Patent ID: 8834345
Filing Date: 2014-09-16
Classification: A61M,F04D,F05D

Abstract:
1. A centrifugal pump system comprising: a disc-shaped impeller having an outer circumference and adapted to be rotatably driven in a pumping direction; a housing with a pumping chamber receiving the impeller, the pumping chamber defining an outlet volute having a separation edge spaced from the outer circumference to provide a limited backflow path coinciding with the pumping direction; a motor for receiving a voltage and for driving the impeller in response to the voltage provided to the motor; a current sensor for measuring a current flow within the motor in response to the voltage; and a controller having a predetermined relation between the measured current and the pump flow rate, wherein the controller estimates the pump flow rate in response to said predetermined relation wherein the predetermined relation includes a positive slope from a predetermined backflow rate to a zero pump flow rate.