System and method for the extractment of physiological signals
US5662105A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 17, 1995 |
| Grant date | Sep 2, 1997 |
| Priority date | — |
| Expiry date | May 17, 2015 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/7239
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A technique for the accurate determination of artifact free pulse oximetry signals utilizes an adaptive signal processor and peak detector circuit. A reference signal for the adaptive signal processor is derived based on mathematical relations of the detected light signals and the true intensity of light signals. The derivation of the appropriate reference signal requires the determination of peak values for two ratio constants. The two ratio constants lie within a known physiological range of values. When the value of the ratio constants has been determined, the reference signal equals the true intensity. The output of the adaptive signal processor is provided to the peak detector. The peak detector subdivides the known physiological range into two intervals and determines in which interval a peak exists. The remaining interval is discarded, and the peak detector repeats the measurement on the remaining interval until a peak has been detected within the desired accuracy. The value corresponding to the detected peak is one of the ratio constants. In a second alternative embodiment, the output of the adaptive filter is fed directly to the peak detector to determine values for the tw…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.