SU328642A1 - DEVICE FOR AUTOMATIC CONTROL OF BLOOD EMISSION OF THE BLOOD PROTESIS OF THE VENTRICLE OF THE HEART - Google Patents

Description

The invention relates to medical technology.

Devices of a similar purpose are known, comprising electrocardiographic electrodes, a voltage amplifier, a cardiosynchronized pulse separation circuit, a waiting multivibrator, a power amplifier, and an electromagnetic valve. However, these devices do not adequately match the assisted perfusion with the needs of the patient. In addition, the design of the known devices is very complicated, since they contain pressure sensors installed in the bloodstream, which complicate the control system due to the need to use secondary amplifying devices, which makes the system unreliable.

The proposed device differs from the known ones in that it has a contact group located in the air chamber of the prosthesis pump, connected to the control pulse formation circuit. The output of this circuit is fed to one input of the inhibit trigger and to the first sawtooth generator, the output voltage of which is fed to the integrator. The latter is connected to one of the inputs of the comparison circuit, the second input of which is connected to the output of the second sawtooth generator

the voltage controlled by the output of the control trigger. One of the control trigger inputs receives a signal from the output of the comparison circuit, and the second from the output of the AND circuit, whose inputs are connected to the output of the waiting multivibrator and the output of the inhibit trigger. At the same time, the output of the control trigger in parallel is fed to the second input of the trigger trigger,

on the integrator and on the power amplifier.

Such an embodiment of the device according to the invention increases the compliance of the auxiliary perfusion with the needs of the patient and simplifies the device by eliminating pressure sensors.

The drawing shows a block diagram of the proposed device.

It contains heart-connected / electrocardiographic electrodes 2 connected to the input of the amplifier 3 electrocardiographic signals. The output of the amplifier 3 is connected to the input of the extractor-normalizer 4 of the R-wave of the electrocardiogram 1Y (ECG).

The normalized signal is sent to a continuous multivibrator 5, which forms the necessary delay of the control pulse relative to the R-tooth ECG. The output signal of the standby multivibrator 5 is connected to one of the inputs of the trigger trigger 7 of the controller. This trigger is part of the automatic control system of the control pulse duration, which also contains saw-tooth generators 8 and 9, the comparison circuit W, the integrator 11, the formation circuit 12 of control pulses fed to the contact group 13 mounted on the housing and working membrane 14 prosthesis 15 ventricle of the heart.

The prosthetic ventricle of the heart, which is a two-valve pump, is connected with the help of vascular prostheses to the atrium with one end and the output to the aorta (pulmonary artery). The onset of the pumping phase is synchronized with the ECG with the work of the heart in order to avoid a coincidence of the blood flow from the heart and the pump. Immediately after the end of the injection, the suction phase begins, during which the pump draws blood from the atria. The suction phase is continued until the pump is filled, as evidenced by the closure of the contact group 13. Then the zero speed period begins, i.e. the period when the working membrane 14 is stationary (between the end of the suction phase and the beginning of the next discharge phase). The zero speed period is determined by the time of the closed state of the contacts of group 13. The injection is not performed if the pump is not filled before the next clock pulse arrives.

This allows equality of impact surge and suction volume required for stable pump operation.

To automatically adjust the pump's shock output, the duration of the zero speed period is measured, and depending on this signal, the duration of the injection phase is adjusted so that, under these conditions, the zero speed period is reduced to a minimum. This period in the shock volume control system represents the signal error between the true duration of the suction phase and the maximum possible within a given cycle.

The system of automatic adjustment of the control pulse duration works as follows. The back front of the emulsion from the output of the waiting multivibrator 5 triggers control trigger 7. The trigger starts the generator 8 of the sawtooth wavelength, the output of which is connected to one of the inputs of the comparison circuit 10. An input proportional to the zero speed period is fed to the other input of this circuit. This voltage is generated as follows. After filling the pump, the contact group 13 closes, and a control pulse appears on the output of the formation circuit 12. This pulse triggers the second generator 9 of the sawtooth voltage. Amplitude of sawtooth pulses

at the output of this generator, proportional to the duration of the control pulses, is remembered at integrator 11, the output of which is connected to the second input of the comparison circuit 10. At the time of equality of the sawtooth voltage and voltage at the output of the integrator 11, the comparison circuit 10 generates a signal that triggers a trigger 7, at the output of which a control pulse is generated.

The pulse is amplified by a power amplifier 16 and fed to an electromagnetic distribution valve 17 connecting to an air chamber |: e prosthesis 15 of the ventricle of the heart or vacuum.

At the same time, the control pulse at the output of the trigger 7 discharges the capacitor of the sawtooth generator 8 and the integrator 11. The cycle is repeated. The prohibition scheme contains

the inhibit trigger 18 and the "H 6. Standby multivibrator 5 starts the control trigger 7 only if the AND circuit 6 is opened with the inhibitor trigger 18. which is triggered by the front of the control pulse from the circuit formed ;. 12. The trigger 18 is reset by the back pulse of the control pulse from the trigger 7 of the control.

Subject invention

A device for automatic control of a shock surge of blood from a prosthetic ventricle of the heart, comprising electrocardiographic electrodes, a voltage amplifier, a circuit for isolating cardio-synchronized pulses, a waiting multivibrator, an amplifier of power and an electromagnetic valve,

characterized in that, in order to increase the compliance of the auxiliary perfusion with the needs of the patient's body and the v-nponieiiiin device, it has 1 ontakgpa group located in the air chamber

prosthesis connected to the control pulse cxeMoii, the output of which goes to one of the inhibit trigger and the first Ienepiiiop of the sawtooth, the output of which goes to the integrator, the output of which is connected to one of the inputs of the comparison circuit, and the second input of the crawppei circuit is connected to the output of the second sawtooth generator, controlled by the control trigger output signal, one of the inputs of which receives a signal from the output of the reference circuit, and the second output of the circuit And, the inputs of which are connected with the output of the standby multivibrator and the output of the inhibit trigger, and the Wiravlepi Parallel trigger signal ;; and is available at the second trigger input 3anpciuc} ii i, at the integrator and at the power amplifier.

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