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Abstracts: ASAIO Cardiac Abstracts


Patel, Sonna M1; Allaire, Paul E2; Lewis, Jeffrey P4; Untaroiu, Alexandrina2; Throckmorton, Amy L1; Wood, Houston G2; Olsen, Don B3

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Current medical devices must undergo significant failure and reliability testing prior to commercial approval by the FDA. Ventricular assist devices (VADs) have been developed for over 30 years and thousands of patients benefit from a safe and reliable mechanical circulatory support system (MCSS). Developing a reliability model for evaluation allows researchers to predict the overall performance of their device.


BlockSim (Reliasoft) is utilized to model the subsystems and components of the VAD. BlockSim has the capability to create complex systems and mathematically calculate system reliability, an essential assessment tool to prove safe and effective operation. The overall reliability is dependent on motor operation, the inlet and outlet cannulas, power supply, controller, human computer interface, the pump housing, Hall sensors, and magnetic (or mechanical) bearings. Appropriate reliability values are assigned to each block, which are obtained from blood pump and component manufacturers. The subsystems and components are arranged in series and parallel configurations, comparable to the actual functioning of the device.


The overall reliability of the VAD is clearly dependent on the functionality of the individual components that make up the system. With a few changes, this type of reliability model is readily applicable to other types of MCSS and medical devices.

Copyright © 2005 by the American Society for Artificial Internal Organs