Problems arising in devising the assisted circulation apparatus and artificial heart can be solved only with investigations conducted on hydrodynamic models of the circulation system--the stands. An analysis of literature sources dealing with test stands justifies their classification according to the purpose, the types of tests, the specific structure and basic characteristics. It is necessary to proceed with further improvement of the stand equipment in the direction of creating a sufficiently accurate imitation of the anatomic structure and resilient properties of major arteries and veins, of constructing a geometrical and elastic model of the aorta, of pressure and flow control instruments at different points of the vessels, of the ones regulating the energy parameters, as well as of working out criteria for effectiveness of the devices to be used.
View Article and Find Full Text PDFIn 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).
View Article and Find Full Text PDFA systematization of methods for assisted circulation, based on the formulation of a concrete procedure, the nature of the deranged or lost function substitution and conditions for effective realization of such a substitution, is offered. This made it possible to classify the equipment for assisted circulation and to analyze the current trends of its further development. The most characteristic automation levels of the equipment under consideration and of generations of some apparatus, differing in the degree of automation, control and monitoring the process of assisted circulation, are presented in the form of tables and pictures.
View Article and Find Full Text PDF