Calculation of input impedance to reproduce the aorta in a mechanical circulatory system

A mechanical circulatory system (MCS) has been developed in order to evaluate artificial organs, including circulatory assist devices and artificial prosthetic heart valves. An effective functioning MCS, which is similar to the natural system, would allow us to use it as a substitute for animal experimentation. The purpose of this study is to reproduce the aorta in the MCS. This simulator includes a fluid circuit, drive and measuring systems. The fluid circuit consists of an artificial atrium, ventricle and aorta which physically and functionally designed to be almost identical to those of natural organs with reference to an anatomical weight of 60 kg. Input impedance was calculated with a personal computer from pressure and flow rate measured at the aorta in the MCS. The impedance analysis data from the silicone aorta indicated that at a minimum modulus of impedance occurred at the 4th harmonics in phase. This input impedance pattern obtained was close to that of the natural aorta.