Patent ID: 8282359

Claim:
An estimation and control system and rotary blood pump, comprising: a shaftless impeller located within a pump cavity in a pump housing, the housing having a fluid inlet and fluid outlet in fluid communication with the pump cavity; an impeller drive to rotate the impeller about an impeller axis so as to urge fluid from the inlet through the pump cavity to the outlet, wherein the impeller drive generates a drive torque on the impeller derived from a magnetic interaction between permanent magnets within the impeller and oscillating currents in windings encapsulated within the pump housing; and a controller configured to receive at least first and second input variables derived from the impeller drive and to calculate an operating point using the at least first and second input variables, and the controller configured to control the pump by comparing a predetermined operating point with the calculated operating point and by acting on the impeller drive so that the pump is maintainable at or near the predetermined operating point.