Physiological control of implantable rotary blood pumps for heart failure patients.

In general, patient variability and diverse environmental operation makes physiological control of a left ventricular assist device (LVAD) a complex and complicated problem. In this work, we implement a Starling-like controller which adjusts mean pump flow using pump flow pulsatility as the feedback parameter. The linear relationship between mean pump flow and pump flow pulsatility forms the desired flow of the Starling-like controller. A tracking control algorithm based on sliding mode control (SMC) has been implemented. The controller regulates the estimated mean pulsatile flow (Qp) and flow pulsatility (PIQp) generated from a model of the assist device. A lumped parameter model of the cardiovascular system (CVS) was used to test the control strategy. The immediate response of the controller was evaluated by inducing a fall in left ventricle (LV) preload following a reduction in circulating blood volume. The simulation supports the speed and robustness of the proposed strategy.