JPH0131898B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulmonary function testing device, and particularly relates to a pulmonary function testing device that measures closing volume (hereinafter referred to as CV), functional residual capacity (hereinafter referred to as FCR), lung diffusing capacity (hereinafter referred to as _DLCO ), etc. An object of the present invention is to obtain a pulmonary function testing device that enables sequential measurements using the same device.

Measurement of CV is useful for early detection of small airway lesions caused by smoking, etc.

CV abnormalities are accompanied by ventilation-perfusion inequalities, causing hypoxemia and widening of A-aDO ₂ . There is a resident gas method for measuring CV. The N ₂ washout curve is calculated by measuring the change in the N ₂ concentration in the exhaled breath with an N ₂ analyzer when 100% O ₂ is inhaled once followed by a deep exhalation, followed by a slow exhalation. Have the relationship recorded.

CV evaluation is performed using CV/VC%, etc. as an index (VC: vital capacity). When the volume is plotted on the horizontal axis and N ₂ % is plotted on the vertical axis using the above method, the N ₂ concentration curve initially shows 0% N ₂ concentration due to the gas from the dead space replaced by 100% O ₂ , and then As the exhaled volume increases, the _N2 concentration rapidly increases due to the mixing of alveolar air gas. After that, only alveolar air is exhaled, resulting in a flat _N2 curve. However, small waves can be seen with the heartbeat. Furthermore, a closed circuit method using helium is used for FRC measurements. This involves putting gas containing H _e into a spirometer, measuring its concentration, and then connecting the patient to rest ventilation, which reduces the H _e concentration and keeps the H _e gas concentration at a constant value. In this method, the FRC is obtained by reading the value when , and calculating the initial _He concentration and the measured value. In addition, the measurement of D _LCO is used to check whether gas exchange between alveolar gas and pulmonary capillaries is disrupted during the diffusion process even if ventilation function and pulmonary circulation are normal. According to the breath-holding D _LCO measurement method, a spirometer, a J-valve, a rubber tube connecting these, one or two sample bags, forceps to clamp the ends of the bags, a mouthpiece, and an infrared ray for gas measurement are used. Carbon oxide analyzer, katharometer for H _e analysis, and the mixed gas used is 0.3% CO,
10% H _e , 20% O ₂ , and 70% N ₂ are used.

However, the measurements of CV, FRC, and D _LCO have to be carried out separately in each device, which is not only inconvenient, but also requires each device to be equipped with a separate flow sensor, which is wasteful in the configuration of the device.

The present invention was made in view of the above-mentioned drawbacks.CV,
The object of the present invention is to obtain a pulmonary function testing device that can sequentially measure FRC and D _LCO using the same device.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit block diagram of the present invention, and FIG.
The figure is a perspective view of a four-port valve used in the present invention, and FIG. 3 is a partially assembled exploded view of FIG. 2. In the figure, 1 is a subject and 2 is a pulmonary function testing device. The pulmonary function testing device 2 includes a mouthpiece 3 that is held in the mouth by the subject 1, a flow sensor 4 that is connected downstream to the mouthpiece 3, and extracts the flow rate of respiratory air as a differential pressure.
A needle valve 6 that is opened into an air conduit 5 connected downstream to the flow sensor 4 and adjusts the amount of gas to be sampled; an N ₂ detector 8 connected to the needle valve 6 and provided in the middle of the signal line 7; A four-port valve 9 is provided in the air conduit 5 spaced apart from the valve 6.

The four-port valve 9 is shown in the perspective view of FIG.
As shown in the figure, a second communication hole 92A, a third communication hole 92B, and a fourth communication hole 92C (the first communication hole 106 will be described later) are formed in the peripheral wall of the cylindrical valve housing 91. The one shown has a second communication hole 92B with a slightly larger diameter in the center of the lower part of the valve housing 91, and three second and fourth communication holes with a slightly smaller diameter on both sides of the lower part, spaced apart by 60 degrees. has been done. Further, one side of the valve housing 91 is open, and the other side is closed by an end plate 93 fixed thereto. Further, fasteners 94 are attached to both sides of the opening on one side of the valve housing 91. An annular seal body 95 having a diameter-reducing force is fitted and accommodated in the valve housing 91, and a plurality of seal bodies 95 are fitted in the valve housing 91, and a plurality of seal bodies 95 are formed in the valve housing 91, each corresponding to each of the communication holes 92A, 92B, and 92C. Flow holes 96A, 96B, and 96C are formed. In addition, the mounting hole 97 of the valve housing 91
A positioning screw 98 is inserted into the seal body 95 from above.

A cylindrical valve body 99 is rotatably fitted into the seal body 95 of the valve housing 91.
At least one valve hole 100 and a throttle valve hole 101 are formed in the peripheral wall of the valve 9 . The reason why the throttle valve hole 101 is formed to have a slightly small diameter is to adjust the flow of exhaled and inhaled air to be constant when measuring CV. Further, one side of the valve body 99 is open, and the other side is closed with an end plate 102 provided therein, and a shaft protruding through the end plate 93 of the valve housing 91 is provided at the center outer side of the end plate 102. A portion 103 is provided in a protruding manner, and a groove 104 is formed at the end of this shaft portion 103 .

A circular lid 105 is attached to one open end surface of the valve housing 91, and a communication hole 106 is formed in the center of the lid 105. Also, lid body 1
05 on both sides of the valve housing 91.
A locking tool 107 that removably engages with the valve housing 91 and the lid body 105 is attached.
4, 107 by engaging the valve housing 9
One side opening surface of 1 is sealed openably and closably by a lid body 105.

In addition, nipples 10 are installed in the second communication hole 92A and the fourth communication hole 92C on both sides of the lower part of the valve housing 91.
8A and 108B are attached by screwing or the like, and an auxiliary valve 109 is connected to a third communication hole 92B at the center of the lower part of the valve housing 91. The auxiliary valve 109 has a communication section 111 connected to the valve housing 91 in the upper part of the main body 110, and communication valve parts 112 and 113 in the lower part and one side of the main body 110. A check valve is installed and fixed in the lower communication valve section 112 using a valve fixture (not shown). Further, a spring receiver, a valve spring, a valve receiver, and a check valve are assembled and fixed in the communication valve portion 113 on one side by means of a valve fixture. Reference numeral 114 denotes a drive device, which has a pulse motor 115, a reducer 116 is integrally coupled to this motor 114, and a drive shaft (not shown) protrudes from the end face of this reducer 116. The groove 1 of the shaft portion 103 of the valve body 99 is
A connecting pin (not shown) that is detachably connected to 04
is attached to transmit the rotational force of the pulse motor 115 to the valve body 99. 117 is a printed circuit board for a position sensor, which is arranged against the end surface of the reducer 116;
A plurality of photoelectric position sensors (not shown) are arranged on the outer surface of this printed circuit board 93, and a shaft notch (a notch for passing the drive shaft of the motor)
have.

For this reason, the four-port valve 9 has a valve hole 100 with a slightly larger diameter and a throttle valve hole 101 with a smaller diameter in the valve body 99. The second communication hole 92A, the third communication hole 92B, and the fourth communication hole provided in the
Open or close the communication hole 92C. Therefore, when measuring FRC, D _LCO , the valve hole 100
Use. First communication hole 10 of four-port valve 9
An air conduit 5 is connected to the 6 side. Also, nipple 1
08B and the communication valve section 112 are left open to the atmosphere. A sample bag (10, which will be described later) is connected to the nipple 108A, and one end of the bellows tube 13 is connected to the communication valve section 113. The other end of the bellows tube 13 is connected to one end of a pipe 15 via a demand valve 14. A flushing solenoid 16 is connected to the demand valve 14. The main body 110 of the auxiliary valve 109 and the communication portion 111 constitute an air conduit 11.
17 is a box. An O ₂ gas cylinder 21 and a mixed gas cylinder (H _e gas,
A type with a built-in mixed gas of CO gas, O ₂ gas, and N ₂ gas) 22 is provided. Inside the casing 17 is a shutoff valve 24 that disconnects between the pipe 23 connected to the mounting plug 18 and the subsequent pipe 25, and a shutoff valve 24 that connects the pipe 27 connected to the mounting plug 19 and the subsequent pipe 29. A cutoff valve 28 that is turned on and off, and a switching valve 26 that selects either the pipe 25 or the pipe 29 are connected in sequence. A pipe 30 is connected to the switching valve 26 and connected to a switching valve 32 via a pressure regulator 31 in the middle. The switching valve 32 has one end connected to the other end of the pipe 15, the other end connected to the pipe 33, and an intermediate speed controller 34.
It is connected to the switching valve 35 via. Switching valve 3
5 is connected to a switching valve 37, an H _e analyzer 38, and a CO analyzer 39 via a pipe 36, respectively. Further, the output sides of the H _e analyzer 38 and the CO analyzer 39 are led to an arithmetic circuit 40 having a built-in storage device. One side of the switching valve 37 has an open port, and the other side is connected to the sample bag 10 connected to a pipe 42 via a T-shaped pipe fitting 41, and the other side of the switching valve 37 is connected to a pipe 43. It has 44. The switching valve 44 connects and disconnects the pipe 43 and the exhaust pump 45. It has an N ₂ analyzer 46 connected downstream to the N ₂ detector 8, and a vacuum pump 48 connected downstream to a tube 47 branched from the N ₂ detector 8. 50 is a signal processing circuit consisting of a multiplier 51, an integrator 52, an adder 53, and an arithmetic unit 54;
This is to perform calculation processing on the measurement results of FRC and _DLCO , and the calculation processing may be performed using a computer. The multiplier 51 has one input as an electrical signal corresponding to the N ₂ concentration of the N ₂ analyzer 46,
The differential pressure output from the flow sensor 4 is supplied as an electrical signal to the other input via a line 49,
Multiply these values. An integrator 52 is connected to the output side of the multiplier 51, an adder 53 is connected to the output side of the integrator 52, and an arithmetic unit 54 is provided to the output side of the adder 53. In this embodiment, the mouthpiece 3 is the respiratory air conducting means, the air conduit 5 is the first air conduit, the O ₂ gas cylinder 21 is the O ₂ gas supply source, and the mixed gas cylinder 22 is the mixed gas supply source. , mounting plugs 18, 19, hose 21, pipes 23, 27, shutoff valves 24, 28, pipe 2
5, 29, the switching valve 26, the pipe 30, the pressure regulator 31, and the switching valve 32 constitute a gas switching means, the air conduit 11, the bellows tube 13, and the pipe 15 constitute a second air conduit, and the demand valve 14 The flush solenoid 16 constitutes a gas intermittent means, and the arithmetic circuit 40 and the signal processing circuit 50 constitute a signal processing means.

Next, the operation of the present invention will be explained.

<1> When measuring CV The valve body 99 of the four-port valve 9 is initially connected to the valve hole 1.
00, the pulse motor 11 is placed in the second circulation hole 92A to breathe the atmosphere.
5 and control it (hereinafter this state will be referred to as
(referred to as LO state).

Since CV measurement uses the resident gas method using 100% O ₂ inhalation, it is first necessary to clean the lung function system with O ₂ . Therefore, the valve body 99
The pulse motor 115 is driven to align the valve hole 100 with the third flow hole 92B (hereinafter, this state will be referred to as the L1 state). Flushing with O ₂ gas is performed by turning on the solenoid 16 to open the demand valve 14 and guiding the gas pressure of the O ₂ gas cylinder to the four ports 9 and the flow sensor 4. O ₂ gas is shut off valve 2
4, pipe 25, switching valve 24, pipe 30, pressure regulator 31, switching valve 32, pipe 15
It is led to the demand valve 14 via the demand valve 14, and then the bellows pipe 13, the air conduit pipe 11, the communication valve part 113 of the four-port valve 9, the third communication hole 92B, the valve hole 100, and the first communication hole. It is led to the air conduit 5 via 106. Further, the flow sensor 4 and mouthpiece 3 are also flashed at the same time.

Next, the O level of the flow sensor 4 is adjusted.

Next, the four-port valve 9 is set to the L0 state again, and the subject 1 puts the mouthpiece 3 in his mouth and performs rest ventilation.

Subject 1 continues to perform resting ventilation and then performs maximum inhalation and then maximum exhalation to complete the measurement 1 state.

Next, the throttle valve 1 of the valve body 99 of the four-port valve 9
01 to the third flow hole 92B side (hereinafter, this state is referred to as the S1 state), the subject sequentially performs maximum inhalation → maximum exhalation in a constant flow. At this time, the exhalation gas is from the throttle valve 1.
01 to the communication valve part 1 via the third communication hole 92B.
Open valve 1 provided in air conduit 11 guided to 12
2 is released to the outside. At this time, the N ₂ detector 8 detects the N ₂ gas component in the exhaled gas.
Analyze with _N2 analyzer 46. Thus,
The N ₂ concentration curve corresponding to the volume can be determined.
The calculation processing circuit 50 calculates the CV from this curve.
Perform calculations such as CV/VC%.

<2> When measuring FRC The measurement method is to wash out the N ₂ in the lungs with oxygen ventilation, and then calculate the FRC from the amount released.

Initially, the four-port valve 9 is opened to the atmosphere in the L0 state.

Next, it is necessary to flush the equipment system with O ₂ gas. To do this, first, the four-port valve 9 is set to the _L1 state, and the demand valve 14 is opened. As a result, the O ₂ in the O ₂ gas cylinder 21
For gas, prepare as in the case of CV measurement: cutoff valve 24, pipe 25, switching valve 26, pipe 3.
0, pressure regulator 31, switching valve 32, pipe 15, demand valve 14, bellows pipe 13,
It is guided to the air conduit 11, four-port valve 9, air conduit 5, flow sensor 4, and mouthpiece 3, and cleans these parts.

After that, the four-port valve 9 is returned to the L0 state. Also, adjust the O level of the flow sensor.

Subject 1 holds the mouthpiece 3 in his mouth and performs rest ventilation.

Next, in the state of measurement 1, the four port valve 9 is set to L1.
In this state, O ₂ gas from the O ₂ gas cylinder 21 is guided to the demand valve 14 via the switching valves 24 and 26, the pressure regulator 31, and the switching valve 32, and is inhaled into the lungs of the subject 1. Inhalation of this O ₂ gas is performed by performing quiet ventilation for 7 minutes. Thus, it can be recognized that as the number of respirations increases, the N ₂ concentration decreases and eventually reaches a value of 2% or less.

In the next measurement 2 state, the subject performs maximum exhalation → maximum inhalation. At this time, the method of calculating FRC from the N ₂ discharge amount obtained by completely flushing out the N ₂ in the lungs with pure oxygen is: The N ₂ discharge amount (VN ₂ ) is VN ₂ = FRC (F ₁ − F ₂ ) = It is expressed as Σ(∫FN ₂・Vdt).

Here, F ₁ : Intrapulmonary N ₂ concentration before washing out (assumed to be 81%) F ₂ : Intrapulmonary N ₂ concentration at the end of washing out. Therefore, FRC=VEΣ(∫FN ₂・Vdt)/F ₁ −F _2In reality, N ₂ is discharged from the body into the lungs during N ₂ flushing, so this value (VN ₂ b) was lowered according to Cournand et al. Corrected by the formula.

VN ₂ b = (BSA x 96.5) + 35 (ml) <3> D When measuring _LCO In the breath-holding method, the mixed gas used is 0.3% CO, 10% H _e , 20% O ₂ , 70% I'm using _N2 .

Leave the four-port valve 9 in the L0 state.

Next, in this state, switch the switching valve 37 to Air.
The H _e analyzer 38 and the CO analyzer 39 suck in air and check the O level of each analyzer. Next, flashing with a mixed gas is performed.
To do this, first set the four-port valve 9 to the _L1 state, switch the cutoff valve 28 so that the pipes 27 and 29 are connected, and switch the switching valve 26 so that the pipes 29 and 30 are connected. After switching the switching valve 32 so that the pipe 30 and the pipe 15 are connected, the demand valve 14 is opened. At this time, the mixed gas supplied from the mixed gas cylinder 22 is
Pipe 29, switching valve 26, pipe 30, pressure regulator 31, switching valve 32, pipe 15, demand valve 14, bellows pipe 13, air conduit 1
1, the four-port valve 9, the air conduit 5, the flow sensor 4, and the mouthpiece 3 to clean them.

Next, when the switching valves 32, 35, and 37 are switched to drive the exhaust pump 45, the mixed gas in the mixed gas cylinder 22 is transferred to the pipe 27, the switching valves 28, 26, the pressure regulator 31, and the switching valve 3.
2, 35, pipe 36, switching valve 37, pipe 4
It is pushed out after 3. At this time, the H _e analyzer 38 and the CO analyzer 39 suck the mixed gas from the pipe 36 and adjust the gain.

Next, by switching the switching valve 37 to the atmosphere side, the inside of the sample bag 10 is evacuated by operation of the exhaust pump 45. In this state, the four-port valve 9 is switched to the L0 state again.

Next, the subject 1 puts the mouthpiece 3 in his mouth and performs rest ventilation.

In the measurement 1 condition, rest ventilation is continued and finally maximum exhalation is performed.

Next, in the state of measurement 2, turn the four-port valve 9 to L1.
Mixed gas cylinder 2 with a signal to switch to the state
Inhale the mixed gas in 2 all at once to the maximum intake level. The mixed gas is guided into the lungs of the subject 1 via the switching valves 28, 26, the pressure regulator 31, the switching valve 32, the demand valve 14, and the flow sensor 4. And from the beginning of inspiration at that position
Hold your breath for 10 seconds. At this time, in the mixed gas
As CO is absorbed from the alveoli, the CO concentration decreases.

Then, on cue, the maximum number of calls is made rapidly. At this time, discard 750 ml of the first exhalation to wash away the dead space.

The four-port valve 9 is switched to the sample bag 10 side in order to collect the remaining exhaled gas as alveolar air at the final point of respiratory arrest. This connects the valve body 99 in the four-port valve 9 to the pulse motor 11.
5, the valve hole 100 is positioned on the fourth communication hole 92C side, and the L2 state is completed.
In this way, the sample bag 10 is collected via the nipple 108A. When a small amount of gas is introduced into the sample bag 10, the four-port valve 9 is switched to the L1 state.

In this way, the gas concentration when the gain was adjusted as described above and the gas concentration in the collected sample bag 10 are determined, and this is expressed by the formula D _LCO = V _A × 60/(P _B −47) tIn [Fl _CO /FAtCO ×F _A tH _e /FlH _e ] Where, V _A : Alveolar volume (STPD, measured in advance) P _B : Atmospheric pressure t : Breath-holding time (seconds) I _o : Natural logarithm 2.303× log Fl _cp , Fl _He : CO and
_He concentration F _Atcp , F _AtHe : D _LCO can be obtained by substituting the CO and _He concentrations in the gas exhaled after breath-holding and processing them in the arithmetic circuit 40.

As described above, the present invention is extremely convenient because it allows measurement of CV, FRC, and D _LCO to be sequentially switched using a four-port valve.

In addition, these electromagnetic valves, demand valves,
It goes without saying that control of a four-port valve, etc. can be easily performed by using a computer and performing software processing using a program.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the pulmonary function measuring device of the present invention. FIG. 2 is a perspective view of a four-port valve used in the present invention. Figure 3 is a partial assembly diagram of Figure 2. 3...Mouthpiece, 4...Flow sensor, 6...Needle valve, 9...Four port valve, 10...Sample bag, 106...First circulation hole, 38...H _e
Analyzer, 39... CO analyzer, 46... N ₂ analyzer, 50... Signal processing circuit, 92A... Second communication hole, 92B... Third communication hole, 14... Demand valve, 92C... Fourth communication hole.

Claims (1)

[Scope of Claims] 1. A respiratory air conduit means for guiding the respiratory air of a subject; a first air conduit tube connected at one end to the respiratory air conduit means; It has a flow sensor that detects the flow rate of gas in the first air conduit, a valve body, and four communication holes, and is configured to connect the first communication hole to any of the second to fourth communication holes. a four-port valve in which the valve body is switched, the first communication hole is connected to the other end of the first air conduit, and the second communication hole is in communication with the atmosphere; and an O ₂ gas supply source. , a mixed gas supply source that supplies a mixed gas consisting of He, CO, O ₂ and N ₂ gas, and a mixed gas supply source that is connected to the O ₂ gas supply source and the _mixed gas supply source, and that a gas switching means for selecting and supplying either one; a flow path for guiding the gas supplied from the gas switching means to the third communication hole of the four-port valve;
a second air conduit having an opening provided in the middle of the flow path and communicating with the atmosphere, and a valve that prevents gas from flowing from the atmosphere side to the flow path side through the opening; a gas intermittent means that is provided closer to the gas switching means than the opening of the conduit and that disconnects and disconnects the supply of gas to the third communication hole; and a gas intermittent means that is connected to the fourth communication hole of the four-port valve. a sample bag, a He analyzer and a CO analyzer connected to the sample bag, an N ₂ analyzer connected to the first air conduit, and signals output from the flow sensor, the N ₂ analyzer, and the CO analyzer. A pulmonary function testing device comprising a signal processing means for processing.