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:
Nov. 03, 1987
Filed:
Sep. 28, 1983
John C Moise, Carmichael, CA (US);
Nimbus, Inc., Rancho Cordova, CA (US);
Abstract
Thrombus formation in an implantable blood pump is prevented by using a close-tolerance purge seal for the impeller shaft or rotor. A blood-compatible fluid is used for the purge fluid (which is preferably also the bearing fluid), and the purge flow into the blood stream presents to the blood stream a benign interface between the rotating and stationary parts of the pump. The rotating and stationary surfaces adjacent the interface are so configured as to present an essentially continuous smooth surface across the interface which can be swept by the blood stream and presents no cavities in which the blood can stagnate. The close clearances of the purge seal allow a sufficient purge flow rate to be maintained with only a minute amount of purge fluid; and in accordance with one aspect of the invention, the purge fluid can be derived from the blood stream by a protein-filtering membrane system so that no external replenishment of the purge fluid supply is necessary.