A magnetic bearing system for a continuous ventricular assist device

This article describes a prototype continuous flow ventricular assist devic e (CFVAD3) supported in magnetic bearings. The VAD is a small centrifugal F our bladed pump, The pump's geometry is explained. The CFVAD3 is the first compact VAD completely supported in magnetic bearings. The magnetic bearing s are composed of an inlet side actuator divided into eight pole sets, and an outlet side actuator, also divided into eight pole sets. The pump operat ing performance was tested and found to be within the design flow rate of u p to 9 L/min, and head up to 170 mm Hg for human circulatory support. Magne tic bearing operation out of center positions under various operating orien tations were measured and found to be <1/6 of the bearing clearance, well w ithin specifications, The expected magnetic bearing power loss has been cal culated at approximately 6.5 watts.