Hydraulic force and impellor evaluation of a centrifugal heart pump

A rig was constructed to test the performance characteristics and compare the hydraulic forces exerted on a centrifugal type artificial heart impeller. A conventional shaft, seal and bearing system, while driven by a small electric motor, supported the impeller which was separated from the pump casing by a 6 axis force transducer (JR3 Inc). Radial (x,y) and axial (z) hydraulic forces were recorded and compared. At physiological operating conditions, the results indicate that the double entry/exit centrifugal pump encounters a smaller radial force and significantly reduced axial thrust. These experimental results are valuable in the design of a magnetic bearing system to suspend the impeller of a centrifugal artificial heart pump. This experimental technique may also be applied to evaluate the required capacity and predict the lifetime of contact bearings in marine pumps.