Abstracts: ASAIO Cardiac Abstracts
LEV-VAD: COMPUTATIONAL DESIGN AND EXPERIMENTAL TESTING
Thousands of cardiac failure patients per year in the US could benefit from long-term mechanical circulatory support as destination therapy. To provide an improvement over currently available devices, we have designed a fully implantable axial flow ventricular assist device with a magnetically levitated impeller (LEV-VAD). In contrast to currently available devices, the LEV-VAD has an unobstructed blood flow path, generating substantially less retrograde and stagnant flow.
The pump design included the extensive use of conventional pump design equations and computational fluid dynamics (CFD) modeling for predicting pressure-flow curves, hydraulic efficiencies, scalar fluid stress levels, and exposure times. Flow performance testing was completed on a plastic prototype of the LEV-VAD for comparison to the CFD predictions. Animal fit trials were completed to determine optimum pump location and cannulae configuration for animal implantations.
Per the CFD results, the LEV-VAD produces 6 lpm and 100 mmHg at a rotational speed of 6,300 RPM. The pressure-flow performance predictions demonstrated the VAD’s ability to deliver adequate flow over physiologic pressures. The CFD numerical estimations generally agree within 10% of the experimental measurements over the entire range of rotational speeds tested. Animal fit trials revealed that the LEV-VAD’s size and configuration were adequate requiring no alterations to cannulae configurations for future animal testing.Copyright © 2005 by the American Society for Artificial Internal Organs