The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 16, 2014
Filed:
Jan. 16, 2013
Thoratec Corporation, Pleasanton, CA (US);
Masamichi Yanai, Ann Arbor, MI (US);
Tao Zhang, Ann Arbor, MI (US);
Jeffrey G. Houdek, Canton, MI (US);
Thoratec Corporation, Pleasanton, CA (US);
Abstract
A centrifugal pump system for a cardiac assist device employs a disc-shaped impeller having an outer circumference adapted to be rotatably driven in a pumping direction. A pump housing has a pumping chamber receiving the impeller, wherein the pumping chamber defines 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 drives the impeller in response to a voltage provided to the motor. A current sensor measures current flow within the motor in response to the voltage. A controller estimates a pump flow rate in response to a predetermined relation between the measured current and the pump flow rate, wherein the predetermined relation includes a positive slope from a predetermined backflow rate to a zero pump flow rate.