent to the CO sensor 52 and the He sensor 53 per unit time does not become less than a predetermined change amount.

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

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

[0142] For example, when the subject is exhaling due to the first exhalation process in step S1, the subject's exhalation volume increases as shown in the spirogram in Fig. 4 (NO in step S2). On the other hand, when the operator determines that the exhalation volume has reached the maximum expiratory level based on the spirogram displayed on display device 2, he or she tells the subject to inhale. As the subject continues to inhale, the subject's exhalation volume decreases continuously, and the decrease in the exhalation volume becomes equal to or greater than 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 inhalation volume when the inhalation volume of the subject continuously increases is equal to or greater than a predetermined increase. If the subject is exhaling due to the third exhalation process in step S13, the subject's inhalation volume decreases (NO in step S15). On the other hand, for example, if the subject inhales after completely exhaling, the subject's inhalation volume continuously increases and the increase in the inhalation volume becomes equal to or greater than a predetermined increase (YES in step S15).

[0144] Furthermore, the control device 40 may determine whether or not a second predetermined signal has been acquired in step S24. The second predetermined signal is an ON signal for the second switch 62. If the operator determines that the analysis is not being performed appropriately based on the fact that the amount of change per unit time in the volume of the second space R2 shown in FIG. 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 if it is determined in step S14 of the collection process shown in FIG. 5 that the second discharge amount Br2 is equal to or greater than the second predetermined amount (YES in step S14), a phenomenon may occur in which the change in the analysis amount per unit time is equal to or less than the predetermined change amount (YES in step S24) in step S24 of the analysis process shown in FIG. 6.

[0146] This phenomenon occurs when, in step S14 of the collection process, it is determined that the second discharge rate Br2 is equal to or greater than the second predetermined rate (YES in step S14), but the actual amount of the subject's breath injected into the second bag 12 (hereinafter referred to as the actual sample amount) is less than the second predetermined rate. Specifically, this phenomenon occurs when, for example, the operation timing of the second valve V2 and the third valve V3 is delayed relative to the output timing of the control signal in step S13 due to deterioration of the second valve V2 and the third valve V3 over time, etc.

[0147] When the actual sample volume is less than the second predetermined volume, as shown by the dashed line in Figure 7, the change in volume of the second space R2 decreases from the time when the drive of the sender 51 starts (time t11) and before the second predetermined time has elapsed (time t20). In this case, the actual sample volume corresponds to the analysis volume A2, which is equal to the decrease in volume of the second space R2 from the time when the drive of the sender 51 starts (time t11) to the time when the change per unit time in the analysis volume (the volume of the subject's exhaled breath delivered to the CO sensor 52 and the He sensor 53) becomes equal to or less than 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 shortage).

[0148] Therefore, the control device 40 replaces the first predetermined amount in step S12 with a third predetermined amount and replaces the second predetermined amount in step S14 with a fourth predetermined amount so that the actual sample amount in the next and subsequent DLco tests will be equal to or greater than the second predetermined amount. The third predetermined amount is the first predetermined amount minus the shortage amount. The fourth predetermined amount is the second predetermined amount plus the shortage amount. As a result, in the next and subsequent DLco tests, the operation timings of the second valve V2 and the third valve V3 are adjusted in step S13 so that the actual sample amount will be equal to or greater than the second predetermined amount even if the operation timings of the second valve V2 and the third valve V3 are delayed relative to the output timing of the control signals.

[0149] According to this modification, pulmonary function measuring device 1 further includes a third connecting pipe L3 that connects second bag 12 to mouthpiece MP, into which the subject's exhaled breath is blown, and a second valve V2 that is disposed on third connecting pipe L3 and opens and closes third connecting pipe L3. When the subject's exhaled breath is blown into mouthpiece MP, control device 40 controls the operation timing of second valve V2 based on the movement of piston 22 detected by movement detection sensor 30 so that the amount of the subject's exhaled breath injected into second bag 12 (actual sample amount) becomes a second predetermined amount, and adjusts the operation timing of second valve V2 so that the amount of the subject's exhaled breath injected into second bag 12 increases when the amount of the subject's exhaled breath delivered to CO sensor 52 and He sensor 53 (analysis amount) is less than the second predetermined amount.

[0150] With this, even if the actual sample volume decreases and the analysis volume is less than the second predetermined volume due to, for example, the operation timing of the second valve V2 being delayed relative to the output timing of the control signal due to aging of the second valve V2, the operation timing of the second valve V2 is adjusted so that the actual sample volume increases, thereby increasing the analysis volume.

[0151] In addition, when adjusting the operation timing of the second valve V2 so as to increase the amount of the subject's exhaled breath injected into the second bag 12, the control device 40 may leave the first predetermined amount at the first predetermined amount without replacing it in step S12, and may replace the second predetermined amount in step S14 with a fourth predetermined amount.

[0152] Second Embodiment Next, a pulmonary function measuring device 1 according to a second embodiment of the present disclosure will be described, focusing mainly on the differences from the pulmonary function measuring device 1 according to the first embodiment described above.

[0153] 9 is a diagram showing the configuration of a pulmonary function measuring device 1 according to a second embodiment of the present disclosure. The pulmonary function measuring device 1 of the second embodiment does not include the first valve V1, the second container 20, the movement amount detection sensor 30, or the three-way valve Vt.

[0154] In the pulmonary 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. Furthermore, in the pulmonary 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 pulmonary function measuring apparatus 1 of the second embodiment includes a flow rate sensor 170 disposed in the first connecting tube L1. The flow rate 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 rate sensor 170 detects the flow rate of gas released from the first space R1 to 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 result of the flow rate sensor 170 is transmitted to the control device 40.

[0157] When the subject's breath flows from the mouthpiece MP into the first space R1, the gas in the first space R1 is released to the atmosphere via the first connecting tube L1. When the subject's breath flows from the mouthpiece MP into the second bag 12, the second bag 12 expands, causing the gas in the first space R1 to be released to the atmosphere via the first connecting tube L1. In other words, the flow rate of the subject's breath flowing into the first space R1 and the flow rate of the subject's 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 the subject's exhaled breath flowing into the first space R1 and the amount of the subject's exhaled breath 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 through the first connecting tube L1. When the subject inhales test gas in the first bag 11 through the mouthpiece MP, the first bag 11 contracts, causing air to flow into the first space R1 through the first connecting tube L1. Furthermore, when the subject's exhaled breath in the second bag 12 is delivered to the CO sensor 52 and the He sensor 53 by the deliverer 51, the second bag 12 contracts, causing air to flow into the first space R1 through 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 inhaled by the subject in the first bag 11, and the flow rate of the subject's exhaled breath delivered from the second bag 12 by the deliverer 51 are detected by the flow sensor 170.

[0160] Furthermore, by integrating the detection results of the flow sensor 170 over time, 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 the subject's exhaled gas delivered from the second bag 12 by the delivery device 51.

[0161] Therefore, the control device 40 can generate the spirogram shown in Fig. 4 based on the detection results of the flow sensor 170, similar to the control device 40 of the first embodiment described above. Furthermore, by using the detection results of the flow sensor 170, the control device 40 can execute the flowcharts shown in Figs. 3, 5, and 6 and perform a DLco test, similar to the control device 40 of the first embodiment described above.

[0162] As described above, according to the second embodiment, the pulmonary function measuring device 1 includes: a first container 10 having a first space R1; an expandable second bag 12 that is disposed in the first space R1 and into which the exhaled breath of a subject who has inhaled a test gas during a pulmonary function test is injected; a first connecting tube L1 having a first end L1a connected to the first space R1 and a second end L1b open to the atmosphere; a flow sensor 170 disposed in the first connecting tube L1; a second connecting tube L2 having a first end L2a connected to the second bag 12 and a second end L2b open to the atmosphere; a CO sensor 52 and a He sensor 53 disposed in the second connecting tube L2 and detecting the concentrations of gases contained in the exhaled breath of the subject during the pulmonary function test; a sender 51 disposed in the second connecting tube L2 that sends the exhaled breath of the subject 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 the subject's exhaled breath sent to the CO sensor 52 and the He sensor 53 based on the detection result of the flow rate sensor 170.

[0163] According to this, when the breath of the subject in the second bag 12 is delivered by the delivery device 51 to the CO sensor 52 and the He sensor 53 via the second connecting tube L2 during a pulmonary function test, 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 breath of the subject delivered to the CO sensor 52 and the He sensor 53 based on the detection result of the flow rate sensor 170. The amount of the breath of the subject delivered to the CO sensor 52 and the He sensor 53 corresponds to the amount of the breath of the subject used in the pulmonary function test (analysis amount). In this way, the pulmonary function measuring device 1 can detect the amount of the breath of the subject used in the pulmonary function test. [Explanation of symbols]

[0164] 1. Pulmonary function measuring device 10 1st container 11 First Bag 12 Second Bag (Bag) 20 Second container 21 cylinders 22 Piston 23 Diaphragm 30 Movement detection sensor 40 Control device 51 Sending machine 52 CO sensor (concentration sensor) 53 He sensor (concentration sensor) 61 First Switch 62 Second Switch (Switch) 170 Flow Sensor L1 First connecting pipe L1a: First end of the first connecting pipe L1b Second end of the first connecting pipe L2 Second connecting pipe L2a First end of second connecting pipe L2b Second end of second connecting pipe L3 Third connecting pipe L3a Third connecting pipe section R1 First space R2 2nd space V1 First valve V2 Second valve Vt Three-way valve (open to atmosphere)

Claims

1. a first container having a first space; an expandable bag disposed in the first space and into which exhaled breath of a subject who has inhaled a test gas is injected during a pulmonary function test; 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 amount detection sensor that detects a movement amount of the piston relative to the cylinder; a first connecting pipe connecting a second space surrounded by the cylinder and the piston to the first space; a second connecting tube having a first end connected to the bag; a concentration sensor disposed in the second connecting tube for detecting a concentration of gas contained in the exhaled breath of the subject during the pulmonary function test; a sender disposed in the second connecting tube and configured to send the exhaled breath of the subject in the bag to the concentration sensor; a control device; the control device derives the amount of exhaled breath of the subject sent to the concentration sensor based on the amount of movement of the piston detected by the movement amount detection sensor. Pulmonary function measuring device.

2. the second connecting tube is disposed closer to a second end than the concentration sensor, and has an atmosphere opening portion that releases the exhaled breath of the subject to the atmosphere when the deliverer delivers the exhaled breath of the subject to the concentration sensor. The pulmonary function measuring device according to claim 1 .

3. a first valve disposed in the first connecting pipe for opening and closing the first connecting pipe; a second end of the second connecting pipe connected to the second space; the control device closes the first connecting tube using the first valve when the exhaled air of the subject in the bag is delivered to the concentration sensor by the delivery device; The pulmonary function measuring device according to claim 1 .

4. a third connecting tube connecting the bag to a mouthpiece into which the subject's exhaled breath is blown; a second valve disposed in the third connecting pipe and configured to open and close the third connecting pipe; The control device when the subject's breath is blown into the mouthpiece, the operation timing of the second valve is controlled based on the movement amount of the piston detected by the movement amount detection sensor so that the amount of the subject's breath injected into the bag becomes a predetermined amount; the third connecting tube is closed by the second valve, and the exhaled breath of the subject in the bag is sent to the concentration sensor by the sender; Multiplying the concentration of the gas detected by the concentration sensor by a first correction coefficient of the following formula (1): The pulmonary 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 of the third connecting pipe between the second valve and the bag.

5. the control device multiplies the concentration of the gas detected by the concentration sensor by a second correction coefficient of the following formula (2) instead of the first correction coefficient when a change in the amount of the exhaled gas of the subject delivered to the concentration sensor per unit time is equal to or less than a predetermined change when the exhaled gas of the subject in the bag is delivered to the concentration sensor by the deliverer; The pulmonary function measuring device according to claim 4. C2=(Q3+Q2) / Q3...(2) C2 is the second correction coefficient, and Q3 is the amount of the subject's exhaled breath delivered to the concentration sensor when the change per unit time in the amount of the subject's exhaled breath delivered to the concentration sensor becomes less than a predetermined change amount.

6. a third connecting tube connecting the bag to a mouthpiece into which the subject's exhaled breath is blown; a second valve disposed in the third connecting pipe and configured to open and close the third connecting pipe; The control device when the subject's breath is blown into the mouthpiece, the operation timing of the second valve is controlled based on the movement amount of the piston detected by the movement amount detection sensor so that the amount of the subject's breath injected into the bag becomes a predetermined amount; When the amount of the exhaled breath of the subject delivered to the concentration sensor is less than the predetermined amount, the operation timing of the second valve is adjusted so that the amount of the exhaled breath of the subject injected into the bag is increased. The pulmonary function measuring device according to claim 1 .

7. a first container having a first space; an expandable bag disposed in the first space and into which exhaled breath of a subject who has inhaled a test gas is injected during a pulmonary function test; a first connecting pipe having a first end connected to the first space and a second end open to the atmosphere; a flow rate sensor disposed in the first connecting pipe; a second connecting tube having a first end connected to the bag and a second end open to the atmosphere; a concentration sensor disposed in the second connecting tube for detecting a concentration of gas contained in the exhaled breath of the subject during the pulmonary function test; a sender disposed in the second connecting tube and configured to send the exhaled breath of the subject in the bag to the concentration sensor; a control device; the control device calculates the amount of exhaled breath of the subject sent to the concentration sensor based on the detection result of the flow rate sensor. Pulmonary function measuring device.

Images