SU1600779A1 - Method of controlling apparatus of assisted blood circulation - Google Patents

Abstract

The invention relates to medical technology and can be used in an assisted circulatory apparatus. The aim of the invention is to accelerate the optimization of the timing of the discharge phase of the heart pump. This goal is achieved by measuring the duration of each cardiac cycle, then determining the current values of the beginning and end of the diastole of the heart. The value of the beginning of the pumping phase of the heart pump is determined taking into account the first additional time interval. The value of the end of the pumping phase of the heart pump - as the current value of the end of the diastole of the heart, taking into account the second additional time interval, the extreme adjustment of the values of the beginning and end of the pumping phase of the heart pump is carried out by correcting the values of the first and second additional time intervals.

Description

The invention relates to medical technology and can be used in assisted circulatory devices.

The aim of the invention is to accelerate the optimization of the timing of the discharge phase of the heart pump.

The method is implemented as follows.

The electrodes of the cardiosynchronizer and the pressure transducer of the electromanometric converter, which are part of the auxiliary blood circulation apparatus, as well as the cardiac pump, are connected to the patient and include the AVA. At the same time, the ECG and aortic pressure curve are displayed on an oscilloscope, and the aortic pressure curve is also fed to one of the inputs of the information processing device for calculating a generalized criterion of the cardiac output voltage in each heart cycle (for example, time to diastolic)

as well as some blood pressure parameters (for example, medium systolic, mid-diastolic, average per cycle, maximum systolic and minimum diastolic pressures). At the same time, the signal corresponding to the R-wave of the ECG from the cardiosynchronizer output goes to another input of the information processing device, which measures the duration of each cardiac cycle and, based on the duration of the previous R-R interval, determines the current values of the beginning and end of the diastole of the heart. The current end of the diastole of the heart (Ti5n) is defined as the end of the time interval equal to the duration of the previous R-R interval, and the current start of the diastole of the heart () is the end of the time interval defined by the formula

T "A 0.12Tu-f 0.235s, (1)

O5

WITH

where Ti is the duration of the previous cardiac cycle.

Information on the current start (Ted) and end (TCD) of the cardiac diastole thus determined from the outputs of the information processing device is fed to the first and second adjustable delay circuits, respectively, which determine the start (H) and end (K) values of the pumping phase of the heart pump. according to formulas

H ,, (2)

; To Tcl-12, (3)

ria, e ti and t2 are the first and second additional time intervals set by a: Automatically when AVK is turned on.

The ti and t2 values can be adjusted using separate controls and are based on the drive speed parameters given in the AVC technical documentation and the personal experience of the operator. The signals of the beginning (H) and end (K) of the discharge phase from the outputs of the adjustable delay circuits are fed to the corresponding inputs of the drive unit, which generates the pneumatic signals that control the operation of the heart pump. Thus, already in the second, after switching on the AVK cardiocycle, the temporal parameters of the heart pump operation are determined by the values of the beginning (H) and end (K) of the discharge phase, set in accordance with the formulas (2) and (3), which increases the efficiency of the initial stage of ancillary perfusion, as the pumping phase of the heart pump. Maximum occurs in diastole of the heart. Then from cycle to cycle with discreteness D, which can also be adjusted by the operator JJlpo, the correction of the values of the first and second additional time intervals ti and iz. At the same time, the shape of the pressure curve displayed on the oscilloscope is monitored, and the value of the generalized criterion of the working voltage of the heart, a decrease in which indicates an increase in the efficiency of auxiliary perfusion. When the generalized criterion of the working heart voltage reaches its minimum value, the correction ti and iz cease, and the mode of operation of the AVK is considered optimal. Moreover, such a solution to the problem of forming the values of the beginning and end of the pumping phase of the heart pump makes it possible to reduce the discrete resolution D of the ti values in comparison with the prototype

 2The benefits of the proposed method

This is an increase in the effectiveness of the initial stage of ancillary perfusion and patient safety due to an increase in the accuracy of the phase matching of the AVC's work with the patient's heart, as well as the possibility of uncomplicated instrumentation. In addition, the application of the invention speeds up the optimization process.

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Claims (1)

Invention Formula A method of controlling the secondary circulation apparatus by determining a generalized criterion of the working voltage of the heart and the extreme one. regulation 5 values of the beginning and end of the phase of injection of the cardiac pump, characterized in that, in order to accelerate the optimization of the timing parameters of the phase of injection of the cardiac pump, the duration of each cardio cycle is measured, then the current values of the beginning and end of the diastole of the heart are determined; cardiac pump is defined as the current value of the onset of the diastole of the heart, taking into account the first additional time interval, and the value of the end of the pumping phase of the cardiac 5 of the pump - as the current value of the end of the diastole of the heart, taking into account the second additional time interval, extreme regulation of the values of the beginning and end of the discharge phase of the heart pump is carried out by correcting the magnitude of the first and second additional time intervals. 0