A helical spring shape memory alloy actuator has been investigated to be used in a mechanical circulatory support system. The design procedure to determine shape memory alloy and passive bias spring specifications was established. A model device was designed to provide 2 cm stroke by a 100 cm2 pusher plate against a maximum 200 mm Hg pressure load. The prototype device was also developed to verify the feasibility of the shape memory alloy actuator and to confirm the design procedure. In vitro water bath test results verified the feasibility of the shape memory alloy actuator for use in a mechanical circulatory support system.