Abstract
A new feedback control system for a currentbased model of the combined cardiovascular system and a rotary left ventricular assist device is presented. The system consists of a suction detection subsystem and a feedback controller subsystem. The suction detection subsystem is based recursive DFT algorithm developed by the author. A constant set point is used as part of the feedback controller to compare with the calculated pulsatility control index in order to continuously update the pump current. In the absence of suction in the left ventricle, as indicated by the suction detection subsystem, the proposed feedback controller automatically adjusts the pump motor current in order to meet the blood flow requirement of the patient's body at different physiological states. The performance of the control system was tested in simulations over a wide range of physiological conditions using a lumped parameter model of the circulatory system coupled with a left ventricular assist device. The controller was able to maintain cardiac output within acceptable physiologic ranges, while avoiding suction, demonstrating the feasibility of the proposed control system.