Abstract
In this paper, linear oscillatory actuator (LOA) for the ventricular assist device (VAD) has been developed that provides reciprocating motion without using any converter mechanism. The LOA consists of a piece of stator with single-winding excitation coil and a piece of mover with two permanent magnets. The simple structure of LOA is based on fewer parts to bring about high reliability and smaller size. The principal feature of our LOA is the non-symmetry thrust characteristics that results from the unique structure of the stator-yoke. To drive VAD in a systole phase, a large force is necessary to the actuator. However, a small force is sufficient to drive VAD in a diastole phase. We developed the non-symmetry LOA which generates high thrust in a systole phase alone. A magnetic field analysis was applied to design our LOA. The dimension of the LOA to be developed is 60mm diameter and 24mm thickness with 68ml volumes and 465kg weights. In the systole phase at input power of 20 watts, the maximum static thrust was approximately 195N. In the diastole phase at same input 20 watts, the maximum static thrust was approximately 73N. The static thrust of systole phase was about 3 times larger than diastole with same input electric power.
