[Methods of cardiac synchronization in assisted circulation].
In assisted circulation cardiosynchronization should be regarded as a process of monitoring the arterial blood pressure within the limits of the cardiac cycle and changes of its form with the aim of improving the energy balance of the heart. The coordination of the pumping function and that of the cardio-vascular system comes to a problem of shaping the monitoring action that depends upon three variables, viz. the time lag tepsilon, actuation of the unit relative to the base cardiosignal, duration of the pumping phase tpi and the signal level at the pump's inlet U(t). A number of researchers consider tepsilon and tpi to be a function of the cardiac contractions period and determine them in different ways, employing for this purpose extrapolation, stochastic characteristics, etc. Of late, in addition to the period of cardiac contractions extremal, mean integral values of the systolic and diastolic pressure, the level of pressure at the instant of the cardiac valves closure and others have also come in use. There are shortcomings in the proposed cardiosynchronization algorhythms: their empiric nature and also the fact that the monitoring action includes merely variables tepsilon and tpi and does not carry function U(t), which reflects the intensity of the pump's operation.