Hemodynamic aspects of the Berlin ventricle assist device

Abstract

A new ventricle assist device (VAD), with an improved energy converter unit, was investigated both numerically and experimentally. An experimental continuous digital particle imaging velocimetry (CDPIV) was combined with a computational fluid dynamics (CFD) analysis. These tools complement each other to result in a comprehensive description of the complex 3D, viscous and time-dependent flow field inside the artificial heart ventricle. A 3D numerical model was constructed to simulate the VAD pump and a time-dependent CFD analysis with moving walls was performed to predict the flow field inside the VAD during the cardiac cycle. A commercial finite element package (FIDAP, Fluent Inc., Evanston) was used to solve the Navier-Stokes equations. In the experimental analysis, an optically clear elastic model of the VAD was placed inside a 2D CDPIV system. Continuous flow visualization and CDPIV calculations of the flow were used for validating the CFD simulations. Once validated, the CFD results provide a detailed 3D and time dependent description of the flow field, allowing the identification of stagnation or high shear stress regions.