JPH05288162A - Pumping device - Google Patents

Abstract

PURPOSE:To prevent pumping from being interrupted or stopped for a long period of time due to the abnormality of a pressure detection signal by detecting the abnormality of the detection signal of a pressure sensor, and increasing suction pressure at the change rate higher than the low change rate at the time of the pressure becoming less than the set pressure. CONSTITUTION:The output port pressure of a linear motor liquid pump 12 is detected by a pressure sensor 61. When the detected pressure is out of a first set range, the buildup speed of negative pressure is lowered to 1/2, and when the detected pressure is out of a second set range, the buildup of negative pressure is stopped. Monitor pulses are placed on the signal line of the pressure sensor 61 and counted during the initial suction period, and when the count value reaches the set value 51 or more, the pressure sensor system is judged to be abnormal. At the abnormal time of the pressure sensor system, the buildup of negative pressure is performed at the same speed as the steady time, disregarding the detection signal of the pressure sensor 61. The strong suction of living body tissue is thereby avoided, and the stop of suction caused by the intermixture of a wrong signal, the defect of a circuit, and the like can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid pump which drives a reciprocating member with a linear motor.

[0002]

2. Description of the Related Art For example, in an artificial heart, a diaphragm is housed in a working chamber in an outer container, the blood chamber and the working chamber are separated by this diaphragm, and a high pressure (high pressure air) and a low pressure (suction pressure) are provided in the working chamber. The blood chambers are alternately provided, and the blood chambers are connected to the suction port via the first check valve and communicate with the discharge port via the second check valve. When a high pressure is applied to the working chamber, the diaphragm is pressurized and tries to contract the blood chamber, whereby the fluid (blood) in the blood chamber is discharged to the discharge port via the second check valve. When the working chamber is switched to the low pressure, the diaphragm is sucked into the working chamber and tries to expand the blood chamber, whereby the fluid (blood) is sucked into the blood chamber from the suction port through the first check valve. Therefore, by alternately applying positive pressure and negative pressure to the working chamber of the artificial heart, the artificial heart causes the fluid (blood) to flow into the suction port.
Is inhaled and discharged to the discharge port. The artificial heart is driven by alternating high / low pressure (air) in its working chamber.

Conventionally, the high / low pressure (air) is supplied by an air pumping device. This pumping device includes an electric motor, an air pump driven by the electric motor, a high-pressure accumulator to which the discharge pressure of the air pump is applied, a low-pressure accumulator to which the suction pressure of the air pump is applied, a high-pressure accumulator and a low-pressure accumulator. It is composed of a high-pressure electromagnetic on-off valve and a low-pressure electromagnetic on-off valve that are selectively connected to the chamber (for example, JP-A-58-99967 and JP-A-58-169460).
Gazette), by supplying high pressure air to the air chamber of the artificial heart by closing the low pressure solenoid on-off valve and opening the high pressure solenoid on-off valve, and by closing the high pressure solenoid on-off valve and opening the low pressure solenoid on-off valve. A low pressure (suction pressure) is applied to the air chamber of the artificial heart.

For example, this type of pumping device includes many components such as an electric motor, an air pump, an accumulator and high and low pressure electromagnetic on-off valves. Moreover, since the accumulator and the like occupy a relatively large space, the entire apparatus becomes relatively large. For example, if an accumulator is omitted and a reciprocating pump is used to directly apply high pressure (discharge pressure) / low pressure (suction pressure) to the artificial heart, the working fluid, air, is compressible, resulting in volumetric contraction of the working fluid. Since there is expansion and the amount of air pressure rise / fall relative to the reciprocating stroke of the pump is small, the rise of pressure when switching from suction to discharge is delayed, and the fall of pressure when switching from discharge to suction is delayed. The pump needs to be relatively large and high-powered.

Japanese Unexamined Patent Publication No. 59-28969 discloses a pumping device which intermittently presses a bag containing a gas or a liquid to be supplied to a working fluid chamber of an artificial heart with a linear motor. According to this, since the high and low pressure electromagnetic on-off valves can be omitted, the number of device elements is reduced, but when the working medium is gas, it is compressible, so when switching from suction to discharge. Since the rise of pressure is slow and the fall of pressure at the time of switching from discharge to suction is slow and the working fluid absorbs the pressure, the volume of the device cannot be made particularly small.

When the working medium is an incompressible fluid, that is, a liquid, the pressure rises quickly when the suction is switched to the discharge, and the pressure falls quickly when the discharge is switched to the suction. Since there is no pressure absorption due to, the volume of the device can be significantly reduced. However, when the artificial heart is pumped by using a non-compressible working medium, for example, a liquid such as silicone oil, a negative pressure (absolute value) of negative pressure (absolute value) is generated in the artificial heart suction step (suction step of the pumping device). The rising speed is fast, the rise of the blood suction force by the cannula that is connected to the living heart and guides the living blood to the artificial heart rises quickly, and the working medium is incompressible.
If the blood collection speed of the living body at the tip of the cannula is relatively slow with respect to this speed, or if the living tissue is too close to the tip of the cannula, the living tissue will enter the cannula. Is aspirated, which reduces the amount of blood aspirated by the cannula and makes tissue tissue aspiration stronger,
The living tissue is damaged.

In order to prevent this, the applicant of the present invention integrates the energization current value during the discharge drive of the linear motor drive which supplies a fluid to the artificial heart and gives a pulsating pressure to the fluid to determine the suction pressure of the fluid pump. When detected by the pressure sensor and the integrated value reaches the set value, a current for suction is applied to the linear motor to gradually increase the current value, and when the suction pressure (absolute value) exceeds the set value,
Therefore, a pumping device for stopping the gradual increase of the linear motor energization current value is provided (JP-A-2-206467 and JP-A-2-206467).

According to this, the blood collecting speed of the living body to the tip of the cannula is slow, or the living tissue is too close to the tip of the cannula and the living tissue is sucked into the cannula. , As a result, when the blood suction of the cannula becomes less and the suction of the living tissue becomes stronger, the gradual increase of the energizing current value of the linear motor stops,
Therefore, the increasing speed of the suction pressure decreases. That is, the suction speed is automatically reduced to match the blood collection amount. Therefore, the living tissue is not strongly sucked by the cannula, and the probability of damaging the living tissue is reduced.

The applicant of the present invention further proposes, as a modification of this, Japanese Patent Application No.
No. 411684, a technique is proposed in which, when (absolute value of) suction pressure returns to within a set range, a gradual increase in energizing current value is set as a low rate of change after that for a certain period of time, and as soon as it returns to the set range, rapid suction is relieved. On the other hand, Japanese Patent Application No. 3-8902
In No. 0, when the suction pressure (absolute species) exceeds the first set value, the linear motor energizing current value gradually increases at a rate of 1/2, and when it exceeds the second set value, the energizing current value increases. A technique was proposed to stop the gradual increase and smoothly shift the suction pressure change.

[0010]

By the way, in the pressure detection circuit including the pressure sensor, noise or an abnormal signal indicating excessive suction pressure is mixed in the signal line, or the suction pressure is excessive due to defective pressure sensor or pressure determination circuit. When a signal is abnormally generated, the gradual increase in the energizing current value stops, and if it continues relatively frequently or for a long period of time, not only a thrombus is formed in the artificial heart but also the living heart can be assisted. Disappear.

The present invention aims to remedy this type of problem.

[0012]

The pumping device of the first invention of the present application has a fluid space (50) communicating with a fluid output port (15) and containing an incompressible liquid (silicone oil). Reciprocating members (18,19) that shrink / enlarge, reciprocating members (18,19)
(30) for reciprocating the electric field, and a magnetic field in a direction orthogonal to the extending direction of the electric coil (30) is applied to the electric coil (30) to correspond to the forward / reverse energization direction of the electric coil (30). Magnetic field generating means (25 ~ 2
8), a linear motor driven liquid pump (12); pressure detection means (61) for detecting the pressure of the fluid output port (15) or the flow path communicating therewith; detection signal of the pressure detection means (61) Sensor abnormality detecting means (480, 43) for detecting an abnormality; energizing means (31) for energizing the electric coil (30) forward / reverse; and a fluid space (50 for communicating with the fluid output port (15) ) Is energized to drive the reciprocating member (18, 19) in the direction of enlarging, the pressure detected by the pressure detection means (61) is the set pressure (a, b).
In the above case, the energizing current value of the electric coil (30) is sequentially changed through the energizing means (31) at a predetermined rate of change (ΔT) in the direction of increasing the expansion, and the pressure detecting means (61) is When the detected pressure is less than the set pressure (a, b), the rate of change is reduced (Δ
T / 2,0) and the sensor abnormality detection means (480,43) detects an abnormality in the detection signal, the rate of change (ΔT
Current value control means (43); which sequentially changes the energizing current value at a rate of change (ΔT) higher than / 2,0). The pumping device of the second invention of the present application is a fluid space (50) communicating with a fluid output port (15) and containing an incompressible liquid (silicone oil).
Reciprocating member (18,19), Reciprocating member (18,1)
The electric coil (30) for driving the electric coil (30) back and forth and a magnetic field in a direction orthogonal to the extending direction of the electric coil (30) are applied to the electric coil (30) in the forward / reverse energizing directions. Magnetic field generating means (25
~ 28), a linear motor driven liquid pump (12);
The pressure detecting means (61) for detecting the pressure of the fluid output port (15) or the flow path communicating with the fluid output port (15); the energizing means (31) for energizing the electric coil (30) forward / reversely; and the pressure detecting means (61) When the detected pressure is less than the set pressure (a, b), the signal (c,
d = H) generating comparison means (46a, 46b); the comparison means (46a, 46b)
b) Generated signal (c, d = H) The signal line (h) that transmits the same level change as the signal (c, d = H) indicating less than the set pressure at the set cycle (500Hz = 2msec) Monitor signal generating means (48) for giving; a fluid space communicating with the fluid output port (15)
In energizing the reciprocating members (18, 19) in the direction of enlarging (50), the signal level appearing on the signal line (h) at a predetermined period (1 msec) from the beginning of the set time (100 msec) is changed. Check and measure the number of times it was a signal level (H) indicating less than the set pressure, and when the number of times during the set time (100 msec) is the set value (51) or more, the sensor abnormality information (ADF = H) is displayed. Generated pressure signal abnormality detection means (43); and pressure during energization for driving the reciprocating members (18, 19) in a direction to expand the fluid space (50) communicating with the fluid output port (15). When the pressure detected by the detection means (61) is equal to or higher than the set pressure (a, b), the energization current value of the electric coil (30) is passed through the energization means (31) at a predetermined rate of change (ΔT). The pressure detected by the pressure detection means (61) is changed to the set pressure by gradually changing the direction to increase the expansion.
When it is less than (a, b), the rate of change is reduced (ΔT / 2, 0), and when the pressure signal abnormality detection means (43) generates sensor abnormality information (ADF = H), the pressure is less than the set pressure. The current value control means (43) for sequentially changing the energizing current value at a change rate (ΔT) higher than the change rate (ΔT / 2,0). The pumping device of the third invention of the present application is a reciprocating member (18) for reducing / enlarging a fluid space (50) communicating with a fluid output port (15) and containing an incompressible liquid (silicone oil). , 19), an electric coil (30) for reciprocally driving the reciprocating member (18, 19), and a magnetic field in a direction orthogonal to the extending direction of the electric coil (30).
Magnetic field generating means (25 to 2) that gives to the electric coil (30) forward and backward moving forces corresponding to the forward and reverse energizing directions
8), a linear motor driven liquid pump (12); pressure detecting means (61) for detecting the pressure of the fluid output port (15) or the flow path communicating therewith; forward / reverse energization to the electric coil (30) Energizing means (31) for turning on; a signal (c = H) indicating this when the pressure detected by the pressure detecting means (61) is less than the first set pressure (a)
A first comparing means (46a) for generating on the signal line (h); the pressure detected by the pressure detecting means (61) is less than the second set pressure (b), a signal indicating this (d = H) No. generated on signal line (h)
2 Comparing means (46b); the signal line (h), the level change similar to the signal (a, b = H) indicating less than the set pressure is set cycle (500H
z = 2msec) monitor signal generating means (48); in energization for driving the reciprocating members (18, 19) in a direction of expanding the fluid space (50) communicating with the fluid output port (15), From the beginning of the set time (100 msec) for a predetermined period (1 msec), check the signal level appearing on the signal line (h) and measure the number of times it was the signal level (H) indicating less than the set pressure. Pressure signal abnormality detection means (43) for generating sensor abnormality information (ADF = H) when the number of times during a set time (100 msec) is a set value (51) or more; and the fluid output port (15) When the pressure detected by the pressure detecting means (61) is equal to or higher than the first set pressure (a) during energization for driving the reciprocating members (18, 19) in the direction of expanding the fluid space (50) communicating with At a rate of change (ΔT) through the energizing means (31) to sequentially change the energizing current value of the electric coil (30) in the direction of increasing the expansion, and the pressure detecting means (61) When the released pressure is less than the first set pressure (a) and the second set pressure (b) or more, the rate of change is reduced to a low value (ΔT / 2), and the pressure detected by the pressure detection means (61) is 2 When the pressure is less than the set pressure (b), the sequential change of the energizing current value is stopped, and when the pressure signal abnormality detection means (43) generates sensor abnormality information (ADF = H), the pressure is less than the first set pressure (a). A current value control means (43); which sequentially changes the energization current value at a change rate (ΔT) higher than the change rate (ΔT / 2) when the pressure is equal to or higher than the second set pressure (b).

A pumping device according to a fourth invention of the present application is
An incompressible liquid (silicone) that communicates with the fluid output port (15).
Reciprocating member (18, 19) for reducing / enlarging the fluid space (50) in which the oil (oil) is stored, an electric coil (30) for reciprocating the reciprocating member (18, 19), and an electric coil ( Magnetic field generating means (25 to 28) for applying a magnetic field in a direction orthogonal to the extending direction of the (30) to the electric coil (30) to generate a forward / backward moving force corresponding to the forward / reverse energization direction in the electric coil (30). ), A linear motor driven liquid pump (12); fluid output port (15)
Alternatively, a pressure detecting means (61) for detecting the pressure of a flow path communicating therewith; an energizing means (31) for supplying a forward / reverse current to the electric coil (30); a pressure detected by the pressure detecting means (61) is the first First comparing means (46a) for generating a first signal (c = H) indicating this when the pressure is less than the set pressure (a); the pressure detected by the pressure detecting means (61) is less than the second set pressure (b) The second signal (d = H) that indicates this when
Second comparison means (46b) for generating; set cycle (500Hz = 2msec)
A monitor signal generating means (48) for generating a monitor signal (f) exhibiting a level change similar to that of the second signal (d = H); the monitor while the first signal (c = H) is generated. Monitor signal transmitting means (47c) for transmitting the signal (f) to the signal line (h); the second signal
Second signal transmitting means for transmitting (d = H) to the signal line (h)
(47d); Fluid space (50) communicating with the fluid output port (15)
When energizing to drive the reciprocating members (18, 19) in the direction to expand the, a predetermined period from the beginning of the current for a set time (100 msec)
(1 msec) Check the signal level appearing on the signal line (h) and measure the number of times it was the signal level (H) equivalent to the second signal, and the number of times during the set time (100 msec) is the set value
(51) Pressure signal abnormality detection means (43) for generating sensor abnormality information (ADF = H) when above, and the fluid output port (1
Reciprocating member in the direction of expanding the fluid space (50) communicating with 5)
When energizing to drive (18, 19), check the signal level appearing in the signal line (h) at a predetermined cycle (1 msec) and if it is not the signal level (H) equivalent to the second signal (d = H), The energizing current value of the electric coil is changed by a predetermined step through the energizing means (31) in a direction to increase the expansion,
When the signal level (H) corresponding to the signal (d = H) is held, this change is suspended, but when the pressure signal abnormality detection means (43) is generating sensor abnormality information (ADF = H), a predetermined step is changed, A current value control means (43); is provided.

Symbols in parentheses indicate corresponding elements or matters in the embodiments shown in the drawings and described later.

[0015]

When the pumping devices of the first to fourth inventions of the present application are used, for example, for driving the artificial heart described above, the liquid pump (12) driven by the linear motor has its fluid output port (1).
Through 5), high pressure (discharge pressure) and low pressure (suction pressure) are alternately applied to the working chamber of the artificial heart through the incompressible liquid (silicone oil). This is done by the energizing means (31) alternately energizing the electric coil (30) of the liquid pump (12) forward / reverse. Since the liquid pump (12) supplies the incompressible hydraulic fluid to the artificial heart in this way, the pressure rises quickly when switching from suction to discharge, and the pressure rises when switching from discharge to suction. Since the descending speed is fast and there is no pressure absorption by the working fluid, the accumulator and the high and low pressure electromagnetic on-off valves that are components of the conventional pumping device can be omitted, that is, the mechanical elements of the pumping device can be reduced and the device volume can be reduced. ..

By the way, when used for driving an artificial heart, for example, when the blood collecting speed at the tip of the cannula is slow and / or when the biological tissue is too close to the tip of the cannula, In the suction process of the pumping device, the contraction of the spatial volume of the working liquid chamber of the artificial heart slows down with respect to the increasing speed of the suction pressure of the output port of the pumping device, and the suction pressure of the working liquid chamber (output port) increases. To do. This suction pressure is detected by the pressure detecting means (61). Then, the current value control means (43) reduces the rate of change (ΔT / 2,0) when the pressure detected by the pressure detection means (61) becomes less than the set pressure (a, b). Since the suction speed is slowed down, strong suction of the living tissue to the cannula is avoided and the probability of damaging the living tissue is reduced.

By the way, such a gradual stop of suction pressure
If it occurs due to abnormality of each electric element or signal line (h) between the pressure detection means (61) and the current value control means (43) or mixing of noise, pumping may be interrupted or stopped for a long time. Not only does the blood clot form in the artificial heart, but it cannot support the living heart.

In the first invention of the present application, the sensor abnormality detecting means (480, 43) detects the abnormality of the detection signal of the pressure detecting means (61), and in response thereto, the current value control means (43) , The suction pressure is increased at a change rate (ΔT) higher than the low change rate (ΔT / 2,0) when the pressure is lower than the set pressure (a, b). This prevents the pumping from being interrupted or being stopped for a long period of time due to an abnormality in the pressure detection signal.

In the second invention of the present application, comparing means (46a, 4a
6b), the pressure detected by the pressure detection means (61) is the set pressure (a, b)
A signal indicating this (c, d = H) when less than, and the monitor signal generating means (48) transmits the signal (c, d = H) generated by the comparing means (46a, 46b). The same level change as the signal (c, d = H) indicating less than the set pressure is set on the line (h) at the set cycle (500 Hz =
2 msec), the pressure signal abnormality detection means (43) drives the reciprocating members (18, 19) in the direction of enlarging the fluid space (50) communicating with the fluid output port (15). From the beginning of the set time (100 msec) for a predetermined period (1 msec), check the signal level appearing on the signal line (h) and measure the number of times it was the signal level (H) indicating less than the set pressure. When the number of times during the set time (100 msec) is the set value (51) or more, the sensor abnormality information (ADF = H) is generated.

During energization for driving the reciprocating members (18, 19) in the direction of enlarging the fluid space (50) communicating with the fluid output port (15), from the beginning to a set time (100 msec) ,
Immediately before that, the pressure of the output port (15) was high and the pressure did not fall below the set value (b), and in normal times, the count value (ADC) is the monitor signal generating means ( 48) is the signal level count value that is less than the set value (51) (50
Below). However, in the case of an abnormality such as noise or an abnormal signal mixed in the pressure detection means (61) to the signal line (h), or a defect of those circuit elements, the count value (AD
C) becomes the set value (51) or more, at this time the pressure signal abnormality detection means (43) generates sensor abnormality information (ADF = H), and in response to this sensor abnormality information (ADF = H), the current value Control means (43)
However, the low rate of change when the pressure is less than the set pressure (a, b)
Increase suction pressure at a rate of change (ΔT) higher than (ΔT / 2,0).
This prevents the pumping from being interrupted or being stopped for a long period of time due to an abnormality in the pressure detection signal.

In the third and fourth inventions of the present application, when the pressure detected by the pressure detecting means (61) is equal to or higher than the first set pressure (a), the energizing means (at a predetermined rate of change (ΔT) ( 31) through the electric current value of the electric coil (30) is sequentially changed to increase the expansion, the pressure detected by the pressure detection means (61) is less than the first set pressure (a) second set pressure (b) When it is more than the above, the rate of change is reduced to a low value (ΔT / 2), and when the pressure detected by the pressure detection means (61) is less than the second set pressure (b), the energizing current value is sequentially changed. The effect of preventing strong suction of the living tissue to the cannula is further enhanced by stopping. In addition, as in the second aspect of the invention, in the case of an abnormality such as noise or an abnormal signal mixed in the pressure detection means (61) to the signal line (h), or a defect of those circuit elements, the count value ( ADC) becomes the set value (51) or more,
At this time, the pressure signal abnormality detection means (43)
DF = H), and in response to this sensor abnormality information (ADF = H), the current value control means (43) causes a low rate of change when the pressure falls below the set pressure (a, b) ( Change rate (ΔT) higher than ΔT / 2,0)
Increase the suction pressure with. This prevents the pumping from being interrupted or being stopped for a long period of time due to an abnormality in the pressure detection signal.

Other objects and features of each invention of the present application will be apparent from the following description of embodiments with reference to the drawings.

[0023]

FIG. 1 shows an embodiment of the present invention in a state of being connected to an artificial heart. The artificial heart 1 has a working chamber 3 in an outer container.
The diaphragm 2 is housed in the inner space 4 of the diaphragm 2.
It has a well-known structure in which the first cannula 7 is communicated with the suction check valve 5 and the second cannula 8 is communicated with the discharge check valve 6.
The cannula 7 is connected to the left atrium 10 of the living heart and the second cannula 8 is connected to the aorta 11. Artificial heart 1
The working chamber 3 containing the silicone oil 3 is connected to the output port 15 of the linear motor driven fluid pump 12 via the tube 9. The pressure of the working chamber 3 detected by the pressure sensor _61, the level of the voltage corresponding to the detected pressure, giving the pumping controller 42.

FIG. 1 shows a mode in which another set of artificial hearts 101 is connected to a living heart. This artificial heart 10
One working chamber is connected to the output port 1501 of another fluid pump 1201 via the tube 9. The fluid pump 1201 has exactly the same structure as the fluid pump 12 and the same dimensions. The pressure sensor 6101 detects the pressure in the working chamber of the artificial heart 101, and gives a signal (voltage) indicating this to the pumping controller 4201.

FIG. 2 shows a fluid pump 1 driven by a linear motor.
2 shows an enlarged vertical section, and FIG. 3 shows a section taken along the line IIB-IIB in FIG. Referring to these drawings, the end member 14 in which the fluid output port 15 is formed, together with the outer case 16,
It is fixed to the ring 13. A right end of a generally cylindrical bellows 19 is fixed to the ring 13. Bellose 1
A partition member 17 is fixed to the left end of 9. The end member 14, the bellows 19, and the partition member 17 define a fluid space 50 communicating with the output port 15.

The right end of the rod 18 is fixed to the center of the partition member 17. By driving this rod 18 forward / backward to the right / left, the fluid space 50 is contracted / expanded, the silicone oil in the fluid space 50 is supplied from the output port 15 to the working chamber 3 of the artificial heart 1, and Silicone oil in the working chamber 3 is sucked into the fluid space 50 through the output port 15.

An end plate 51p of a linear motor is fixed to the left end wall of the outer case 16, and two magnetic support plates 2 facing each other with the center point of the end plate 51p interposed therebetween.
The right ends of 1 and 22 are fixed to a magnetic end plate 51p. The left ends of the support plates 21 and 22 are fixed to another end plate 52p made of a magnetic material. Support plates 21, 22 with first and second bearings 20A and 20B between them
Supported on these bearings 20A and 20B
Is penetrated by the rod 18. A permanent magnet plate 25 is provided on the upper surface of the support plate 21, and a permanent magnet plate 2 is provided on the lower surface of the support plate 22.
6 is fixed.

A magnetic support plate 23 is fixed to the upper ends of the end plates 51p and 52p, and a magnetic support plate 24 is fixed to the lower ends of the end plates 51p and 52p. A magnet plate 27 and a permanent magnet plate 28 are fixed to the upper surface of the support plate 24. Between the permanent magnet plates 25 and 27, and between the permanent magnet plates 26 and 28, there is a space through which the coil bobbin 29 passes, and the coil bobbin 29 is arranged therein. This coil bobbin 29 is attached to the permanent magnet plate 2
5, the support plate 21, the rod 18, the support plate 22, and the permanent magnet plate 26 penetrate. An electric coil 30 is wound around the coil bobbin 29. Also, this coil bobbin 2
As shown in FIG. 3, an arm 29A passing through a gap between the support plates 21 and 22 is integrated with the armature 9, and the rod 18 is fixed to the arm 29A. Therefore, by moving the coil bobbin 29 to the right and left, the rod 18
Moves to the right and left, the partition member 17 is driven to the left and right, the fluid space 50 is contracted / expanded, and the silicone oil in the fluid space 50 is supplied to the working chamber 3 of the artificial heart 1 from the output port 15 and also actuated. Silicone oil in the chamber 3 is sucked into the fluid space 50 through the output port 15.

The permanent magnet plate 25 is uniformly magnetized so that the upper surface becomes the N pole and the lower surface becomes the S pole, and the permanent magnet plate 27 has the upper surface as the N pole and the lower surface as the S pole. In the space between the permanent magnet plates 25 and 27, that is, the space in which the electric coil 30 moves, the permanent magnet plate 25 side is the N pole and the permanent magnet plate 27 side is the S pole. of,
A substantially uniform magnetic field (parallel magnetic field) is formed. The magnetic flux of the upper surface of the permanent magnet plate 25-the lower surface of the permanent magnet plate 27-the upper surface of the permanent magnet plate 27-the support plates 23-the end plates 51 and 52-the support plate 21-the lower surface of the permanent magnet plate 25-the permanent magnet plate 25. It flows on the path called the upper surface.

The permanent magnet plate 26 is uniformly magnetized so that the lower surface becomes the N pole and the upper surface becomes the S pole, and the permanent magnet plate 28 has the upper surface as the S pole and the lower surface as the N pole. In the space between the permanent magnet plates 26 and 28, that is, in the space where the electric coil 30 moves, the permanent magnet plate 26 side is the N pole and the permanent magnet plate 28 side is the S pole. of,
A substantially uniform magnetic field is formed. The magnetic flux is the lower surface of the permanent magnet plate 26-the upper surface of the permanent magnet plate 28-the permanent magnet plate 28.
Lower surface-support plate 24-end plates 51p, 52p-support plate 22
-The upper surface of the permanent magnet plate 26-The lower surface of the permanent magnet plate 26. Now, when a current (forward direction current) flowing in the electric coil 30 in a portion between the permanent magnets 25 and 27 in the direction from the front side to the back side of the paper surface of FIG. 2 flows, the electric coil is caused by Fleming's left-hand rule. 30 permanent magnets 25
The electromagnetic force directed to the right acts on the portion between −27 and the portion between the permanent magnets 26 and 28, and the electric coil 30, that is, the coil bobbin 29 moves to the right in FIG.
8 is driven to the right (ejection). When a current in the opposite direction to the above (current in the opposite direction) flows through the electric coil 30, the coil bobbin 29 moves leftward and the rod 18 is driven leftward (inhalation).

The electric coil 30 is connected to the motor driver 31. FIG. 4 shows the configurations of the motor driver 31 and the pumping controller 42 that controls the energization of the motor driver 31. Referring to FIG. 4, one end of the electric coil 30 of the linear motor is connected to the switching transistor Tr1.
It is connected to the positive power supply line Psp or the negative power supply line Psn through p or Tr2n, and the other end of the electric coil is connected to the positive power supply line Psp or the negative power supply line Psn through the switching transistor Tr1n or Tr2p. A zener diode 32 for short-circuiting a surge voltage is connected in parallel to the electric coil 30. The positive power supply line Psp is connected to the + 24V power supply terminal by the relay 35, and the negative power supply line Psn is connected to the equipment ground. The coil of the relay 35 is connected to the relay driver (amplifier) 34.

When the output Q of the R / S flip-flop 52 of the pumping controller 42 becomes the high level H, the light emitting diode of the photocoupler 32p lights up, the switching transistors Tr1p and Tr2p become conductive (turn on), and the electric coil 30 is connected. A current flows in the positive direction, the electric coil 30 moves to the right in FIG. 2, and the silicone oil in the fluid space 50 is discharged from the output port 15 (positive pressure period: discharge period). Output Q of R / S flip-flop 52
When H is H, it is inverted by the inverter 33 and applied to the photocoupler 32. Therefore, the light emitting diode of the photocoupler 32 does not light up, and the switching transistors Tr1n and Tr2n are non-conductive (OFF).

When the output Q of the R / S flip-flop 52 of the pumping controller 42 goes to a high level L, the output of the inverter 33 goes to H, so the photocoupler 32n.
The light emitting diode of is turned on, the switching transistors Tr1n and Tr2n are turned on, a reverse current flows in the electric coil 30, the electric coil 30 moves to the right in FIG. Silicone oil is sucked (negative pressure period: suction period).

The switching signal of the relay 35 is the CPU
43 provides to the motor driver 31. The pumping controller 42 includes the CPU 43 and the operation / display board 4.
Including 4. Although not shown on the operation / display board 44,
A large number of key switches for instructing adjustment of various drive parameters, a key switch for instructing start and a key switch for instructing stop, and various indicators for displaying the value of each parameter at that time are provided. The adjustable parameters include the force (positive and reverse energizing current values) for driving the driving liquid (silicone oil) applied to the artificial heart 1, the period for applying the positive pressure, and the pulsation cycle. Further, in this example, the timing of applying the positive pressure and the timing of applying the negative pressure to the artificial heart 1 are generated inside the CPU 43 (internal synchronization) or a synchronization signal applied from the outside (“in FIG. 4”). It is possible to switch whether to synchronize with "external synchronization").

In this embodiment, the electric current value of the electric coil 30 is such that the electric current is applied to the electric coil 30 in the forward direction during the period Tp (64 μsec) and the electric current is applied to the electric coil 30 in the reverse direction during the period T-Tp. Then, it is determined by Tp / T. For example, as shown in FIG.
When the output Q of H is switched to H / L in the T cycle and the H section Tp is shortened sequentially, the voltage of +24 V (forward conduction voltage) when the output Q is H and the electric coil 30 is − when the output Q is L. Two
A voltage of 4 V (reverse conduction voltage) is applied, and the time-sequential averaging (smoothing) voltage sequentially changes from plus to minus. A current corresponding to this voltage flows through the electric coil 30. That is, in this embodiment, the absolute value and the polarity of the energizing current value of the electric coil 30 are determined by a kind of duty control.

The cycle T of this duty control is
This is 64 μsec, which is a carry pulse of the cyclic counter 51 that generates a carry pulse when the count value reaches 256, automatically returns to the count value 0, and counts up again, that is, the carry pulse of the oscillator 50 of 4 MHz. 0.25μse generated by oscillator 50
A pulse generated when counting 256 pulses of the c cycle (cycle T = 0.25 μsec × 256 = 64 μs
ec), by setting the flip-flop 52. The forward direction energization section Tp during the period T is T
The data Vo indicating p is given to the preset counter 49,
When the preset counter 49 loads the data Vo in response to the carry pulse of the counter 50 and then counts down the pulse generated by the oscillator 50, when the count data becomes zero (completion of counting Vo). This is defined by generating a borrow pulse and resetting the flip-flop 52 with this borrow pulse. Therefore, when the CPU 43 changes the Vo data given to the preset data input terminal of the preset counter 49 via the input / output port 45, the length of the forward direction energization section Tp in the cycle T, that is, the duty changes.

The beat cycle Tc is determined by an externally applied sync signal (external sync mode), or the beat cycle data Tc (m is input from the operation / display board 44.
Sec unit) (internal synchronization mode). In the internal synchronization mode, the CPU 43 executes an interrupt process in response to a time-over signal (carry pulse) generated by the timer 53 every time 1 msec elapses. When the number of arrivals is counted and the count value becomes Tc, the preset counter 4
9 preset data Vo to drive voltage Vp in the discharge period
(8-bit data indicating Tp) is switched to, and the count value is initialized (cleared). In the external synchronization mode, switching is performed in this way when a synchronization signal comes from the outside.

The ejection period Ts is determined by a synchronization signal given from the outside (external synchronization mode), or the ejection period data Ts input from the operation / display board 44.
(Internal synchronization mode)
De). In the internal synchronization mode, the CPU 43 is 1 m
An interrupt process is executed in response to a time-over signal (carry pulse) generated by the timer 53 each time a time period of sec elapses. In this interrupt process, the number of times the time-over signal arrives is counted, and the count value is Ts. Then, the CPU 43
Therefore, the preset data Vo is set to 1 by the above-mentioned interrupt processing.
Update to a smaller value (decrease duty step by step). In the external synchronization mode, switching is performed in this way when a synchronization signal comes from the outside. As a result, the average voltage applied to the electric coil 30 exhibits the change shown in FIG.
This is repeated in the Tc cycle.

As shown in FIG. 8, the voltage (instantaneous voltage) applied to the electric coil 30 is + 24V to -24V, and 256 steps (maximum value of 8-bit data) are allocated between them, so one step is , 48/256 V, and the preset data Vo is updated to a value smaller by 1 in the above-described interrupt processing, so the voltage drop speed at this time is ΔT
= (48/256) × 1000 V / sec. When the preset data Vo becomes equal to or lower than the specified value Vn of the minimum voltage of the suction period (absolute value, the maximum voltage of the suction period) pre-input on the operation / display board 44, the preset data Vo is updated (reduced) there. ) Stop.

Even if the minimum voltage is less than the specified value Vn,
The pressure determination circuit 480 determines that the pressure detected by the pressure sensor 61 is the first
When it falls below the set value a (absolute value exceeds the first set value a) (the negative pressure becomes strong), the voltage decrease speed is reduced to ½, that is, (1/2) · ΔT = (48/256) × ( 1/2) x 100
When it is changed to 0 V / sec and the detected pressure of the pressure sensor 61 falls below the second set value b (absolute value exceeds the second set value b) (negative pressure becomes strong), the voltage drop is stopped. To do. That is, the suction pressure increase is stopped. On the other hand, the level of the signal h is read at a cycle of 1 msec, and if it is a high level H, the content of the count register ADC is incremented by 1,
When the number of readings reaches 100 (100 msec) (100 msec = initial period of suction start) and the value of the register ADC is 50 or less, the pressure sensor 61-the pressure determination circuit 4
80-The signal line and the electric circuit element of the CPU 43 are regarded as normal, but if they are 51 or more, they are regarded as abnormal (including mixing of noise), and in this case, in order to prevent the artificial heart from stopping, As in the case of normal negative pressure, the voltage decrease rate is ΔT = (48/256) × 1000V /
Let be sec.

Next, it is judged whether or not the pressure detected by the pressure sensor 61 is equal to or more than the first set value a and the second set value b, and this judgment signal line h is set to the pressure sensor system. The pressure determination circuit 480 that gives the monitor signal f for detecting an abnormality will be described. It should be noted that the signals of the respective parts of the circuit 480 are shown in FIG. 9, so refer to FIG. 9 in addition to FIG. The pressure detected by the pressure sensor 61 is less than the first set pressure a designated by the first potentiometer (since the suction period,
The detected pressure is negative pressure. Expressed by the absolute value of the pressure, when the detected pressure exceeds the set pressure), the output c of the first comparator 46a is inverted from the low level L to H. When the detected pressure of the sensor 61 becomes less than the second set pressure b (b <a) designated by the second potentiometer, the output d of the second comparator 46b is inverted from L to H. Therefore, when the detected pressure is decreasing, the output of the first comparator 46a first becomes H, and then the second comparator 46a.
The output of b becomes H. The output d of the second comparator 46b is sent to the signal line h through the ohage 47d and given to the microprocessor 43 through the input / output port 45, and is also inverted by the inverter 47a. d '
Is output from the first comparator 46a together with the AND gate 47.
given to b.

The output e of the AND gate 47b is H when the detected pressure is less than the first set pressure a and not less than the second set pressure b.
This output e and the oscillator 48 have a duty ratio of 50%.
00 Hz pulse f (2 msec cycle)
To 47c. Output g of AND gate 47c
Is L continuously when the pressure detected by the pressure sensor 61 is equal to or higher than the first set pressure a, but becomes the pulse f when the detected pressure is lower than the first set pressure a and equal to or higher than the second set pressure b. That is, when the detected pressure is between the first set pressure a and the second set pressure b, the pulse f is output. Output g of AND gate 47c and second
The output d of the comparator 46b is applied to the age gate 47d. The output h of the o'clock 47d is continuously L when the pressure detected by the pressure sensor 61 is equal to or higher than the first set pressure a, but becomes the pulse f when the pressure is less than the first set pressure a and equal to or more than the second set pressure b. , When the pressure is less than the second set pressure b, it continuously becomes H. This output h is given to the microprocessor 43 via the input / output port 45.

The motor driver 3101 shown in FIG.
Is the same as the configuration of the motor driver 31, the configuration of the pumping controller 4201 is the same as the configuration of the pumping controller 42, and the configuration of the pressure determination circuit 4801 is the same as the configuration of the pressure determination circuit 480. ..

FIG. 5 shows an outline of the control operation of the CPU 43 shown in FIG. When the power is turned on (step 1: the word step is omitted hereinafter in parentheses), the CPU 43 performs initialization (2). That is, the contents of the internal memory are cleared, the output signal level during standby is output to the output port, and the preset initial value (standard value) is set in the area (register) where various parameter values of the internal memory are written. (Write)

In this initialization (2), the voltage data Vp applied to the electric coil 30 during the discharge period (data indicating the Tp section length for applying the average voltage Vp to the electric coil 30; the unit is generated by the oscillator 50). Pulse period 0.2
5 μsec, the standard value Vps is written in the register Vp for writing the 8-bit data indicating the count number of the pulse, and the ejection period data Ts (unit is 1 msec, the timer 53 time-out) in the case of the internal synchronous drive. Number of times)
Is written in the register Ts for writing the standard value Tss, and the standard value Vn is written in the register Vn for writing the voltage data Vn applied to the electric coil 30 during the inhalation period (8-bit data similar to the above Vp).
A standard value Tcs is written into a register Tc for writing beat cycle data Tc (unit is 1 msec, the number of times the timer 53 times out) in the case of internal synchronous drive.

Upon completion of the initialization (2), the CPU 43 reads the input operation of various key switches provided on the operation board 42 and changes the set value (contents of the various registers) corresponding to the input, and various kinds at that time. Display output processing of the set values of the parameters to the operation board 42 is performed (4).

When the start key switch of the operation board 42 is operated, the CPU 43 permits the interruption (7), energizes the relay 35, and the plus power source line Ps.
p is connected to the + 24V power supply terminal (8A), and Vo = Vp is given to the preset counter 49 (8B). As a result, the voltage Vp in the discharge period is applied to the electric coil 30, and a forward current flows through the electric coil 30 (the fluid space 5 in FIG. 2).
0 is reduced and a high voltage is applied to the artificial heart 1).

When the timer 53 generates a time-out signal (every time elapses of 1 msec) by permitting the interrupt (7), the CPU 43 executes the interrupt process (20) shown in FIG. After that, the CPU 43 waits for a new input on the operation / display board 44 in the main routine (FIG. 5) (9). When there is a new input, when it is an operation parameter, the contents of the register storing it is updated to the input of this time and the display is changed to that (10, 11). When there is a stop input,
The relay 35 is de-energized (the power of the motor driver 31 is thereby turned off and the linear motor 12 is stopped) (12, 13), and interruption is prohibited (14). By prohibiting this interrupt, the CPU 43 does not execute the interrupt processing of FIG. Then, the CPU 43 waits for the start input again (4,5).

Referring to the interrupt processing (20) shown in FIG. 6,
The pumping control of the CPU 43 will be described. In the interrupt process (20), the timer 53 sends the time-out signal 1 m.
Since it is generated in a sec cycle and executed in response to this signal, it is executed in a 1 msec cycle, and the output h of the pressure determination circuit 480 indicates that the pressure detected by the pressure sensor 61 is the first set value a or more ( When the detected pressure is less than the first set value a and greater than or equal to the second set value b, the output pulse f of the oscillator 48 becomes 1 when the absolute value is a or less).
Alternate repetition of H for msec and L for 1 msec results in 1
The level of output h is 100 times (100 ms
ec) When reading, the output h = H is read 50 times, and when the detected pressure becomes less than the second set value b, the output h of the circuit 480 becomes continuous H and the level of the output h becomes 100 at 1 msec cycle. Note that the output h = H is read 100 times when read 100 times (100 msec).
When the output h = H is read 51 times or more out of 100 readings, this means that (A) the detected pressure is less than the first set value a as well as the second set value during 100 msec. has also been less than b, and / or
(B) A signal abnormality (noise or the like) on the signal line (h) of the sensor 61 to the input / output port 45 or a circuit defect of the sensor 61 to the input / output port 45 is considered. The latter (B) is an abnormality of the pressure sensor system. By the way, in the former (A), the pressure sensor 61 is interpreted as normal, but during the first 100 msec at the beginning of the suction period (Tc-Ts) from the discharge period Ts, the pressure immediately before is 100%, so the pressure still remains. It is high and the detected pressure cannot be less than the second set value b. Therefore, the above (A) should be regarded as an abnormality of the pressure sensor system. After all, 10 during the 100 msec
If the output h = H is read 51 times or more in 0 readings, it means that the pressure sensor system is abnormal.

By the way, the interrupt processing (20) shown in FIG.
Is executed when the internal synchronization mode is specified. When the external synchronization mode is specified, when the external synchronization signal (discharge period synchronization signal, suction period synchronization signal) arrives while waiting for the operation board input in the main routine (FIG. 5) (9), the arrival is indicated. Write a signal (discharge period synchronization flag / suction period synchronization flag) to a register and another register (suction period synchronization flag / discharge period synchronization flag)
Is cleared, and in the interrupt process, steps 21A and 2 in FIG.
Instead of 1B and 22, referring to the contents of the register, if there is a signal indicating the arrival of the ejection period synchronization signal,
When the signal indicating the arrival of the suction period synchronization signal is present, the process proceeds to step 30 described later, and the process proceeds to “suction pressure control” 27 described later. In other respects, the control operations in the internal synchronization mode and the external synchronization mode are the same.

(1) Control of the ejection period of the first beat in response to the first start input (5) after the power is turned on (1): When the CPU 43 proceeds to the interrupt process (20) in the internal synchronous mode, the CPU 43 counts the number of times. Increment the contents of register n by 1 (21
A), it is checked whether the number-of-times count value n is greater than or equal to the beat cycle Tc (21B). If not, it is checked whether the number-of-times count value n is equal to or greater than the ejection period Ts (2).
2). If not, the process returns to the main routine (Fig. 4) (return). In this way, every time the process proceeds to the interrupt process (20), steps 21A-21B-225-return are executed. The content n of the register n is the elapsed time within one beat (ms
ec unit). During this time, the preset counter 49
Is applied with Vo = Vp (8B), and the discharge period voltage Vp is applied to the electric coil 30 by the operation of the counter 51, the flip-flop 52, and the preset counter 49 described above, and the electric coil 30 is fed in the forward direction. A current flows and the rod 18 is driven to the right in FIG. 2 (the fluid space 50 in FIG. 2 is reduced and high pressure is applied to the artificial heart 1: FIG. 1).
0 Ts section).

When n ≧ Ts (after the start instruction, the ejection period of the first beat ends), the control proceeds to the next suction period control (21A-21B-22-27 in FIG. 6).

(2) First start input (5) after power-on (1)
Control of suction period of the first beat in response to: The content of the register n is Ts or more, and the content of the register ADC is 0. 21A-21B-22-27 when proceeding to the interrupt processing (20)
After that, the process advances to the suction control 27.

The contents of the suction control 27 are shown in FIG. In the suction control 27, first, the content n'of the register n'for counting the elapsed time of the suction period is incremented by 1 (4
0), the content n ′ of the register n is less than 100 (less than 100 msec after entering the suction period), 100 (just 100 msec), or more than 100 (100).
It is checked whether it exceeds msec) (41, 44).

If it is less than 100 (just after entering the suction period), the level of the signal h is checked (42A).
When the detected pressure is equal to or higher than the first set value a, the signal h = L,
When the value is less than the first set value a and is greater than or equal to the first set value b, the signal h = pulse f, H of 1 msec and L of 1 msec appear alternately, and the suction control 27 is executed in a cycle of 1 msec. In step 42A, the probability of reading h = H is 1/2, and if it is less than the second set value b, the signal h = H.
Therefore, the probability of reading h = H is 1. Then, if it is H, the content of the count register ADC is incremented by 1 (42B), and after checking 43, the signal h is referenced again (50). If the signal h is H, the interrupt process is terminated and the main routine is terminated. -Return to Chin (Figure 5). That is, the energization duty (Vo) for reducing the pressure (negative pressure absolute value) (increasing the negative pressure) is not updated (the increase of the suction negative pressure absolute value is stopped). When the signal h is L in step 50, it is checked whether the voltage is equal to or lower than the minimum voltage Vn in the suction period (55). When V ₀ is larger than Vn (the coil voltage is not lowered to the minimum voltage Vn in the suction period), the data V ₀ is updated to a _value that is one smaller and updated and output to the preset counter 49 (56). Thus, when the detected pressure is equal to or higher than the first set value a, the energization duty is Δ.
Although it is updated at the speed of T, the probability of reading h = H is 1/2 when the detected pressure is less than the first set value a and not less than the second set value b, so the energization duty is (1/2).・ Updated at the speed of ΔT. When the detected pressure is less than the second set value b, h =
Since the probability of reading H is 1, the updating of the energization duty is stopped and the increase in negative pressure is stopped.

In this way, the suction period (Tc-Ts)
During less than 100 msec after entering, the interrupting process (20, 27) is performed while the detected pressure is the first set value a or more (negative pressure absolute value is a or less) and the coil voltage is not reduced to Vn. )
Then, steps 21A-21B-22-27 (40-41-42A-43-50-55-
56) is executed, and the suction pressure is gradually lowered at the speed of ΔT (the absolute value of the negative pressure is increased). The above is the suction period (T
It is a control for less than 100 msec after entering c-Ts).

When the content n'of the count register n'becomes 100, that is, when 100 msec has elapsed just after entering the suction period (Tc-Ts), it is checked whether the content ADC of the count register ADC is 51 or more. Yes (40-41-44-45). During this 100 msec, pressure sensor 61
When the detected pressure of is greater than or equal to the first set value a (absolute value is less than or equal to a), the signal h = L and the ADC is 0.
When the value is less than the set value a and is greater than or equal to the second set value b, the signal H
= With pulse f, this is alternately switched to H for 1 msec and L for the next 1 msec, and interrupt processing 20 is executed at 1 msec cycles. Therefore, check this signal h at 1 msec cycles, and ADC when h = H. Is incremented by 1 (42A, 42A
Since B), the ADC is 50 or less. ADC ≧ 51,
H other than the output f, that is, the pressure detected by the pressure sensor 61 is less than the second set value b, or there is some abnormality or noise in the circuit or signal path from the pressure sensor 61 to the signal h line. Means that. Within 100 msec after entering the suction period, the discharge period is before that period and the pressure is substantially the highest value, so the pressure is high and the pressure detected by the pressure sensor 61 is less than the second set value b ( Since absolute value does not exceed b), ADC ≧ 51
Means that some abnormality or noise is mixed in the circuit or signal path from the pressure sensor 61 to the signal h line, that is, the abnormality of the pressure sensor system.

Therefore, if the ADC is 51 or more, the data H indicating the abnormality is written in the abnormality data register ADF (46), and the abnormality information is output to the operation / display board 44,
An abnormality is displayed on the operation / display board 44 and the buzzer is intermittently energized (47). When the ADC is 50 or less, the abnormal data register ADF is cleared (synonymous with L writing) (48), and an abnormal output clear signal is given to the operation / display board 44 (49). As a result, when the error display and buzzer ringing were made by then,
The error display disappears and the buzzer stops beeping.

Now, the content n'of the count register n'is
When it is 100 or more (100 msec or more has passed from the start of the suction period), in the suction pressure control 27, steps 40-41-44-43
Then, it is checked whether or not the data H indicating the abnormality of the pressure sensor system exists in the register ADF (43), and if it exists, the pressure sensor 61, the pressure determination circuit 480 and the signal line from the circuit 480 to the CPU 43. Since there is some abnormality in h and the output signal of the circuit 480 is unreliable, in order to prevent pace down or stop of the artificial heart, the routine proceeds from step 43 to step 55, where the output data V to the preset counter 49 is V. _It is checked whether ₀ is equal to or lower than the minimum voltage Vn in the suction period (55). When V ₀ is larger than Vn (the coil voltage is not lowered to the minimum voltage Vn in the suction period), the data V ₀ is updated to a _value that is one smaller and updated and output to the preset counter 49 (56). That is, when it is determined that the pressure sensor system is abnormal, the update rate of the energization duty is set to ΔT until it becomes the minimum voltage Vn in the suction period, as in the steady state. That is, the voltage (average voltage) applied to the electric coil 30 is reduced at a speed of ΔT until the end of the suction period (passage of Tc). However, when it is reduced to Vn, the reduction stops there.

Abnormal data H is not in the register ADF (A
In the suction period when 100 msec has elapsed when DF = L),
After step 43, it is checked whether the signal h is H (5
0). When the detected pressure is equal to or higher than the first set value a, the signal h = L, and when the detected pressure is less than the first set value a and equal to or more than the first set value b, the signal h = pulse f and H of 1 msec and L of 1 msec.
Alternately appear and the suction control 27 is executed at a cycle of 1 msec. Therefore, the probability that h = H is read in step 42A of the suction control 27 is 1/2, and if it is less than the second set value b, the signal h continues. Is H, and the probability of reading h = H is 1.
Then, when the signal h is H, the interrupt process is terminated and the process returns to the main routine (FIG. 5). That is, the energization duty for decreasing the pressure (absolute value of negative pressure) (increasing the negative pressure).
The tee (Vo) is not updated (the increase of the suction negative pressure absolute value is stopped). When the signal h is L in step 50, it is checked whether the voltage is equal to or lower than the minimum voltage Vn in the suction period (55). When V ₀ is larger than Vn (the coil voltage is not lowered to the minimum voltage Vn in the suction period), the data V ₀ is updated to a _value that is one smaller and updated and output to the preset counter 49 (56).

As a result, the abnormal data H is transferred to the register AD.
If it is not in F (ADF = L / pressure sensor system is normal), the energization duty is updated at a speed of ΔT when the detected pressure is equal to or higher than the first set value a, but the detected pressure is the first set value. a
Less than Second setting value b or more, the probability of reading h = H is 1
Since it is / 2, the energization duty is updated at a rate of (1/2) · ΔT, and the rate of increasing the negative pressure is reduced to 1/2 in order to wait for pressure recovery (blood collection to the living heart). Even if the pressure is not recovered and the detected pressure becomes less than the second set value, the probability that h = H will be read continuously and h = H will be 1 will be 1. The updating of the energizing duty will stop, and the living heart will be released by the cannula. The strong suction of is avoided.

Referring now to FIG. 100 mse after the end of the discharge period Ts and the start of the inhalation period (Tc-Ts)
During c, "43 count-up timing" in FIG.
As shown in, when the detected pressure is equal to or higher than the first set value a, AD
C is not counted up, but the detected pressure is the first set value a
Less than 2nd setting value b or more AD in 2msec cycle
C is incremented by 1, and when the detected pressure is less than the second set value b, the ADC is incremented by 1 in a cycle of 1 msec. In FIG. 9, "output 53" is a 1 msec cycle, "48 output f" is a 2 msec cycle, and the duty is 50%. 100m after entering inhalation period
In the interval of sec, as shown in “43, timing of lowering Vo” in FIG. 9, when the detected pressure is equal to or higher than the first set value a, Vo is lowered by one step in a cycle of 1 msec.
Although the voltage Vo decreases at the speed of T, the detected pressure is the first set value a.
When the value is less than the second set value b, the voltage is decreased by one step in a cycle of 2 msec, which causes the voltage Vo at a speed of (1/2) · ΔT.
Goes down. When the detected pressure is less than the second set value b, the voltage V
Since o is not updated, the drop in voltage Vo stops.

10 after entering the inhalation period (Tc-Ts)
After the lapse of 0 msec, if the content of the register ADF is H indicating an abnormality of the pressure sensor system, regardless of the detected pressure, 1
By decreasing Vo by one step in the msec cycle, the voltage Vo decreases at the speed of ΔT. If the content of the register ADF is L indicating that the pressure sensor system is normal, “43 of FIG.
As shown in "Timing to lower Vo", the detected pressure is the first
When the value is equal to or higher than the set value a, Vo is decreased by one step in a cycle of 1 msec, whereby the voltage Vo is reduced at a speed of ΔT, but when the detected pressure is less than the first set value a and equal to or more than the second set value b, 2
It is lowered by 1 step every msec cycle, which results in (1/2) ・ Δ
The voltage Vo decreases at the speed of T. When the detected pressure is less than the second set value b, the voltage Vo is not updated, so that the decrease of the voltage Vo is stopped.

When the content of the number count register n becomes Tc or more (the suction period ends), the number count register n is cleared (21A-21B-30 in FIG. 6) and the preset data V ₀ to the preset counter 49 is set. Is updated to Vp that specifies the coil voltage in the discharge period (32), the contents of the register n ′ are also cleared (32), and the register ADC
Clear the contents of (33).

(3) Control of ejection period after the second beat: above
Same as (1).

(4) Control of suction period after the second beat: above
Same as (2).

By the above-described pumping control operation, the coil applied voltage V ₀ is basically in the discharge period (Ts in FIG. 10).
(This is the data showing Tp in FIG. 8.
The average voltage of the relationship shown in FIG. 8 is applied to the coil 30) is constant at Vp, but when the discharge period is switched to the suction period, all the electric circuits and signal lines of the pressure sensors 61 to 43 are normal. If the suction negative pressure does not become excessive (absolute value exceeds a), the coil applied voltage V
₀ is reduced by 1 step every 1 msec, and the voltage gradually decreases from positive to 0 at a speed of ΔT = (48/256) × 1000 V / sec, and then gradually increases in the negative direction (negative direction current Gradually increase). Then, when V ₀ is changed to Vn (the designated value of the suction voltage), the change of the voltage is stopped there (5
5,56).

By the way, the first 100 msec in the suction period (while the voltage is decreased from the positive side to the negative side and then increased to the negative side, that is, while the suction pressure is increasing: Tc-Ts in FIG. 10). During this period, the pressure sensor system is judged to be abnormal, and if it is judged to be abnormal, H is written in the register ADF and an alarm is issued (46, 47).

During the remaining period (Tc-Ts-100 msec) of the suction period after the end of the determination process, if the register ADF has H indicating an abnormality of the pressure sensor system, the average applied to the coil 30 is averaged. Until the voltage Vo drops to the set value Vn, it is lowered at a falling rate of ΔT = (48/256) × 1000 V / sec. That is, since the pressure sensor 61 and the like cannot be relied on, the pressure is reduced at a speed of ΔT as in the steady state in order to prevent a decrease or stop of the pumping speed. When the content of the register ADF is L, the pressure sensor system is considered to be normal, so that the pressure detected by the pressure sensor 61 is
In order to prevent the excessive suction (strong suction) of the living tissue by the cannula, when the detected pressure becomes less than the first set value a (the absolute value of the negative pressure exceeds a), the average voltage Vo applied to the electric coil 30 thereat. The descent rate of (1/2) · ΔT = (48/256) ×
Reduce to 1000V / sec. Due to this decrease, blood collection proceeds in the living heart, and when the detected pressure rises, the falling rate returns to ΔT. When the detected pressure becomes less than the second set value b (the absolute value of the negative pressure exceeds b) despite the decrease to (1/2) · ΔT, the average voltage Vo applied to the electric coil 30 thereat.
Stop descent. Therefore, the living heart is not forcibly pulled by the cannula 7, and the probability of damaging the living heart is reduced.

[0070]

As described above, according to the present invention, it is possible to prevent the pumping from being stopped due to the abnormality of the pressure sensor system.

[Brief description of drawings]

FIG. 1 is a side view showing an appearance of an embodiment common to each invention of the present application.

FIG. 2 is an enlarged vertical sectional view of the liquid pump 12 shown in FIG.

FIG. 3 is a sectional view taken along line IIB-IIB of FIG.

FIG. 4 is an electric circuit diagram showing configurations of a motor driver 31 and a pumping controller 42 shown in FIG.

5 is a flowchart showing an outline of a control operation of the microprocessor 43 shown in FIG.

6 is a flowchart showing an interrupt processing operation of the microprocessor 43 shown in FIG.

FIG. 7 is a flowchart showing the contents of “suction pressure control” (27) shown in FIG.

8 is an output Q of the flip-flop 52 shown in FIG.
3 is a time chart showing the relationship between the voltage and the voltage applied to the electric coil 30 of the linear motor 12.

9 is a time chart showing an electric signal of each circuit portion of the pressure determination circuit 480 shown in FIG.

10 is a time chart showing a time series change of an average voltage applied to the electric coil 30 by energization control of the microprocessor 43 shown in FIG. 3, where Tc is one beat period (one cycle of one reciprocating motion). Yes, Ts is the ejection period.

[Explanation of symbols]

1,101: Artificial heart 2: Diaphragm 3: Working chamber 4: Inner space 5,6: Reverse valve 7,8: Cannula 9,901: Tube 12,1201: Liquid pump 13: Ring 14: End member 15: Output port 16: Outside Case 17: Partition member 18: Rod 19: Bellows 20A, 20B: Bearing 21,22,23,24: Support plate 25,26,27,2
8: Permanent magnet plate 29: Coil bobbin 29A: Arm 30: Electric coil 31: Motor driver 34: Relay driver 35: Relay 42,4201: Pumping controller 43: Microprocessor 44: Operation / display board 50: Fluid space 51p, 52p: End plate 61,6101: Pressure sensor 480,4801: Pressure judgment circuit

Claims (4)

[Claims] 1. A reciprocating member which communicates with a fluid output port to reduce / enlarge a fluid space in which an incompressible liquid is stored, an electric coil for reciprocating the reciprocating member, and an electric coil of the electric coil. A liquid pump driven by a linear motor, comprising magnetic field generating means for applying a magnetic field in a direction orthogonal to the extending direction to the electric coil and generating a forward / backward moving force corresponding to the forward / reverse energization direction in the electric coil; A pressure detecting means for detecting the pressure of the fluid output port or a flow path communicating with the fluid output port; a sensor abnormality detecting means for detecting an abnormality of a detection signal of the pressure detecting means; an energizing means for applying a forward / reverse current to the electric coil; When the pressure detected by the pressure detecting means is equal to or higher than the set pressure in the energization for driving the reciprocating member in the direction of expanding the fluid space communicating with the fluid output port, the communication is performed at a predetermined change rate. The current flowing through the electric coil is sequentially changed through the electric means in a direction to increase the expansion, and when the pressure detected by the pressure detecting means is less than the set pressure, the change rate is reduced, and the sensor abnormality detecting means A pumping device comprising: a current value control means, which sequentially changes the energizing current value at a rate of change higher than the rate of change when the pressure is less than the set pressure when an abnormality of the detection signal is detected. 2. A reciprocating member that communicates with a fluid output port and reduces / enlarges a fluid space containing an incompressible liquid, an electric coil for reciprocating the reciprocating member, and an electric coil of the electric coil. A liquid pump driven by a linear motor, comprising magnetic field generating means for applying a magnetic field in a direction orthogonal to the extending direction to the electric coil and generating a forward / backward moving force corresponding to the forward / reverse energization direction in the electric coil; Pressure detecting means for detecting the pressure of the fluid output port or the flow path communicating therewith; energizing means for applying forward / reverse current to the electric coil; generating a signal indicating this when the pressure detected by the pressure detecting means is less than a set pressure Monitor means for applying a level change similar to that of the signal indicating less than the preset pressure to a signal line for transmitting a signal generated by the comparator in a preset cycle; During energization for driving the reciprocating member in the direction of expanding the fluid space communicating with the body output port, the signal level appearing on the signal line is checked at a predetermined cycle for a set time from the beginning of the body, and the signal level is less than the set pressure. And a fluid space communicating with the fluid output port, which detects the number of signal levels indicating the signal level and generates sensor abnormality information when the number of times during the set time is greater than or equal to a set value. When energizing the reciprocating member in the direction of enlarging, when the pressure detected by the pressure detecting means is equal to or higher than a set pressure, the energizing current value of the electric coil is enlarged through the energizing means at a predetermined rate of change. Is sequentially changed in a direction of increasing the pressure, the rate of change is reduced when the pressure detected by the pressure detection means is less than a set pressure, and the pressure signal abnormality detection means generates sensor abnormality information. Sequentially changing the electric current value at a higher rate of change than the change rate of time of less than constant pressure, current value control means; pumping device comprising a. 3. A reciprocating member communicating with a fluid output port for reducing / enlarging a fluid space containing an incompressible liquid, an electric coil for reciprocating the reciprocating member, and an electric coil of the electric coil. A liquid pump driven by a linear motor, comprising magnetic field generating means for applying a magnetic field in a direction orthogonal to the extending direction to the electric coil and generating a forward / backward moving force corresponding to the forward / reverse energization direction in the electric coil; Pressure detecting means for detecting the pressure of the fluid output port or the flow path communicating therewith; energizing means for applying forward / reverse current to the electric coil; this is shown when the pressure detected by the pressure detecting means is less than the first set pressure a. First comparing means for generating a first signal on a signal line; second comparing means for generating a second signal indicating the pressure on the signal line when the pressure detected by the pressure detecting means is less than a second set pressure b; Monitor signal generating means for applying the same level change to the signal line as the first and second signals indicating less than the set pressure at a set cycle; reciprocating in a direction to expand the fluid space communicating with the fluid output port. During energization for driving the member, the signal level appearing in the signal line is checked at a predetermined cycle from the beginning of the member, and the number of times that it is a signal level indicating less than the set pressure is measured, A pressure signal abnormality detecting means for generating sensor abnormality information when the number of times is equal to or more than a set value; and the pressure detection in energization for driving the reciprocating member in a direction of expanding a fluid space communicating with the fluid output port. When the pressure detected by the means is equal to or higher than the first set pressure a, the energizing current value of the electric coil is sequentially changed at a predetermined rate of change through the energizing means in the direction of increasing the expansion. When the pressure detected by the force detection means is less than the first set pressure a and is greater than or equal to the second set pressure b, the rate of change is reduced to a low value, and when the pressure detected by the pressure detection means is less than the second set pressure b. When the sequential change of the energization current value is stopped and the pressure signal abnormality detection means generates sensor abnormality information, the energization current value is changed at a rate higher than the rate of change when the pressure is less than the first set pressure a and not less than the second set pressure b. A pumping device comprising a current value control means, which is sequentially changed. 4. A reciprocating member that communicates with a fluid output port and reduces / enlarges a fluid space containing an incompressible liquid, an electric coil for reciprocating the reciprocating member, and an electric coil of the electric coil. A liquid pump driven by a linear motor, comprising magnetic field generating means for applying a magnetic field in a direction orthogonal to the extending direction to the electric coil and generating a moving force in the forward / backward direction corresponding to the forward / reverse energization direction in the electric coil; Pressure detecting means for detecting the pressure of the fluid output port or the flow path communicating therewith; energizing means for applying forward / reverse current to the electric coil; this is shown when the pressure detected by the pressure detecting means is less than the first set pressure a. First comparing means for generating a first signal; second comparing means for generating a second signal indicating that the pressure detected by the pressure detecting means is less than a second set pressure b;
Monitor signal generating means for generating a monitor signal exhibiting a level change similar to that of the second signal; monitor signal transmitting means for transmitting the monitor signal to a signal line while the first signal is generated; Second to send to the signal line
Signal transmitting means; in energization for driving the reciprocating member in a direction of expanding a fluid space communicating with the fluid output port,
From the beginning to the set time, the signal level appearing on the signal line is checked in a predetermined cycle, and the number of times that it is the signal level corresponding to the second signal is measured, and the number of times during the set time is equal to or greater than the set value. A pressure signal abnormality detecting means for generating sensor abnormality information, and a signal level appearing on the signal line at a predetermined cycle in energization for driving the reciprocating member in a direction of expanding a fluid space communicating with the fluid output port. If it is not a signal level equivalent to the second signal, the energizing current value of the electric coil is changed by a predetermined step through the energizing means in the direction of increasing the expansion, and the signal level equivalent to the second signal is checked. A current value control means for holding this change at times, but changing it by a predetermined step when the pressure signal abnormality detection means is generating sensor abnormality information is provided. Pumping device.