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. 18, 1997
Filed:
Jul. 26, 1995
Jonathan Tien, Redmond, WA (US);
David R Marble, Seattle, WA (US);
SpaceLabs Medical, Inc., Redmond, WA (US);
Abstract
A technique for the algebraic derivation of a pulse oximetry signal uses the mathematical relations of detected light signals. First and second light sources transmit light through the patient's finger or reflects light off the blood vessels in the patient's finger. A light detector detects light from each of the light sources and generates a measured intensity signal. The measured intensity signal includes the true intensity of light transmitted from each of the light sources as well as noise introduced during the measurement process. A data sample from each of the light sources is digitized and subdivided into a plurality of data windows. The mathematical relationship is applied to each of the data windows to determine a ratio value indicative of oxygen saturation in the patient. The ratio values are statistically analyzed to determine the best estimate for the correct ratio value. This ratio value is subsequently processed to determine the oxygen saturation within the patient.