JPH0328595B2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides a drive device for driving medical equipment such as an artificial heart or an intra-aortic balloon pump by alternately supplying positive pressure and negative pressure. Regarding.

(Prior art) As these drive devices, for example, Japanese Patent Laid-Open No. 58
-There is one shown in Publication No. 103466.

This device is equipped with a compressor as a positive pressure generating device and a vacuum pump as a negative pressure generating device. Each of these pumps was connected to an artificial heart pump, and the artificial heart was driven by alternately supplying positive pressure and negative pressure.

(Problems to be Solved by the Invention) However, this drive device requires two pressure generating devices: a compressor for generating positive pressure and a vacuum pump for generating negative pressure. Therefore, two motors are required to drive the pressure generator, and the power consumption of these motors is large. Furthermore, the drive device itself was naturally large.

Therefore, an object of the present invention is to reduce power consumption and downsize the device itself by generating positive pressure and negative pressure with one pressure generating device.

[Structure of the invention]

(Means for Solving the Problems) Therefore, in the present invention, a first pressure accumulator is connected to the output end of the pressure generation means that generates positive pressure and negative pressure through a first check valve, and the first pressure accumulator is connected to the output end of the pressure generation means that generates positive pressure and negative pressure. A second pressure accumulator was connected to the input end through a second check valve.

Further, in order to control the positive pressure stored in the first pressure accumulator, a first pressure detection means was connected to the first pressure accumulator, and a third on-off valve was provided at the output end of the pressure generation means. Furthermore, in order to control the negative pressure stored in the second pressure accumulator, a second pressure detection means was connected to the second pressure accumulator, and a fourth on-off valve was provided at the input end of the pressure generation means.

The third and fourth on-off valves are controlled by the electronic control device so that when the first on-off valve is open and the second on-off valve is closed, the detected pressure of the first pressure detection means is the first positive pressure. The opening/closing is controlled to be equal to the set value, and the first
When the on-off valve is closed and the second on-off valve is open, the opening and closing control is performed so that the detected pressure of the second pressure detection means is equal to the first negative pressure setting value.

(Operation) According to this, the positive pressure generated by the pressure generating means is supplied to the first pressure accumulator via the first check valve. Since the second pressure accumulator is connected to the input end of the pressure generating means via the second check valve, when positive pressure is generated by the positive pressure generating means, the second pressure accumulator is connected to the input end of the pressure generating means. fluid will be sucked through the second check valve. That is, the pressure generating means simultaneously generates positive pressure in the first pressure accumulator and negative pressure in the second pressure accumulator. Then, when the third on-off valve is opened, the positive pressure generated by the positive pressure generating means is released to the outside via the third on-off valve, so the positive pressure in the first pressure accumulator remains constant. It remains unchanged. Further, when the fourth on-off valve is opened, atmospheric air is supplied from the fourth on-off valve, so the negative pressure in the second pressure accumulator remains constant and does not change. In addition, a third on-off valve,
When both the fourth on-off valves are opened, no change occurs in the internal pressure of either the first pressure accumulator or the second pressure accumulator. Therefore, the third on-off valve and the third on-off valve are adjusted so that the detected pressures of the first pressure detection means and the second pressure detection means are equal to the preset first positive pressure setting value and first negative pressure setting value. By controlling the opening and closing of the on-off valve No. 4, the positive pressure and the negative pressure can be controlled to preferred pressures.

In this way, according to the above-mentioned means, both positive pressure and negative pressure can be generated with one pressure generating means. Therefore, only one motor is required to drive the pressure generator, and power consumption can be reduced. Moreover, the size of the device itself becomes small.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. This will be explained with reference to FIG. Compressa 10
is driven by a motor 11. The output end of this compressor 10 is connected to the input end of a first check valve 12. The output end of the first check valve 12 is connected to a first pressure accumulator 13 . Further, the first pressure accumulator 13 is connected to the first on-off valve 14, and the first pressure accumulator 13 is connected to the first on-off valve 14.
The output end of the on-off valve 14 is connected to the input end of the second on-off valve 15. The output end of the second on-off valve 15 is connected to the second pressure accumulator 16.
6 is connected to the input end of the second check valve 17. The output end of the second check valve 17 is connected to the compressor 1
Connected to the 0 input terminal. As described above, the output end and the input end of the compressor 10 form one closed loop via their respective devices.

A first pressure detection means 21 is connected between the first pressure accumulator 13 and the first on-off valve 14 .
Further, a second pressure detection means 22 is connected between the second pressure accumulator 16 and the second on-off valve 15.

Further, an input end of a third on-off valve 18 is connected between the output end of the compressor 10 and the first check valve 12. Further, an output end of a fourth on-off valve 19 is connected between the input end of the compressor 10 and the second check valve 17. And the third
The output end of the on-off valve 18 and the input end of the fourth on-off valve 19 are connected, and between them, the third check valve 2
0 output end and an orifice 23 which is a resistance means.
is connected. For this reason, the third on-off valve 18
The output end of the third on-off valve 19 and the input end of the fourth on-off valve 19 are
Atmospheric air can easily flow in through the check valve 20, but air can flow out with resistance determined by the orifice 23. Since the compressor 10 is designed to operate most efficiently under a predetermined load, when the compressor 10 is operated under no load, the compressor 10
Very loud noise may be generated from the output end of the In this embodiment, the air is discharged through the orifice 23, so the compressor 1
The structure is such that the noise generated from the zero output terminal does not easily leak to the outside of the drive device.

The first pressure detection means 21 and the second pressure detection means 22 are input to the electronic control means 30. Furthermore, a first on-off valve 14, a second on-off valve 15, a third on-off valve 18, a fourth on-off valve 19, and a motor 10 are connected as outputs of the electronic control device 30, respectively.

Furthermore, in the drive device configured as described above, the output section 40 is provided between the first on-off valve 14 and the second on-off valve 15. Note that the output unit 40 is connected to medical equipment via an adapter 50, which will be described later.

Next, the adapter 50 is shown in FIG. This is to prevent air used in the drive device from getting mixed in when an artificial heart or the like is driven using a gas such as helium gas. This will be explained with reference to FIG. Adapter 50 connects housings 51 and 5
The primary side port 51 is connected to the diaphragm 53 sandwiched between the two
The diaphragm 53 partitions a space communicating with the port 52a from a space communicating with the secondary port 52a.
is movable in the horizontal direction shown in the figure. Plates 54 and 55 are attached to the center of the diaphragm 53 so as to sandwich the diaphragm 53 therebetween. A regulating member 56 for regulating the amount of displacement of the plate 54 is attached to the center of the housing 51. The regulating member 56 is engaged with the housing 51 through a screw 56a. This regulating member 56
When rotated, the engagement position changes and the regulating member 56
moves left and right. If you move to the left, plate 5
The movement range of plates 4 and 55 becomes larger, and if they move to the right, the movement range of plates 54 and 55 becomes smaller. With the above configuration, the output end of the first on-off valve 14 and the second on-off valve 15 are connected to the primary port 51a.
A helium gas supply mechanism, an artificial heart pump, etc. are connected to the secondary port 52a. Note that the description of the helium gas supply mechanism is omitted here.

Next, the electronic control device 30 will be explained. In this embodiment, it is composed of a microcomputer. The general operation of this microcomputer will be explained using the flowcharts shown in FIGS. 3 and 4. Figure 3 shows the main routine. When the power is turned on, the output ports and memory are cleared and parameters are set to initial values.
For example, when used in an artificial heart, the parameters include the heart rate and the duty ratio of the heartbeat. Next, an interrupt wait is executed.

This interrupt processing is shown in FIG. counter co
is incremented by one each time an interrupt process is performed. When this count value reaches R (a time parameter determined by the heart rate), the count value is cleared to 0. When the value of the counter CO reaches 0, the first on-off valve 14 is opened and the second on-off valve 15 is opened.
Set to closed. As a result, the first on-off valve 1
Positive pressure is supplied to the adapter 50 via 4. When the value of the counter CO reaches D, the first on-off valve 14
is closed, and the second on-off valve 15 is opened. As a result, negative pressure is applied to the adapter 5 via the second on-off valve 15.
0. Then, when the counter CO reaches R, the count value is cleared to 0. As described above, the first and second on-off valves 1 are
4 and 15 are controlled to supply positive pressure and negative pressure to the adapter 50. Then, the heart rate and its timing are determined by the set values R and D of the counter CO.

Next, returning to FIG. 3, the pressure setting process will be explained.
In this example, the first on-off valve 14 and the second on-off valve 1
There are two states depending on the open and closed states of 5, and the pressure setting is also controlled separately for these two states. When the interrupt processing is finished, the first on-off valve 14 is open and the second on-off valve 15 is closed (positive pressure application mode).
If the positive pressure application mode is selected, the detected pressure of the first pressure detection means 21 is determined in step S4.
Pm is compared with the first positive pressure set value Ps1. At this time,
When the detected pressure Pm of the first pressure detection means 21 is smaller than the first positive pressure setting value Ps1, the third on-off valve 1
8 is closed, and the fourth on-off valve 19 is opened. As a result, atmospheric air is supplied to the input end of the compressor 10 via the fourth on-off valve 19, and all positive pressure obtained from the output end of the compressor 10 is supplied to the input end of the compressor 10 via the first check valve 12. is supplied to the pressure accumulator 13. Therefore, while positive pressure is being supplied to the adapter 50 in the positive pressure mode, if the positive pressure is less than a predetermined value, the positive pressure is supplied by the above control.

Next, while supplying positive pressure to the adapter 50 in the positive pressure mode, if the detected pressure Pm of the first pressure detection means 21 is greater than the first positive pressure set value Ps1, the positive pressure is sufficient to the predetermined value. Therefore, the second pressure detection means 21
Check (step S6). Note that, in this case, the mode is positive pressure mode and negative pressure is not being supplied, so the following steps are for performing control in case the mode becomes negative pressure mode next time. first,
When the detected pressure Vm of the second pressure detection means 22 is larger than the second negative pressure set value Vs2, that is, when the negative pressure has not reached the set value Vs2, the third on-off valve 18 is opened. , the fourth on-off valve 19 is closed. Thereby, the input end of the compressor 10 reduces the pressure in the second pressure accumulator 16 via the second check valve 17. At this time, since the third on-off valve 18 is open, due to the action of the first check valve 12,
The pressure within the first pressure accumulator 13 is not affected. Next, the detected pressure of the second pressure detection means 22
If Vm is smaller than the second negative pressure setting value Vs2,
Since the negative pressure in the second pressure accumulator 16 is sufficient to a predetermined value, both the third on-off valve 18 and the fourth on-off valve 19 are opened. As a result, the compressor 10
It will be driven in a state close to no load.

Here, the reason why the negative pressure in the second pressure accumulator 16 is set to the second negative pressure set value Vs2 in the positive pressure mode is as follows. In other words, it is necessary for an artificial heart to be driven so as to give blood a pulsation as close as possible to that of a living heart.
For this purpose, it is necessary to supply accurate pressure to the artificial heart at a predetermined timing depending on the condition of the living body. However, since this type of drive device drives an artificial heart or the like by switching between positive pressure and negative pressure, a large amount of air is consumed during the switching. Therefore, in order to prevent a large drop in pressure and to stabilize the pressure, an accumulator is used to store positive pressure and negative pressure. but,
Unless a very large accumulator is used, it is difficult to prevent the pressure from decreasing, and conversely, if the pressure changes due to the use of an accumulator, it will take time to restore it to its original value. Therefore, in this embodiment, in order to abruptly change the pressure applied to the artificial heart at the timing of rising and/or falling at the moment of switching from one of positive pressure and negative pressure to the other, for example,
In positive pressure mode, which applies positive pressure to the artificial heart,
The second pressure accumulator 16 is set to be lower than a predetermined negative pressure, and then the first and second on-off valves 14, 1
5 to apply negative pressure to the artificial heart, a negative pressure greater than a predetermined value is applied. This makes the fall time abrupt and prevents an operation delay.

In this embodiment, the volumes of the first and second pressure accumulators for accumulating the pressure are 100 c.c.

Next, control in the negative pressure mode will be explained.
When the counter CO reaches D, the first on-off valve 14 is closed and the second on-off valve 15 is opened to set the negative pressure mode. In this negative pressure mode, first, the detected pressure Vm of the second pressure detection means 22 is set to the first negative pressure setting value.
Compare with Vs1 (step S10). The detected pressure Vm of the second pressure detection means 22 is the first negative pressure set value Vs1
When it is larger, the third on-off valve 18 is opened and the fourth on-off valve 18 is opened.
The on-off valve 19 is closed. As a result, the air in the second pressure accumulator 16 is released via the second check valve 17 to compensate for the lack of negative pressure. At this time, the first pressure accumulator 13 does not change due to the action of the first check valve 12.

The detected pressure Vm of the second pressure detection means 22 is the first
When the negative pressure is smaller than the negative pressure set value Vs1, sufficient negative pressure has been obtained, and the pressure in the first pressure accumulator 13 is then controlled to switch to the positive pressure mode. That is, as described above, the pressure in the first pressure accumulator 13 is controlled to the second positive pressure set value, which is greater than the set value. For this purpose, the detected pressure Pm of the first pressure detection means 21 is first compared with the second positive pressure set value Ps2. Detection pressure Pm of the first pressure detection means 21
is smaller than the second positive pressure set value Ps2, the third on-off valve 18 is closed and the fourth on-off valve 19 is opened. This causes the compressor 10 to apply positive pressure to the first
is supplied to the first pressure accumulator 13 through the check valve 12, and the pressure within the first pressure accumulator 13 increases. When the detected pressure Pm of the first pressure detection means 21 becomes larger than the second positive pressure set value Ps2, both the third and fourth on-off valves 18 and 19 are opened, and the compressor 10 is brought to a state close to no load. drive in the state.

By the above control, the positive pressure and the negative pressure can be controlled to the predetermined first and second positive pressure set values Ps1 and Ps2 and the first and second negative pressure set values Vs1 and Vs2. These values are Vs2≦Vs1≦0mmHg≦Ps1
≦Ps2. In this embodiment, each value is determined by the following relational expression.

Ps2=Ps1 (1+α) 0≦α≦0.65 Vs2=Vs1 (1−β) 0≦β≦0.65 These values of α, β, Ps1, and Vs1 can be arbitrarily set from the outside.

Further, the setting range of Ps1 and Vs1 can be set within the following range, for example: 0 mmHg≦Ps1≦350 mmHg -300 mmHg≦Vs1≦0 mmHg.
The reason why each setting value is variable in this way is that the parameters differ depending on the volume of the medical device being driven.
This is also because the driving conditions of the medical device change depending on the conditions of the living body.

[Effects] According to the present invention, positive pressure can be supplied when the first on-off valve is opened, and negative pressure can be supplied when the second on-off valve is opened. When the third on-off valve is opened, the positive pressure generated by the positive pressure generating means is released to the outside via the third on-off valve, so the pressure in the first pressure accumulator remains constant. It does not change. Also, the fourth
When the on-off valve is opened, atmospheric air is supplied from the fourth on-off valve, so the pressure in the second pressure accumulator remains constant and does not change. Further, when both the third on-off valve and the fourth on-off valve are opened, no change occurs in the internal pressure of either the first pressure accumulator or the second pressure accumulator. Therefore, the third on-off valve and the third on-off valve are adjusted so that the detected pressures of the first pressure detection means and the second pressure detection means are equal to the preset first positive pressure setting value and first negative pressure setting value. By controlling the opening and closing of the on-off valve No. 4, the positive pressure and the negative pressure can be controlled to preferred pressures.

Therefore, the present invention can generate both positive pressure and negative pressure with one pressure generating means. Therefore, only one motor is required to drive the pressure generator, and power consumption can be reduced. Furthermore, the size of the device itself can be made small.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an embodiment of the medical device driving device of the present invention, Fig. 2 is a sectional view showing an adapter, and Figs. 3 and 4 show the operation of a microcomputer that is an electronic control device. It is a flowchart. 10...Compressor, 11...Motor, 12
...First check valve, 13...First pressure accumulator, 14
...First on-off valve, 15... Second on-off valve, 16
...Second pressure accumulator, 17...Second check valve, 18
...Third on-off valve, 19... Fourth on-off valve, 20
... Third check valve, 21 ... First pressure detection means, 22 ... Second pressure detection means, 23 ... Orifice, 30 ... Microcomputer (electronic control device), 40 ... Output section , 50...adapter.

Claims (1)

[Claims] 1. Pressure generating means for generating positive pressure and negative pressure, a first check valve whose input end is connected to the output end of the pressure generating means, and the first check valve. a first pressure accumulator connected to the output end of the pressure accumulator, a first on-off valve connected to the first pressure accumulator, and a pressure between the first check valve and the first on-off valve. a second on-off valve connected to the output end of the first on-off valve; and a second on-off valve connected to the second on-off valve.
a second check valve whose input end is connected to the second pressure accumulator and whose output end is connected to the input end of the pressure generating means; and an input of the first check valve. a third on-off valve connected to the end; a second pressure detection means for detecting pressure between the second check valve and the second on-off valve; and an output of the second check valve. a fourth on-off valve connected to the end; an output section provided between the first on-off valve and the second on-off valve; The first on-off valve and the second on-off valve are controlled to open and close at predetermined timings depending on the state of the living body, and the third on-off valve
and the fourth on-off valve so that when the first on-off valve is open and the second on-off valve is closed, the detected pressure of the first pressure detection means is equal to the first positive pressure setting value. When the first on-off valve is closed and the second on-off valve is open, the opening and closing control is performed so that the detected pressure of the second pressure detection means is equal to the first negative pressure set value. A medical equipment drive device comprising an electronic control device. 2. The output end of the third on-off valve and the input end of the fourth on-off valve are connected, and the third check valve and the resistance means enable communication with the atmosphere. The medical device drive device described in Section 1. 3. The electronic control device further includes a second positive pressure setting value set higher than the first positive pressure setting value and a second negative pressure setting value set lower than the first negative pressure setting value. , the first on-off valve is open and the second on-off valve is open.
When the on-off valve is closed, the detected pressure of the second pressure detection means is controlled to the second negative pressure setting value, and the first
The medical device driving device according to claim 1, wherein when the on-off valve is closed and the second on-off valve is open, the detected pressure of the first pressure detection means is controlled to a second set value. .