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:
Feb. 24, 2004
Filed:
Oct. 10, 2001
D. Alan Hanna, Boulder, CO (US);
Datex-Ohmeda, Inc., Madison, WI (US);
Abstract
The present invention provides a reduced wire count voltage-drop sense system and method wherein the voltage drop across a load device is determinable using only one sense lead regardless of the number of load devices. In one embodiment, the voltage drop across any one of four LEDs ( A-D) in a photoplethysmographic probe when a drive current is applied therethrough via one of four input drive leads ( A-D) connected to separate LED terminals ( A-D) is determinable from a first voltage drop and a second voltage drop, for example, by subtracting the second voltage drop, or a portion thereof, from the first voltage drop. The first voltage drop is measurable across a terminal ( A-D) of the input drive lead ( A-D) connected to the LED ( A-D) across which the voltage drop is to be determined and a terminal ( ) of a sense lead ( ) connected to a common LED terminal ( ). The second voltage drop is measurable across the sense lead terminal ( ) and a terminal ( ) of a common drive lead ( ) connected to the common LED terminal ( ).