PULSATILE OPERATION OF A CENTRIFUGAL VENTRICULAR ASSIST DEVICE WITH MAGNETIC BEARINGS

A prototype bench top model of a continuous flow ventricular assist de vice using an impeller suspended by magnetic bearings has been develop ed. Generation of a pulsatile pressure was studied using both a comput er model and in vitro loop tests of the prototype. The motivation for developing a computer model for a blood pump in the natural circulatio n is two-fold. First, it allows simulation of the pump under a large v ariety of operating conditions. Second, it provides insight into what parameters of the system design are important for achieving a specific result. For example, in one case, an aortic pressure of 118/87 mmHg w as generated by varying the speed from 2,000 to 2,600 rpm. The compute r model was verified by coupling the centrifugal pump prototype to a m ock circulatory system. The results of the model were verified by gene rating an aortic pressure of 113/78 mmHg while varying the speed from 2,000 to 2,600 rpm. These experiments have shown that it is possible t o generate pulsatile pressure similar to that of native physiology usi ng a centrifugal left ventricular assist device. further tests will be required to quantify the effects on hemolysis.