Computational analysis of the three-dimensional hemodynamics of the blood sac in the twin-pulse life-support system

Abstract

Blood flow in the twin-pulse life-support system (T-PLS) pulsatile blood pump was simulated using a three-dimensional rigid body-fluid-solid interaction model. This model can delineate the blood flow in the T-PLS resulting from operation of a moving actuator. The numerical method used in this study was a commercial finite element package called ADINA. We used a contact and fluid-solid interaction model to compute the blood hemodynamics in the sac. Blood flow is generated by the motion of the actuator, which strongly interacts with the solid material surrounding the blood. To obtain basic bioengineering data on the optimum operation of the T-PLS, we simulated four models in which the actuator moved at different speeds and investigated both the flow pattern and the distribution of shear stress. During the contraction phase, a strong axial flow is observed around the outlet, whereas there is stagnant flow around the inlet. The maximum shear stress in each model depends on the operation mode; however, all four models have similar flow rates. The sinusoidal mode exhibited the lowest maximum shear stress and is thus considered the most efficient of the four operating modes.