An initial investigation of insulation fault effects on LVAD motor performance

Thousands of patients suffering from congestive heart failure (CHF) benefit from safe and reliable, temporary left ventricular assist devices (LVAD). Designed to perform in parallel with the left ventricle of the native heart, there are only five devices in the United States approved for use of up to 2 years to support CHF patients until a donor heart becomes available, or the heart recovers some function. With limited donor hearts (~3000), fully implantable LVADs are currently being designed for up to 10 years and are a complex medical device with multiple subsystems. The permanent magnet, brushless DC (BLDC) motor subsystem is evaluated for insulation failures using simulations of the electrical circuit model in MatLab (Mathworks). Variations in the number of turns lost and groundwall insulation have a direct effect on the current available to drive the motor. This preliminary model provides results that support the hypothesis that LVAD insulation failures lead to poor pump performance, and potentially, pump failure