AN INNOVATIVE METHOD FOR GENERATING PULSATILE BLOOD FLOW VIA AN AXIAL VENTRICULAR ASSIST DEVICE

Abstract

In recent years, ventricular assist devices (VAD) have received a worldwide admissibility and have become the unrivalled tools for replacing a failed heart. Most of the newer generations of these devices, including second and third generations, are designed to produce non-pulsatile flow at constant rotational speed. Here, we have proposed the design of a VAD, which although is an axial flow type, is able to produce pulsatile flow; and this has come through by changing the rotational speed of the impeller of the pump. This pump, which has an output analogous to cardiac output, is able to produce a flow rate of approximately 6 L per minute. Designing of this pump is based on turbomachinery theories and applying computational fluid dynamics (CFD) methods. The proposed pattern of the changes of rotational speed is trapezoidal and consists of four phases. Studies of the shear stresses imposed on the blood within the pump have shown that there has been an acceptable margin of safety for this pump in terms of blood injuries such as hemolysis and thrombosis.