Modifications of the Ventricular Assist Device

A report discusses some modifications of the ventricular assist device (VAD), which was described in "Small Implantable Pump Would Assist Circulation of Blood" (MSC-22424), NASA Tech Briefs, Vol. 20, No. 7 (July 1996), page 86. The VAD is a surgically implantable, miniature rotary pump designed to assist in pulmonary or systemic circulation of blood. The modifications, guided by computational simulations of blood flow in the pump, were directed partly toward reducing stagnant flow, backflow, and unsteady flow in order to reduce shear stresses and thereby reduce damage to blood cells and thereby, further, reduce clotting.