JP2015134080A - Respiratory function test system and breathing passage for respiratory function test system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for testing a respiratory function (pressure flow rate characteristics) of a subject.SOLUTION: An air intake path 19b is narrowed to load air intake resistance by changing the posture of a plate-like member 19f of a flow passage resistance switcher 19e by rotation in the air intake path 19b of a respiratory organ 11 through which intake air of a subject passes, a flow sensor detects a flow rate of intake air of the subject passing through an air intake path 19b of the respiratory organ 11, a pulse wave sensor detects a pulse wave of the subject, and a respiratory function test apparatus tests a respiratory function by a pleural pressure signal estimated on the basis of an intake air signal from the flow sensor and a pulse wave signal from the pulse wave sensor.

Description

  The present invention relates to a technique for examining a subject's respiratory function such as lung compliance.

  In recent years, lung diseases such as pneumonia and COPD (chronic obstructive pulmonary disease) have been increasing all over the world. Lung compliance, which indicates the flexibility of the lung, is said to be a useful index for screening lung diseases and confirming therapeutic effects. Measurement of pulmonary compliance requires measurement of intrathoracic pressure. Measurement of esophageal pressure, which is a substitute for it, requires a balloon catheter or a catheter with a pressure transducer to be inserted into the esophagus, which is very painful for the patient and can be easily performed. is not.

  As a countermeasure, a blood pressure transducer for measuring blood pressure (open blood pressure) and an electrocardiogram electrode for measuring the heartbeat cycle are used, and an electrocardiogram waveform signal derived from the cardiac contraction obtained from the electrocardiogram electrode is used to measure the blood pressure. A technique for extracting a respiratory function signal indicating a respiratory function from a blood pressure waveform signal detected by a transducer has been proposed (see Patent Document 1).

  In addition, a technique for measuring the respiratory function of a subject from the flow rate of the subject's breath passing through the respiratory path has also been proposed (see Patent Document 2).

JP 2010-142594 A JP 2012-187292 A

  However, although the above-mentioned technique can reduce the burden of measuring the esophageal pressure, it is an invasive test or does not directly measure the flexibility of the lungs, so it accurately tests the respiratory function of the subject. There was a problem that could not be done.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a technique for examining the respiratory function (pressure flow characteristics) of a subject.

  A respiratory function test system according to claim 1 made to solve the above-mentioned problem is a respiratory function test system for testing a subject's respiratory function, the inspiratory path through which the subject's inspiration passes, A flow rate sensor for detecting the flow rate of the subject's inspiration passing through the inhalation path, a pulse wave sensor for detecting the pulse wave of the subject, a flow rate of the inhalation of the subject detected by the flow rate sensor, and the pulse wave A respiratory function inspection unit that examines the respiratory function of the subject based on the pulse wave of the subject detected by the sensor, and suppresses inspiration when the subject inhales in the inspiratory path A resistance load section for loading an intake resistance, which is a resistance to perform, is provided.

  According to the respiratory function inspection system of the present invention configured as described above, the respiratory function of the subject is examined based on the flow rate of the subject's inspiration and the pulse wave of the subject. Even if the esophageal pressure is not measured, the respiratory function (pressure flow characteristic) of the subject can be examined.

  In addition, this invention is realizable also as a respiratory path | route for the respiratory function test | inspection system which comprises the above-mentioned respiratory function test | inspection system.

It is explanatory drawing which shows the outline | summary of the respiratory function test | inspection system of this embodiment. It is explanatory drawing which shows the outline | summary of the respiratory function test | inspection system of this embodiment. It is explanatory drawing which shows the outline | summary of the flow-path resistance variable apparatus of this embodiment. It is explanatory drawing which shows the outline | summary of the flow-path resistance variable apparatus of this embodiment. It is explanatory drawing which shows the outline | summary of the flow-path resistance variable apparatus of this embodiment. It is explanatory drawing which shows the estimation result of the intrathoracic pressure by the pulse wave using the port pressure (intraoral pressure) of a pressure acquisition port. It is explanatory drawing which shows the outline | summary of the flow-path resistance variable apparatus of another embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
[1. Description of configuration of respiratory function test system 1]
The respiratory function test system 1 according to the present embodiment is based on the inspiratory amount data when the subject breathes and the intrathoracic pressure data obtained from the pulse wave of the subject. It is an inspection system for inspecting.

  Specifically, as shown in FIGS. 1 and 2, the respiratory function test system 1 includes a flow rate sensor (low pressure loss flow rate sensor) 3 that detects a gas flow rate (intake flow rate) during inhalation of a subject, A pulse wave sensor (volume pulse wave sensor) 5 for detecting the pulse wave of the examiner, an intake signal indicating the flow rate of the subject's inspiration detected by the flow rate sensor 3 and the pulse of the subject detected by the pulse wave sensor 5 A respiratory function testing device 7 as a respiratory function testing unit for testing the respiratory function of the subject based on a pulse wave signal indicating a wave, a display unit 9 for outputting a test result by the respiratory function testing device 7, and a respiratory path As a respiratory device 11.

[1.1. Description of the configuration of the flow sensor 3]
The flow sensor 3 detects the inspiratory flow rate of the subject passing through the inspiratory path 13 b of the respiratory device 11. As the flow rate sensor 3, for example, a well-known flow rate sensor that can detect a gas flow rate such as a differential pressure type, a hot wire type, or an ultrasonic type can be used. From the flow sensor 3, an electrical signal (intake amount signal) indicating the inspiratory flow rate is output to the respiratory function testing device 7.

[1.2. Explanation of Configuration of Pulse Wave Sensor 5]
The pulse wave sensor 5 is an optical sensor provided with a known light emitting element (LED) or light receiving element (PD). For example, the pulse wave sensor 5 irradiates light on the fingertip of the subject and uses the reflected light to make a pulse wave. (Volume pulse wave) can be detected. The pulse wave sensor 5 outputs a pulse wave signal indicating the state of the pulse wave to the respiratory function testing device 7.

[1.3. Description of the configuration of the respiratory function testing device 7]
The respiratory function inspection device 7 is an electronic control device centered on a known microcomputer, and based on the inspiration signal from the flow sensor 3 and the pulse wave signal from the pulse wave sensor 5, the respiratory function inspection and display unit 9 Control. The respiratory function testing device 7 functionally includes an inspiration signal acquisition unit 7a, a pulse wave signal acquisition unit 7b, an inspiration amount calculation unit 7c, an intrathoracic pressure estimation unit 7d, and a respiratory function detection unit 7e. I have. The intake signal acquisition unit 7a acquires (measures) an intake air amount signal indicating an intake air amount (that is, a gas flow rate) from the flow rate sensor 3 per unit time. The pulse wave signal acquisition unit 7b drives the pulse wave sensor 5 to acquire a pulse wave signal indicating the pulsation state of the blood vessel. The intake air amount calculation unit 7c calculates the intake air amount during the inspiration period of each breath based on the intake air amount signal. Specifically, the intake air amount is obtained by integrating the intake air flow rate obtained from the intake air amount signal. The intrathoracic pressure estimation unit 7d analyzes the pulse wave signal and estimates the intrathoracic pressure. The respiratory function detection unit 7e examines (determines) the respiratory function based on the data of the inspiratory amount calculated by the inspiratory amount calculating unit 7c and the intrathoracic pressure estimated by the intrathoracic pressure estimating unit 7d. The respiratory function detection unit 7e estimates the intrathoracic pressure due to the pulse wave using the port pressure (intraoral pressure) of the pressure acquisition port 21 described later. FIG. 6 is a graph showing the estimation result of the intrathoracic pressure by the pulse wave using the port pressure (intraoral pressure) of the pressure acquisition port 21.

[1.4. Description of configuration of display unit 9]
The display unit 9 is a device for notifying a respiratory function test result obtained by the respiratory function test device 7, and includes a display such as a liquid crystal display, a speaker, and the like.

[1.5. Description of Respirator 11 Configuration]
Next, the configuration of the respiratory apparatus 11 to which the present invention is applied will be described.
The respirator 11 is a device that allows the breath and inhalation of the subject to pass through in order to examine the breathing function of the subject. As shown in FIG. 3, the respirator body 13, the mouthpiece 15, and the filter 17. And a flow path resistance variable device 19 as a resistance load section.

The respiratory main body 13 is configured in a cylindrical shape so that the exhalation and inspiration of the subject can pass therethrough. Note that the flow rate sensor 3 described above is attached to the respiratory body 13.
The mouthpiece 15 is a device that is used by the subject to inhale exhaled air into the respiratory body 13 or inhale inhaled air, and is attached to the front end side of the respiratory body 13 via the filter 17. .

  The filter 17 is a device that cleans the exhalation and inspiration of the subject that passes through the respirator 11, and is attached between the respirator body 13 and the mouthpiece 15. A pressure acquisition port 21 for measuring the intrathoracic pressure and intraoral pressure of the subject is provided at the front end of the filter 17 and is connected to the respiratory function testing device 7. This pressure acquisition port 21 measures the subject's intrathoracic pressure when the intake path 19b of the flow path resistance variable device 19 is narrowed by the flow path resistance switch 19e, while the intake path 19b is measured by the flow path resistance switch. It can be used for measuring the intraoral pressure of the subject when spread by 19e. In addition, the location where the pressure acquisition port 21 is provided in the respirator 11 is downstream of the location where the flow sensor 3 is attached to the respirator 11 (location where the inspiratory flow rate of the subject is detected). Yes.

The flow path resistance variable device 19 is a device that loads an inspiratory resistance, which is a resistance for suppressing inspiration when the subject inhales, and is attached to the rear end side of the respiratory body 13.
In addition, the flow resistance variable device 19 is formed with an exhalation path 19a through which the subject's exhalation passes and an inhalation path 19b through which the inhalation of the subject passes, and the front end portion of the exhalation path 19a and the inhalation path The front end portion of 19b is opened, and the front end portion of the exhalation path 19a and the front end portion of the inhalation path 19b are joined together in a substantially Y shape, and when attached to the respirator body 13, the respirator body 13 It is connected to the rear end. A check valve 19c is provided in the exhalation path 19a, and the check valve 19c allows the subject's exhalation to pass through the exhalation path 19a from the front end side (upstream side) to the rear end side (downstream side). Gas flow in the opposite direction is prevented while allowing flow toward the. In addition, in the intake passage 19b, a check valve 19d is provided on the front end side, and a flow path resistance switch 19e as a resistance load portion is provided on the rear end side. In the intake passage 19b, the check valve 19d allows the subject's intake air or the like to flow in the intake passage 19b from the rear end side (upstream side) to the front end side (downstream side). Gas flow in the direction is blocked. Further, the flow path resistance switch 19e is configured such that the plate-like member 19f can rotate around a shaft 19g orthogonal to the longitudinal direction of the intake passage 19b, and the plate is rotated by rotation in the intake passage 19b. By changing the posture of the member 19f, the intake passage 19b is narrowed to load the intake resistance. The plate-like member 19f may be rotated manually such as by rotating the shaft 19g, or the plate-like member 19f is provided in either the narrowed state or the widened state of the intake passage 19b. In addition, the plate-like member 19f may be rotated using a gas flow.

[2. Explanation of respiratory function test using respiratory function test system 1]
Next, the respiratory function test using the respiratory function test system 1 will be described.
(1) Calibration of Respiratory Function Test System 1 To calibrate the respiratory function test system 1, as shown in FIG. 4, the intake path 19b of the variable flow resistance device 19 is narrowed by a flow resistance switch 19e ( 1st resistance load state), when the subject breathes, inhalation resistance (resistance of 15 cmH ₂ O or more) having a value sufficiently larger than the airway resistance, which is resistance to suppress the breathing in the airway, is applied to the oral cavity Respiratory fluctuations appearing in the pulse wave when internal pressure and intrathoracic pressure (≒ esophageal pressure) drop are measured. In the exhalation path 19a, the exhalation resistance, which is a resistance for suppressing exhalation when the subject exhales, is kept smaller than the airway resistance (resistance of 3 cmH ₂ O or less). At this time, since the respiratory volume is small, the airway resistance becomes almost zero, and the intraoral pressure≈the intrathoracic pressure. Then, a conversion coefficient C is obtained from the ratio between the intraoral pressure and the respiratory wave fluctuation amount.

(2) Measurement of estimated intrathoracic pressure P and respiratory flow V (PV measurement)
Next, when measuring the estimated intrathoracic pressure P and respiratory flow rate V of the subject, as shown in FIG. 5, the inspiratory path 19b of the flow path resistance variable device 19 is widened by the flow path resistance switch 19e. (Second resistance load state), switching to a state where an inspiratory resistance (resistance of 3 cmH ₂ O or less, in this embodiment, almost zero (open)) smaller than the airway resistance is loaded, and the respiratory flow rate when breathing V and the pulse wave are measured, and an estimated intrathoracic pressure P is obtained using the conversion coefficient C obtained at the time of calibration of the respiratory function test system 1 of (1) (see the following formula).

Estimated intrathoracic pressure P = Respiration fluctuation amount of pulse wave × Conversion coefficient C
In the exhalation path 19a, as in the calibration of the respiratory function test system 1 in (1) above, the exhalation resistance, which is a resistance for suppressing exhalation when the subject exhales, is kept smaller than the airway resistance. Sagging (resistance of 3 cmH ₂ O or less).

(3) Calculation of lung compliance etc. A PV diagram is drawn from the estimated intrathoracic pressure P and respiratory flow V obtained in (2) above, and the slope of V / P (lung compliance), area, etc. are obtained.

(4) Evaluation By changing the respiratory volume and respiratory cycle to obtain V / P, etc., the respiratory frequency, characteristics for each respiratory flow (lung compliance; lung elastic modulus), workload, etc. are evaluated.

[3. Effects of the embodiment]
As described above, according to the respiratory function testing system 1 of the present embodiment, the posture of the plate-like member 19f of the flow path resistance switch 19e is rotated in the inspiratory path 19b of the respirator 11 through which the subject's inspiration passes. Is changed so that the inspiratory path 19b is narrowed to load the inspiratory resistance, and the flow rate sensor 3 detects the inspiratory flow rate of the subject passing through the inspiratory path 13b of the respirator 11, and the pulse wave sensor 5 detects the pulse wave of the subject, and the respiratory function test device 7 tests the respiratory function based on the inspiratory pressure signal from the flow sensor 3 and the intrathoracic pressure signal estimated based on the pulse wave signal from the pulse wave sensor 5. Therefore, the respiratory function of the subject can be examined without measuring the esophageal pressure as in the prior art.

[4. Other Embodiments]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, It is possible to implement in the following various aspects.

  (1) In the above embodiment, the variable flow resistance device 19 has a substantially Y shape in which the front end of the exhalation path 19a and the front end of the inhalation path 19b merge, and is attached to the respiratory body 13 However, the present invention is not limited to this, and as illustrated in FIG. 7, the lower end of the exhalation path 119a and the front end of the inhalation path 119b merge. It is good also as the flow-path-resistance variable apparatus 119 comprised so that it might be connected to the rear-end part of the respiratory organ main body 13, when it is a letter shape and attached to the respiratory main body 13. In the variable flow resistance device 119 of the present embodiment, a check valve 119c is provided in the exhalation path 119a. By this check valve 119c, the exhalation of the subject passes through the exhalation path 119a on the lower end side ( While it is allowed to flow from the upstream side toward the upper end side (downstream side), gas flow in the opposite direction is prevented. Further, a flow path resistance switch 119e having the same configuration as the above-described flow path resistance switch 19e is provided in the intake path 119b. The flow path resistance switch 119e is configured such that the plate-like member 119f can rotate about an axis 119g orthogonal to the longitudinal direction of the intake passage 119b, and the plate-like member 119f is rotated in the intake passage 119b by rotation. By changing the posture of the member 119f, the intake path 119b is narrowed to load the intake resistance. The plate-like member 119f may be rotated manually such as by rotating the shaft 119g, or the plate-like member 119f is provided in either the narrowed state or the widened state of the intake passage 119b. The plate-like member 119f may be rotated using a gas flow.

  (2) In the above embodiment, in the intake passage 19b, the posture of the plate member 19f of the flow path resistance switch 19e is changed by rotation to narrow the intake passage 19b and load the intake resistance. However, the present invention is not limited to this. For example, the intake passage 19b may be narrowed by narrowing the intake passage 19b so that the intake passage 19b is loaded with intake resistance, or a valve body that opens and closes the intake passage 19b is provided. Then, the intake path 19b may be narrowed by driving the valve body so that the intake path 19b is loaded with an intake resistance.

DESCRIPTION OF SYMBOLS 1 ... Respiratory function test | inspection system, 3 ... Flow rate sensor, 5 ... Pulse wave sensor, 7 ... Respiratory function test apparatus, 7a ... Inspiration signal acquisition part, 7b ... Pulse wave signal acquisition part, 7c ... Inhalation amount calculation part, 7d ... Chest cavity Internal pressure estimation unit, 7e ... Respiratory function detection unit, 9 ... Display unit, 11 ... Respirator, 13 ... Respiratory body, 15 ... Mouthpiece, 17 ... Filter, 19 ... Variable flow resistance device, 19a ... Exhalation path, 19b ... Intake path, 19c, 19d ... Check valve, 19e ... Flow resistance switch, 19f ... Plate member, 19g ... Shaft, 21 ... Pressure acquisition port, 119 ... Flow resistance variable device, 119a ... Exhalation path, 119b ... Intake path, 119c ... check valve, 119e ... flow path resistance switch, 119f ... plate member, 119g ... shaft.

Claims (10)

A respiratory function test system (1) for testing the respiratory function of a subject,
A breathing path (11) having an expiration path (19a) through which the subject's exhalation passes and an inspiration path (19b) through which the subject's inspiration passes;
A flow rate sensor (3) for detecting a flow rate of a subject's intake air passing through the intake path (19b);
A pulse wave sensor (5) for detecting the pulse wave of the subject;
Respiratory function testing unit for examining the respiratory function of the subject based on the inspiratory flow rate of the subject detected by the flow sensor (3) and the pulse wave of the subject detected by the pulse wave sensor (5) (7)
The respiratory function test system characterized in that the intake path (19b) is provided with a resistance load section (19e) for loading an intake resistance, which is a resistance for suppressing intake when the subject inhales. (1). In the respiratory function test system (1) according to claim 1,
The respiratory function test system (1), wherein the resistance load section (19e) loads the intake resistance on the intake path (19b) by narrowing the intake path (19b). In the respiratory function test system (1) according to claim 2,
The resistance load section (19e) narrows the intake path (19b) by narrowing the intake path (19b), and loads the intake resistance on the intake path (19b). (1). In the respiratory function test system (1) according to claim 2,
The resistance load portion (19e) has a plate-like member (19f) whose posture can be changed in the intake passage (19b), and the intake passage is changed by changing the posture of the plate-like member (19f). Respiratory function test system (1), wherein (19b) is narrowed and the inspiratory resistance is loaded on the inspiratory path (19b). In the respiratory function test system (1) according to claim 2,
The resistance load section (19e) has a valve body (19d) that opens and closes the intake path (19b), and drives the valve body (19d) to narrow the intake path (19b), thereby reducing the intake path. A respiratory function test system (1), wherein the inhalation resistance is loaded on (19b). In the respiratory function test system (1) according to any one of claims 1 to 5,
In the inspiratory path (19b), the resistance load section (19e) reduces the inspiratory resistance having a value sufficiently larger than the airway resistance, which is a resistance for suppressing breathing in the airway when the subject breathes. It is possible to switch between a first resistance load state to load and a second resistance load state to load the intake resistance having a value smaller than the airway resistance,
In the exhalation path (19a), the respiratory function test system (1) is characterized in that an exhalation resistance that is a resistance for suppressing exhalation when the subject exhales is kept smaller than the airway resistance. . In the respiratory function test system (1) according to claim 6,
In the intake path (19b), when the resistance load portion (19e) is in the first resistance load state, a load of 15 cmH ₂ O or more is loaded as the intake resistance, while in the second resistance load state. When there is a load of 3 cmH ₂ O or less as the intake resistance,
In the exhalation path (19a), a respiratory function test system (1), wherein a resistance of 3 cmH ₂ O or less is loaded as the exhalation resistance. In the respiratory function test system (1) according to claim 6 or 7,
The inhalation path (19b) is provided with a pressure acquisition port (21) for measuring the intrathoracic pressure and intraoral pressure of the subject, and the pressure acquisition port (21) is connected to the resistance load section (19e). ) Can be used to measure the intrathoracic pressure when in the first resistance load state, and can be used to measure the intraoral pressure when the resistance load portion is in the second resistance load state. Respiratory function test system (1). In the respiratory function test system (1) according to claim 8,
The pressure acquisition port (21) is provided on the downstream side of a place where the flow rate sensor (3) in the intake path (19b) detects the intake flow rate of the subject. System (1).   A respiratory path (11) for a respiratory function test system that constitutes the respiratory function test system (1) according to any one of claims 1 to 9.

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