Design of a New Pulse Duplicator System for Prosthetic Heart Valves

This paper discusses results of a computer simulation for designing a new Introduction It is desirable that a pulse duplicator system for quantitative evaluation of mechanical heart valves is efficient for measurements, compact, and convenient to produce desired driving conditions of a valve to be tested. A major problem in pulse duplicator systems is a difficulty in accurate measurements of volume flow rate across the valve. To measure the small volume flow rate, for example, backflow volume rate during diastole with an electromagnetic flowmeter, zero flow has to be established after each individual test to recalibrate the flowmeter A new computer-controlled pulse duplicator system has been developed at the Freie Universitat Berlin. The developed pulse duplicator system is designed to be able to determine the accurate volume flow rate across a valve from the volume displacement of the actuator piston which directly drives the fluid. A further advantage is that this system is compact, since it does not need a circulatory loop. A simulated arterial hydraulic impedance is imposed on the actuator-valve system by use of a microprocessor. It is also an efficient system to make desired pressure-volume flow relationships across the valve, since they can be produced by simply changing the software on the microcomputer. A major purpose of the pulse duplicator system is to obtain the overall pressure-flow relation across a given valve. Obtained data will be used to make a mathematical model of the valve for control and estimation in artifical heart and human cardiovascular systems with mechanical heart valves