3D Flow Characteristics in Ventricular Assist Devices: Impact of Valve Geometry and Operating Conditions

Fig. 3: 3D flow characteristics inside the VAD during the peak outflow phase (systole). The gray shaded area represents an iso-surface rendering of the magnitude data and shows the VAD geometry including pump chamber and valve systems at inand outlet. A: A novel valve design using a differently shaped valve support region resulted in improved VAD performance. In addition to improved filling of the out-flow cannula (red arrows compared to solid yellow arrow), vortex formation proximal to the in-flow valve was virtually eliminated. B: The effect of different operating conditions in the same VAD clearly resulted in considerable differences in VAD function. Compared to normal operating conditions, insufficient VAD filling resulted in reduced filling and velocities during out-flow. Insufficient emptying lead to impaired clearing of the pump chamber (small white arrows) while marinating high out-flow velocities (open yellow arrow). Vortex formation proximal to the inlet valve was clearly visible for all operating conditions (open white arrows)