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:
Oct. 18, 1988
Filed:
Nov. 28, 1986
Lloyd C Hubbard, Minnetonka, MN (US);
Earl W Clausen, Wayzata, MN (US);
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Abstract
A heart/lung bypass system having a centrifugal blood pump driven by a motor detects reverse flow conditions in which blood is flowing from the load to the pump outlet. An alarm control provides an alarm signal based upon a flow magnitude signal, a pump speed (rpm) signal, and a torque signal. When the pump is at a desired initial speed and an arterial flow line from the pump is unclamped, a decrease in torque requirements indicates a reverse flow condition, and an alarm is initiated. Reverse flow conditions are also indicated by an increase in rpm followed by a decrease in flow magnitude, and by a decrease in rpm coupled with an increase in flow magnitude. In addition, when the pump is running at a constant rpm, an increase in flow magnitude followed by a decrease in torque indicates a reverse flow condition, and an alarm is sounded.