A method for physiological control of a cardiac assist device

This paper proposes a novel sliding-mode controller (SMC) to modulate the width of the voltage pulses driving the rotary blood pump, which is the actual control input in clinical settings. This controller is fed by the estimates of the input variables that are generated by the estimator. A lumped parameter model of the cardiovascular system, in conjunction with a proper dynamical model of the pump is used to carefully evaluate the performance of the controller via computer simulation tests. The tests dealt with various physiological conditions of the patient (transitions between normal and exercise). The results showed that the proposed controller is capable of tracking the required reference signal with a small error, is robust against the model uncertainties, and is featured by a quick and adequate response to changes in the cardiovascular conditions.