Dynamic Model and Analysis of a Centrifugal Blood Pump and Induction Motor

A dynamic model of a centrifugal blood pump, induction motor, and channel is investigated through nonlinear analysis. A centrifugal blood pump with forward curved blades and an induction motor is subject to constant inlet and outlet mass flow conditions leading to a channel. The steady state pressure drop versus volumetric flow rate relation is described by a constitutive model containing a cubic nonlinearity obtained from centrifugal pump characteristic curves. Within certain operating regimes along the characteristic curve, the model exhibits self-excited pulsatile periodic morion and the qualitative features of the response can be understood in terms of the underlying model. Further, the mathematical model is a more general model and can be used by the designer of centrifugal blood pumps and other ventricular assist devices (VADs) to determine the instability mechanisms.