JPH04200478A - Exhalation valve apparatus for artificial respirator - Google Patents

Abstract

PURPOSE:To make the apparatus compact to satisfy responsiveness and accuracy by arranging a valve body which approaches to or separates from a valve seat member according to a displacement of a plate spring on one side of the spring held on a casing and an electromagnetic drive means to drive the plate spring on the other surface side thereof. CONSTITUTION:In an exhalation valve apparatus, exhalation from a valve seat member 34 is released into the atmospheric air at a release port 3 through an exhalation release space X during the opening of a valve, when a valve body 35 is separated from a valve seat 34a. As a plate spring 31 is displaced upward, the valve body 35 approaches the valve seat 34a to reduce the opening of the valve seat member 34. When a coil 45 is energized electrically, the coil 45 receives an electromagnetic drive force being displaced vertically and the vertical displacement position of the coil 45 corresponds to the vertical displacement positions of the plate spring 31 and a valve body 35. The larger the energization current for the coil 45, the larger the electromagnetic drive force. Thus, the opening of an exhalation circuit changes in a range of 0-100% and also, the valve body 35 is pivoted on the plate spring 31 thereby enabling accurate prevention of a leak of the inhaled air during the closing of the valve.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an exhalation valve device for a ventilator.

(Prior Art J5 and its Problems) In a ventilator, an inhalation circuit and an exhalation circuit are connected to a common circuit connected to a patient's lungs. From this inspiratory circuit, air with adjusted humidity and oxygen concentration is supplied to the common circuit, that is, the patient's lungs, while the air, after being converted into gas by the patient's lungs, is transferred from the common circuit to the exhalation circuit to the outside. is discharged to. The inhalation circuit is provided with an inhalation valve, while the exhalation circuit is provided with an exhalation valve.

1. The exhalation valve is used to control exhalation pressure and exhalation flow rate, and the most commonly used exhalation valve is of the so-called balloon type. That is,
The valve body of the exhalation valve itself is formed of a balloon, and the degree of opening of the exhalation circuit is adjusted by changing the degree of expansion of the balloon.

However, with such a balloon-type exhalation valve,
The responsiveness and accuracy are poor, and some kind of countermeasure is desired in this respect. For example, humans] - PEE in the respiratory tract
In the P device, it is desired to control the exhalation valve with good response and accuracy in order to maintain the PEEP pressure at a predetermined pressure, but it has not been possible to satisfy such demands.

On the other hand, as another type of exhalation valve, there is a so-called injection type. This is essentially the same thing as adjusting the opening of the exhalation circuit by injecting air into the exhalation circuit in the reverse flow direction and adjusting the injection pressure and amount. . However, even this injection type is still unsatisfactory in terms of its responsiveness and accuracy. In addition to this, as the air that is injected,
This consumes a large amount of intake gas that has been adjusted in the same way, so the reality is that it is used extremely infrequently.

In order to solve the above-mentioned problems, a valve body is used.

The exhalation valve door is a bar type exhalation valve that adjusts the opening of the exhalation circuit.
The present applicant has already proposed a type in which the valve body is directly driven by a reciprocating electromagnetic actuator (see Japanese Patent Laid-Open Publication No. 60-292965!] r1).

The present invention is based on the premise that the actuator is directly driven by a reciprocating electric M main actuator with a valve body (-7), so that it can be made compact as a whole while satisfying the response, l't, and accuracy points. The purpose is to provide an exhalation valve device for the Daio respiratory system.

(Structure, operation, and effect of the invention) In order to achieve the [-1 objective described in Mi+, the present invention has the following structure and 1 and 2 in terms of a dead tree. That is, the casing, the handling spring held in the gauging, and the 501) revision! a valve seat member provided on the casing so as to face one surface side of the leaf spring; It is constructed between a valve body that approaches and moves away from the valve seat member and the handling spring handling on the other side of the leaf spring, and drives the handling spring in the direction of its plate thickness by electromagnetic force. and an electromagnetic drive means for driving.

The discharge valve device having such a configuration can respond (and accurately change the amount of displacement of the leaf spring in the thickness direction) by controlling the electromagnetic drive means, that is, controlling the current (voltage). , since the amount of displacement of this handling spring is the relative position of the valve body with respect to the valve seat member, or the opening degree of the exhalation circuit,
The opening of the exhalation circuit will be changed responsively (and precisely as desired).

Moreover, the leaf spring, the valve seat member, the valve body, and the electromagnetic drive means can be effectively arranged with respect to the casing, thereby making it possible to make the whole casing compact.

In particular, since the electromagnetic drive +4-stage of the root spring is arranged on the opposite side of the valve body and valve seat +4, sandwiching the diagonal spring, this electric drive 1-stage reduces the amount of exhaled air passing through the valve seat member. It does not interfere with discharge.

The electromagnetic driving means uses a coil and a magnet, and the spring is driven in the direction of its plate thickness by the repulsive force between the coil and the magnet, which is caused by the electromagnetic main force generated when a current is applied to the coil. It is possible to use a device that has a displacement of In this case, the magnet is a permanent magnet, and in order to ensure its magnetic force as large as possible, the H1 stone is provided integrally with the casing, while a small coil resting on the eave roof is preferably provided integrally with the leaf spring side. "In addition, by supporting the valve body pivotably against the leaf spring, it is possible to ensure that the valve body is in close contact with the valve seat member and to obtain a reliable valve closing action. Become.

(Embodiments) Hereinafter, embodiments of the present invention will be described based on the attached drawings. In the following description, an example of the exhalation valve device according to the present invention will be explained first, and then a comparative example of the use of the exhalation valve device according to the present invention and a conventional device will be explained.

1 1 1 In Fig. 1, the C14 casing is made up of a bottomed cylindrical f casing C1, an annular middle casing C2, and a covered cylindrical ten casing C3, which are bolted or extended. It is constructed by integrating the parts by screwing them together.

''-A handling spring 31 is held in the casing C. More specifically, the leaf spring 31 is disk-shaped, and its outer peripheral edge is sandwiched between the middle casing C2 and the tenth casing C3 via a waterproof spring 32. The interior of the casing C is defined by such a leaf spring 31 into a lower exhalation release space X and a lower drive mechanism storage chamber Y. The exhaled air space X is constantly opened to the public through a release port 33 opened in the top wall of the casing C3.

■The top wall of the second casing C3 has a cylindrical valve seat member: 34
are screwed together and turned by a lock nut 34A. This valve seat member 34 extends in the 10F direction, its lower end opening is opened into the exhalation release space X, and its upper end is connected to the exhalation circuit using a joint or the like.

The lower end of the valve seat member 34 is a valve seat 34a, and a valve body 35 is attached to the leaf spring 31 facing the valve seat 34a. This valve body 35 is pivotally supported by the leaf spring 31. That is, the pivot bearing 36 having a spherical tip on the upper surface of the leaf spring 31 is identified, and the approximately conical recess 35u formed on the lower surface of the valve seal 35 is fitted into the spherical tip of the pivot bearing 36. has been done.

The valve body 35 and the pivot bearing 36 are coupled to each other by an annular locking band 37 formed so as to surround the pivot bearing 36 so as not to be separated from each other. This locking band is made of an elastic material such as rubber, and allows the valve body 35 to swing 360 degrees around the spherical tip of the pivot bearing 36.

In the drive mechanism storage chamber Y, a leaf spring 31 is attached to the valve body 3.
An electromagnetic drive mechanism is configured to drive 5 in the vertical direction. This electromagnetic drive mechanism 1-) will be detailed below.

First, an annular permanent magnet 4I is fixed to the lower casing CI. An annular inner magnetic pole member 42 is fixed to the soil surface of this permanent magnet.

The lower casing C1 is made of a ferromagnetic material such as iron, and the inner surface of the V end portion of the lower casing C1 is made of a ferromagnetic material such as iron.

An outer magnetic pole 43 is configured to face the inner magnetic pole member 42 .

On the other hand, a coil support member 44 is identified on the lower surface of the handling spring 31. This coil support member 44 has an annular coil holding part 44a extending with a predetermined gap between the inner magnetic pole member 42 and the outer magnetic pole 43, and a coil 45 is held in the coil holding part 44a. There is. In this way, the coil 45 and the magnetic poles 42, 43 constitute a linear motor.

A guide pin 46 is extended downward 2 and integrated into the coil holding member 44, and the guide pin 46 is connected to the inner H1 magnetic pole material 4.
2 and extends into the inner hole 41a of the permanent U1 stone 41 communicating therewith. Inner hole 4 of inner magnetic pole member 42
2 y, i A cylindrical guide member 47 with low sliding resistance, such as a deflon, is fixed to the inner surface, and the guide bottle 46 is smoothly guided by this guide member 47. In addition,
The diameter of the inner hole 41a of the permanent magnet 41 is much larger than the outer shape of the guide bin 46, and forms an escape space for the guide bin 46.

The inner holes 41a and 42a, the guide pin 46, the spherical tip of the pivot bearing 36, and the valve seat member 34 are located on the central axis of the coupling C. Of course, the coil 45 has a lead IJi extending from outside the casing C.
! (not shown) are connected. In addition, 48 in the figure is an atmosphere release port.

The exhalation valve device configured as described above performs the following operations. First, when the valve body 35 is opened and separated from the valve seat 34a, exhaled air from the valve seat member 34 passes through the exhaled air release space X and is released to the atmosphere from the release port 33. As the leaf spring 31 moves upward, the valve body 35 approaches the valve seat member 34, that is, its valve seat 34a, and the opening degree of the valve seat member 34, that is, the opening degree of the exhalation circuit is reduced. In this way, the opening degree of the exhalation circuit is adjusted according to the vertical displacement of the leaf spring 31.

The vertical position of the leaf spring 31 is changed by controlling the current applied to the coil 45. That is, when the coil 45 is energized, the energized coil 45 receives an electromagnetic driving force that displaces it in the vertical direction (Fleming's law), and the vertical displacement position of the coil 45 is determined by the leaf spring 31 and therefore This corresponds to the vertical displacement position of the valve body 35. This electromagnetic driving force increases as the current (voltage) applied to the coil 45 increases.
When the current is zero, the valve body 35 is thick (separated from the valve seat 34a, and the opening degree of the exhalation circuit is 100%). The amount of displacement in one direction is
It is increased as the current applied to the coil 45 becomes larger.

By controlling the current applied to the five coils 45 in this way, the opening degree of the valve seat member 34 and therefore the exhalation circuit can be varied in the range of 0 to 100%. And valve body 3
5 is pivotally supported by the leaf spring 31, so that the valve body 3
5 is seated in close contact with the valve seat 34a, thereby reliably preventing leakage of exhaled air when the valve is closed. Furthermore, if the setting force of the locking band is relatively small, when the valve body 35 is opened and separated from the valve seat 34a, the valve body 35 is always activated by receiving the exhalation pressure from the valve seat member 34. The position is corrected to be perpendicular to the seat 34a, and exhaled air can be evenly discharged from the entire circumference of the valve seat 3421 to the exhaled air release space X.

Here, the m-stone 41 can also be an electromagnet. In addition, the m stone 41 is attached to the leaf spring 31 flllll, and the coil 4
1 can also be provided on the casing C side.

However, it is better to provide the magnet 41 in the casing C, which requires a larger space and is heavier than the coil 45.
In terms of packaging, the leaf spring 31 and therefore the valve body 35
This is also preferable in terms of reducing the reciprocating inertia of the motor and improving its responsiveness.

Example of Use of Exhalation Valve Figure 2 shows an example of use of the exhalation valve device according to the present invention, and shows a case where it is used for PEEP pressure control.

In FIG. 2, reference numeral 51 denotes a 7-shaped common circuit, the merging end 1a of which is connected to the patient's lungs H (generally, it is airtightly connected to the patient's mouth via an adapter). Further, an inhalation circuit 2 is connected to one of the two branched ends 1b and lc, and an exhalation circuit 3 is connected to the other. This intake circuit 2 is connected to an air tank 4 as a pressure source, and the tank 4 stores air at a predetermined pressure that has been subjected to humidity adjustment and oxygen concentration adjustment in a known manner.

An electropneumatic converter 5 (voltage-air F converter) is connected to the intake circuit 2 as an intake pressure adjusting means. A valve seat member: 34) is connected via a joint 6.

Reference numeral 8 in FIG. 2 indicates control units 1 to 1 composed of microcomputers, which basically include CPU, [(OM, 1(ΔM
For this control unit 1-8, which is equipped with a pressure sensor 9 and I) FE E I) pressure setting switch IO
The control unit 8 outputs a signal Vl or ■2 to the front R electropneumatic converter 5 and the coil 45 of the discharge valve device. , detects the pressure in the common circuit l, and outputs the detected pressure to the control unit 8 as a voltage signal PΔ. In addition, the switch 10 of No. 7 is manually operated to set the P E E P pressure, that is, the target P E
E P f ", LH?1PEEP
A voltage signal PT corresponding to the current is output to the control unit 8.

In addition, in the example, the switch IO sets the PEEP pressure to 5 cm.
It can be set steplessly in the range of ~20cml1tO.

In the above configuration, the actual PEE of the common circuit 1
The P pressure, that is, the pressure detected by the pressure sensor 9, can be changed by the following factors, assuming that the patient's breathing state is in a certain stopped state. That is, (1) By changing the pressure of the intake circuit 2, the larger the intake pressure is, the greater the actual PEEP pressure PA becomes. This adjustment of the intake pressure is performed by removing the first electropneumatic converter 5.

(2) By changing the opening degree of the exhalation valve device (valve seat member 34), the smaller the opening degree, the greater the exhalation resistance from the exhalation circuit 3, and the larger the actual PEEP [EPA.

Next, the details of the control performed by the control unit 8 will be explained with reference to the flowchart shown in FIG. Note that in the following explanation, S indicates a step.

First, at Sl, the target PEEP pressure PT set by the switch 10 and the actual PEEP pressure PΔ of the common port iN1 detected by the pressure sensor 9 are read. Next, in S2, the differential pressure ΔP is calculated by subtracting P′■゛ from PA. In S3, it is determined whether the differential pressure ΔP is greater than or equal to zero. When, the actual PEEP pressure 1) The magnitude of A is the target PE
If the EP pressure is greater than or equal to PT, in this case, the electropneumatic converter 5
, output voltage signal Vl to the coil 45 of the exhalation valve device, ■2
is set as 84 or S5. Zunawaji, S
4, V2=O (no air supply from the intake circuit 2) is set. Further, in S5, Vl=KI XPT-Kl' XΔP is set.

In addition, Kn and +' are the wholesale gains, respectively.In this way, the actual PEEPI sat PA is the target PEEP
If the pressure is equal to or higher than PT, step S4. is performed to lower the actual PEEP pressure PA. Vl and ■2 at S5 are set.

After S5, Vl and v2 set as described above are outputted to the electropneumatic converter 5 or the coil 45 in S6.

On the other hand, if the determination in S3 is NO, the actual )) E
This is when the EP pressure PA is too smaller than the target PEEP pressure PT. In this case, first, in S7, (■) is converted into an absolute value, and then (1) and (2) are set in S8 and S9, and then, in S6, Vl and (2) are output to the electropneumatic converter or coil 45. This route from 87 to S9 is intended to increase the actual PEEP pressure PA, and V2- is set to 2X△P, and V1= is set to +x (pT+△P). Ru. Note that K is the control gain.

In this way, the actual PEEP pressure 1) A is the target I) F
:While comparing with EPPI3A, the electropneumatic converter 5 and the coil 45 of the exhalation valve device are controlled so that the pressure (actual PEEP pressure PA) of the common circuit is set from the target PI to EPffPA.
will be maintained. Note that the control gain of 7 and Kl' of 2 may be determined in advance through experiments.

Comparison with a conventional device Fig. 4 shows the effect of incorporating the exhalation valve device according to the present invention into a PEEP device (shown in Fig. 2) compared to a PEEP device using the conventional exhalation valve device. This shows the test equipment used to obtain data for comparison. Note that in FIG. 4, elements corresponding to those in FIG. 2 are indicated by IJ. In addition, as a PEEPW device incorporating a conventional exhalation valve device, the Bennett 7200a, which is currently said to be the highest standard in the world, is used, but since this uses a balloon type exhalation valve device, the Feedback control of the exhalation valve device is not performed (due to poor responsiveness, it is impossible to perform feedback control).

First, 21 in Figure 4 is IIA RV A RD A
It is called PP A RAT [J S and is a device that uses a type of cylinder device to artificially create a certain ay suction state. With this device 21, with a tJF volume of 670cc (volume of one breath), the number of breaths is 30/
Artificially created breathing for minutes. Also, 22 is Hora [・
A wire flow meter was connected to the common circuit 1' to measure the actual respiratory volume produced by the device 21. Furthermore, in order to investigate the fluctuation state of the PEEP pressure, the common circuit 1'
The actual pressure was measured by a pressure sensor 23 connected to the common circuit 1'. Then, for the intake circuit 2' and the exhalation circuit 3', a PE incorporating the exhalation valve device according to the present invention is provided.
Connecting an EP device or a conventional PEEP device, the respiratory volume and actual PE when this PEEP device is activated
An EP pressure P and a 1)-V diagram obtained from both of them were obtained. More specifically, each signal from the flow meter 22 and pressure sensor 23 is input to the microcomputer 24,
On the display 25, record rPJ, rVJ and rI) -
V-diagram" is now displayed.

The data (p-v diagram) obtained as described above are shown in FIGS. 5(a), (b) to FIG. 8(a), (b). In each figure, (a) shows the case where the exhalation valve device according to the present invention is used, and (b) shows the case where the conventional ay exhalation valve device is used. And Figure 5 is eye 1'W P E E
Figure 6 shows the target P E
Fig. 7 shows the case when the E P pressure is 10 cm H20, Fig. 8 shows the case when the E P pressure is 15 cm H2O, and Fig. 8 shows the case when the P L ball is 20 cm.
The figure shows the case of Hz O.

5(1)), (b) to FIG. 8(a) above.

As understood from (t)), the P E E I) device using the exhalation valve device according to the present invention is better than the conventional PFFE.
Compared to that of the P device, I) E IE )-) pressure (
It is understood that the fluctuation in (ii))) is extremely small, and as a result, the patient's work of breathing is significantly reduced (the work of breathing becomes p - v!! as the area enclosed in the figure becomes larger).

In the above embodiments, a case has been described in which the device is used for controlling the pressure of the expiratory valve device), but it is not limited to this, and may be used for controlling the expiratory pressure and the expiratory flow rate, etc. Further, the leaf spring 31 may have an elongated shape 17, and both ends of the leaf spring 31 may be held by the housing C.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view showing one embodiment of an exhalation valve device according to the present invention. Figure 2 shows an exhalation valve device according to the present invention.
A system diagram showing an example when used for pressure control. FIG. 3 is a flowchart showing an example of controlling the PEEP device shown in FIG. 2. FIG. 4 is an overall system diagram showing a test device used to compare the effects of the exhalation valve device according to the present invention with a conventional device. FIG. 5(a) to FIG. 8(a) are diagrams showing test results of a PEEP device using an exhalation valve device according to the present invention. FIG. 5(b) to FIG. 8(b) are diagrams showing test results of a PEEP device using a conventional exhalation valve device as is. C: Casing X: [l! Air release space Y: Drive mechanism storage chamber D = Drive mechanism 31: Leaf spring 34: Valve seat member 34a: Valve seat 36: Pivot bearing 41: Fifi stone 42: Inner rigid pole member 43: Outer magnetic pole 44: Coil holding part Month 45: Coil 1/ 41a 41 Figure 3 Figure 5 (b) (O) (b)
(0) Figure 7 (b) (0) Figure 8

Claims (3)

[Claims] (1) A casing, a leaf spring held in the casing, a valve seat member provided on the casing so as to face one side of the leaf spring, and attached to the leaf spring on one side of the leaf spring. a valve body that approaches and moves away from the valve seat member according to the displacement of the leaf spring in the thickness direction; and a valve body configured between the leaf spring and the casing on the other side of the leaf spring, An exhalation valve device for a respirator, comprising: electromagnetic driving means for driving the leaf spring in the thickness direction thereof by electromagnetic force. (2) Claim 1, wherein the valve body is pivotably supported by the leaf spring. (3) In claim 1, the electromagnetic drive means is comprised of a coil provided on the leaf spring and a magnet provided on the casing in correspondence with the coil.