System and method for the algebraic derivation of physiological signals
US5687722A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 1995 |
| Grant date | Nov 18, 1997 |
| Priority date | — |
| Expiry date | Jul 26, 2015 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/7239
- WIPO fieldMedical technology
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.