Physiological control of rotary left ventricular assist device

In rotary left ventricular assist device (LVAD), physiological control system is the element to automatically regulate the pump speed to ensure enough perfusion of patients. In this paper, the design of the physiological control system of rotary LVADs is reviewed first, such as criteria of physiological control system, sensors/signals, and control algorithms. Then the design of an adaptive optimal controller for permanent LVADs is discussed. A Matlab simulation program and an experimental mock circulatory loop are employed as test environments for the controller. Different physiological conditions, such as the variation of left ventricular failures and the variation of activities are simulated to study the performance of the designed physiological controller. Simulation and experimental results consistently show that the abnormal hemodynamic variables of a congestive heart failure patient are restored back to the normal physiological range by the designed controller.