The response of a continuous flow magnetic bearing supported ventricular as
sist device, the CFVAD3 (CF3) to human physiologic pressure and flow needs
is varied by adjustment of the motor speed. This paper discusses a model of
the automatic feedback controller designed to develop the required pump pe
rformance. The major human circulatory, mechanical, and electrical systems
were evaluated using experimental data from the CF3 and linearized models d
eveloped. An open-loop model of the human circulatory system was constructe
d with a human heart and a VAD included. A feedback loop was then closed to
maintain a desired reference differential pressure across the system. A pr
oportional-integral (PI) controller was developed to adjust the motor speed
and maintain the system reference differential pressure when changes occur
in the natural heart. The effects of natural heart pulsatility on the cont
rol system show that the reference blood differential pressure is maintaine
d without requiring CF3 motor pulsatility.