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Abstracts: ASAIO Cardiac Abstracts


Patel, Sonna M1; Allaire, Paul E2; Penrose, Howard W3; Untaroiu, Alexandrina2; Throckmorton, Amy L1; Wood, Houston G2; Olsen, Don B4

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Thousands of patients suffering from congestive heart failure benefit from safe and reliable ventricular assist devices (VADs). VADs, currently being designed for destination therapy are complicated medical devices that can potentially fail due to their complex configuration and individual component failures. The motor subsystem, as one of the only components in a rotary VAD that can be designed to be fault tolerant, is evaluated in order to increase pump performance and overall reliability.


Specific areas of the motor where faults can occur include the insulation system, which has been identified by multiple scientists as a primary cause of failure. This can occur as a result of a variety of failures including short and/or open circuits. To understand the effects of these failures, the three-phase brushless DC motor (BLDCM) with insulation is modeled as an electrical circuit utilizing MATLAB. Motor simulations are completed to evaluate the effects on the motor’s torque producing capabilities, speed, and efficiency.


Simulations of motor performance in MATLAB demonstrated the effects of insulation degradation on the BLDCM performance. Variations in the capacitance and resistance had a direct impact on the speed and torque of the motor as shown by the results. Overall motor efficiency clearly decreased due to insulation degradation, directly impacting patient health, safety, and well-being, thus proving that fault tolerance is a necessary addition to VAD motors.

Copyright © 2005 by the American Society for Artificial Internal Organs