JPH0460670B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pump device for an artificial heart.

(Prior art) Two sac-type pulsating pumps are connected in parallel,
An artificial heart pump in which the drive cycle of each pulsating pump is controlled by a detector that detects the contraction and expansion of the sac portion of each pulsating pump was proposed by the present applicant, and was published in Japanese Patent Publication No. 33106/1983. It has been announced.

(Problem to be solved by the invention) However, as shown in the graph in Figure 6 (arterial pressure is maintained constant), the electromagnetic switching valve is activated by the contraction and expansion signals of the detector. When switching to regulate the stroke volume and automatically repeat pumping, the actual stroke volume changes depending on air pressure - arterial pressure = ejection force, and if the body's arterial pressure changes, it will change by 1. The ejection volume also changes. In other words, when fever and excitement occur in the body, arterial pressure increases, and venous return volume increases, the ejection force must be increased to increase the ejection volume, but if the air pressure remains constant, the ejection force is insufficient. Since the ejection volume of the pulsating pump decreases, blood accumulates in the veins and the venous pressure increases, and as shown in Figure 3, one of the sacs enters the systolic phase (detector 2 is L). t ₁ , t ₃ , t ₅ hours before the other sac part is in the expansion period (detector 1 is H), and the other sac part is in the expansion period (detector 1 is L) t ₂ , t ₄ , t ₆ hours ago, one of the sacs entered the expansion stage 4.
If detector 2 becomes H), or if the arterial pressure decreases during sleep or illness and the venous return volume decreases, the ejection force must be lowered to reduce the ejection volume, but the air pressure remains constant. Then, the blood according to the current ejection force is not returned to the pulsating pump on the expansion side,
As shown in Fig. 4, one sac part enters the systolic phase (detector 1 is L), and _one hour later, the other sac area enters the expansion phase (detector 2 is H); _Two hours before the expansion phase (detector 1 is H), the other sac part is in the systole phase (detector 2 is L). At this time, the restoring force of the pulsating pump applies negative pressure to the venous side, causing the venous pressure to become abnormally low.
There were problems such as the collapse of vein walls, which disrupted circulation and posed a danger to living organisms.

(Means for solving the problem) The present invention controls air pressure so that the amount of blood flowing in and the amount of blood being ejected are equal. In an artificial heart pump in which a pair of suction type pulsation type pumps are installed in parallel and are driven alternately with a pressurizing device in the middle of a branch pipe, the contraction and expansion of the suction part of the pulsation type pump is detected. A detector is provided, a pressure device is connected to compress the sac part, and a control device is used to calculate the time difference between contraction and expansion of the sac part based on the detection signal of the detector. A pressurizing force regulator is connected to the pressurizing device, and a pressurizing force regulator is connected to the pressurizing device, and the pressurizing force regulator is connected to the pressurizing device, and the pressurizing force regulator increases or decreases the pressurizing force to the suction portion based on the arithmetic processing result of the control device. The present invention is characterized in that the time difference between the contraction and expansion of both the sac portions is corrected by varying the extrusion time by increasing or decreasing the pressing force described above.

(Function) With this structure, when one of the sacs of a pair of pulsating pumps installed in parallel is compressed by a pressurizing device, the blood in the sac is ejected from the ejection-side conduit. Then, circulating blood flows into the other sac part of the pulsating pump, which is not pressurized by the pressurizing device and is under atmospheric pressure, from the inflow-side conduit, and this process is repeated alternately. Due to variations in the condition of the living body or the quality of the pulsating pump, the contraction and expansion timings of one sac part and the other sac part of the pulsating pump may not match, and one sac part is compressing (blood ejection). When the other sac is filled with blood at the same time as the other sac, the overlapping time of the swell periods H of both sacs is determined by the arithmetic processing of the control device based on the L (systole) and H (inflation) detection signals from the detector. It can be calculated accordingly. Then, the control device controls the pressurizing force regulator so as to increase the pressurizing force of the sac section to be pressurized next by the overlapping time of the expansion periods H based on the calculated value, and then the sac section is pressurized by the pressurizing device. Then, from the L-H detection signal detected by the detector, the expansion period H is again detected.
The control device calculates whether the expansion periods H overlap, and if the expansion periods H overlap, the pressurizing force regulator is controlled in the same way as above to increase the pressurizing force of the suction section to be pressurized next by the overlapping period. The ejection time of both pulsating pumps may be shortened alternately to reduce the time lag to zero. In addition, when one sac part finishes ejecting blood and the other sac part is not filled with blood, one sac part switches to the systolic phase L for a certain period of time based on the L-H detection signal of the detector. After the passage of time, the other sac part enters the expansion period H.
When the control device calculates that the pressure has been switched to , the pressure applied to the suction portion to be pressurized next is reduced by the time difference between the time when one suction portion contracts and the time when the other suction portion expands. The pressurizing force regulator is controlled by the control device, and the suction portion is pressurized by the pressurizing device. Next, the control device performs arithmetic processing to determine whether the L-H detection signal detected by the detector has a time lag, and if there is a time lag again, the sac section to be pressurized next by the lag time is The pressurizing force regulator can be controlled in the same manner as described above to lower the pressurizing force, and the ejection time of both pulsating pumps can be lengthened alternately to reduce the time lag to zero, which will not seriously affect the flow of blood. It is possible to equalize the amount of inflowing blood and the amount of ejected blood without any problem, and it is possible to correct the timing difference between contraction and expansion.

(Example) The present invention will be described in detail with reference to the illustrated example.

Reference numeral 1 denotes an inlet conduit made of a material that does not easily cause a coagulation reaction in blood, such as silicone rubber, and the forward part of the conduit 1 is branched into branch pipes 2, 2 made of the same material, and an ejection tube made of the same material. Connected and focused to the side conduit 3,
In addition, inlet valves 4 are provided at the intermediate portions of the branch pipes 2, 2 on the inlet and outlet sides of each branch pipe 2, respectively.
4, a pair of pulsating type valves 5, 5 on the ejection side, a sac part 6, 7 enlarged between the two valves 4, 5, and a shell body 8, 9 surrounding the sac part 6. Pumps 10 and 11 are provided in parallel. 12 is a pressurizing device for supplying compressed air that is connected to the shells 8 and 9 via a pipe 13, and the pipe 13 connected to the pressurizing device 12 is electrically connected to a control device 21 to be described later. Electromagnetic three-way switching valves 14 and 15 are provided, and the three-way switching valves 14 and 15 are switched to alternately compress the suction parts 6 and 7 of the pulsating pumps 10 and 11, and also to compress the suction parts 6 and 7 of the pulsating pumps 10 and 11. When the air is not compressed, the compressed air in the shells 8 and 9 is switched to exhaust, and the pressure inside the shells 8 and 9 is brought to atmospheric pressure. 16
is a pressure regulator connected to the pressure device 12 via a pipe 13, and the pressure regulator 16 is connected to the control device 21.
The pressure regulating valve 18 is regulated by the step motor 17 which is electrically connected to the pulsating pump 1, and the pressure regulating valve 18 is regulated by the step motor 17 which is driven by a signal from the control device 21.
Pressurizing device 12 supplied to shells 8 and 9 of 0 and 11
By increasing the air pressure, the amount of blood ejected is increased, and by lowering the air pressure, the amount of blood ejected is reduced, thereby increasing the blood ejection amount of the pulsating pumps 10 and 11. It works by shortening or lengthening the ejection time. 19,
20 is a detector attached to the pulsating pumps 10, 11 and electrically connected to the control device 21; It is detected from the distance between the shell bodies 8, 9 and the sac parts 6, 7, and is digitalized by shaping the waveform so that the systolic period is L and the expansion period is H using a preset voltage level. It consists of Hall elements 19a, 20a attached to the shells 8, 9 of the pulsating pumps 10, 11, and magnets 19b, 20b attached to the sockets 6, 7 of the pulsating pumps 10, 11. 21 is a control device electrically connected to the electromagnetic three-way switching valves 14 and 15 of the pressurizing device 12, the step motor 17 of the pressurizing force regulator 16, and the detectors 19 and 20;
The control device 21 computes and calculates at what timing the sac portions 6 and 7 contract and expand based on the detection signals of the systole L and expansion period H from the detectors 19 and 20. The pulsating pump is then alternately controlled by adjusting the pressurizing timing and pressurizing force for the suction parts 6 and 7 based on the calculated values. Then, due to variations in the living body, characteristics of the pulsating pump, etc., the ejection amount and inflow amount of blood do not match, and as shown in FIG. The state in which the sac 7 is filled with blood, that is, the detector 1
Before the detection signal of 9 switches to L (systolic phase), the detection signal of detector 20 changes to H (expansion phase) earlier by ut ₁ AA.
When it is calculated by the arithmetic processing of the control device 21 that the pressure has been switched to The pulsating pump 11 is controlled to increase the pressurizing force on the sac 7 by a time corresponding to the advanced time ut ₁ to shorten the ejection time of blood from the sac 7. If it is calculated from the next detection signal that the timing of expansion is earlier than that of contraction, then the pulsating pump 10 that performs pressurization is operated in the same manner as described above to shorten the ejection time, and the inflow The time difference is corrected by equalizing the blood volume and the ejected blood volume. Conversely, even when the suction portion 6 of the pulsating pump 10 has finished being compressed, the suction portion 7 of the pulsating pump 11 is not filled with blood, that is, even when the detection signal of the detector 19 switches to L. If the control device 21 calculates that the detection signal of the detector 20 will switch to H after dt ₁ when the detection signal is in the L state, the control device 21 adjusts the pressurizing force regulator 16 according to the calculated value. The step motor 17 is driven to adjust the pressurizing force regulator 16, and the pressurizing force on the sac part 7 is reduced by a time corresponding to the delay time _dt1 , thereby prolonging the ejection time of the blood in the sac part 7. Controls the pump 11. If it is calculated from the next detection signal that the timing of expansion is later than that of contraction, then the pulsating pump 10 that performs pressurization is operated in the same manner as described above to lengthen the ejection time. The time difference is corrected by making the inflow blood volume and the ejection blood volume the same. Also, three-way switching valve 1
Switching between 4 and 15 gives priority to the pulsating pump that is ejecting, and if one pulsating pump does not finish ejecting, it will not operate even if the other pulsating pump is already filled with blood. pumping is done alternately. Furthermore, as shown in Fig. 5, during one pumping cycle, the contraction period and the expansion period advance ut ₁ in time.
If there is a mixture of dt and dt ₁ , ignore the time advance ut ₂ that occurs in the next cycle. Also,
If a time delay dt occurs even if the time advance ut is ignored, the delay dt ₁ in n is calculated based on the time delay dt.
A non-response period is provided for 10 msec to 30 msec, and only when a delay of n or more occurs, the step motor 17 of the pressurizing force regulator 16 is operated in reverse by dt ₁ - n to lower the pressurizing force. If this happens, the entire system will become more stable. In addition to the detector using a combination of a Hall element and a magnet as in the example,
A light transmission type using infrared rays or a light reflection type may be used.In short, any type may be used as long as the contraction and expansion of the sac can be detected outside the sac. In addition to compressing the sac part and adjusting the pressure regulating valve with a step motor to change the pressing force, there is also a method of compressing the sac part using a motor and cam and changing the pressing force by changing the rotation speed of the motor. Of course, this is a good thing.

(Effects of the Invention) As is clear from the above description, the present invention uses a control device to perform arithmetic processing on detection signals from a detector that detects the timing of contraction and expansion of a pair of pulsating pumps installed in parallel. Based on the calculated time lag, the controller adjusts the pressure regulator to increase or decrease the pressure on the sac to shorten or lengthen the ejection time of the pulsating pump, thereby adjusting the inflow blood volume. By equalizing the ejected blood volume and correcting the time lag between contraction and expansion, there is no possibility that blood will accumulate in the veins, resulting in an abnormal rise in venous pressure or negative pressure in the veins. venous pressure drops abnormally,
It has the advantage that the venous walls do not collapse, disrupting circulation dynamics and posing a danger to the living body, and is of great benefit to medicine as it solves the problems of conventional artificial heart pump devices.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing an embodiment of the present invention, Fig. 2 is a time chart of the present invention, and Fig. 3 is a time chart when the inflow of blood becomes larger than the ejection capacity of the pump. Figure 4 is a time chart when the pump's ejection capacity exceeds the blood inflow. Figure 5 is a time chart when the blood inflow exceeds the pump's ejection capacity. A time chart when the ejection capacity exceeds the inflow of blood during one cycle. Figure 6 shows the switching of one air-driven pump using a solenoid valve based on the signal from the detector. It is a graph showing changes in each parameter of the pump caused by changes in air pressure when the pump is operated by switching the valves. 1: Inflow side conduit, 2: Branch pipe, 3: Ejection side conduit, 6, 7: Suck section, 10, 11: Pulsating pump, 12: Pressurizing device, 16: Pressurizing force regulator, 1
9, 20: Detector, 21: Control device.

Claims (1)

[Claims] 1 A pair of pump-type pulsating pumps 10 and 11 are provided with a pressurizing device 12 in the middle of a branch pipe 2 that is branched from a conduit 1 on the inflow side and connected to a conduit 3 on the ejection side and are driven alternately. In an artificial heart pump provided in parallel, a detector 1 for detecting contraction and expansion of the sac portions 6 and 7 of the pulsating pumps 10 and 11 is provided.
9 and 20 are provided, and a pressurizing device 12 for compressing the sac parts 6 and 7 is connected, and the time difference between contraction and expansion of the sac parts 6 and 7 is determined based on the detection signals of the detectors 19 and 20. A control device 21 that calculates by arithmetic processing is connected to the detectors 19, 20 and the pressurizing force regulator 16, and increases/decreases the pressurizing force for the above-mentioned SACK equations 6, 7 based on the arithmetic processing results of the control device 21. A pressurizing force regulator 16 is connected to the pressurizing device 12, and both the pulsating pumps 10, 1
1. A pump device for an artificial heart, characterized in that the time difference between the contraction and expansion of both the sac portions 6, 7 is corrected by varying the ejection time of 1 by increasing/decreasing the pressurizing force.