| Compression cardiac assist device aims to help patients with end-stage dilated heart failures. Currently the compression cardiac assist devices under development are driven by air or liquids, in which tubes are needed for connecting devices with outside pumps through the skin. These flexible tubes may cause infections and inconvenience of mobility for patients. Therefore, it is necessary to exploit new actuators for compression cardiac assist devices. Ultrasonic motors are potentially attractive actuators for compression cardiac assist due to their fast response, large force density, easy miniaturization, and silent motion. In this paper, the assistance pressure of compression cardiac assist devices is obtained directly from the ratio of contracting force to the area with a thin, homogeneous, truncated sphere left ventricle model; the characteristics of ultrasonic motors are taken from smallest commercial available linear ultrasonic motors without consideration of motor structure influences for simplification, and then the simulations are completed based on physiological simulation benchmark experiment (PHYSBE). Simulation results indicate that a 10ml reduction of dilated left ventricle volume has achieved. |