Design of a New Pulse Duplicator System for Prosthetic Heart Valves

This paper discusses results of a computer simulation for designing a new pulse duplicator system for mechanical heart valves. The design objective of the system is to obtain a compact, efficient pulse duplicator system capable of accurately measuring the volume flow rate across a valve. The volume flow rate is determined as the derivative of the volume displacement of an actuator piston which directly drives the fluid. The system does not need any circulatory loop, since the piston is controlled on-line to follow command signals representing an aortic impedance. The results of the computer simulation show: (1) the designed PI-controllers of the actuator can precisely control valve motion to follow given command signals, (2) the eigenvalues of the controllers have to be carefully chosen to prevent unstable behaviors of a valve in diastole, and (3) the dimensions of the actuator is optimized by minimizing a cost function of the total efficiency of the system.