Method and apparatus for reducing ambient noise effects in electronic monitoring instruments
US5885213A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1997 |
| Grant date | Mar 23, 1999 |
| Priority date | — |
| Expiry date | Sep 17, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/02416
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The present invention provides a method and apparatus for adapting to noise sources affecting a pulse oximeter. Various available frequencies are evaluated to determine their respective noise levels and one is selected to act as the operating demultiplexer frequency. During normal operation of the pulse oximeter, the various available demultiplexer frequencies are periodically scanned to determine which has the lowest associated noise. The noise level associated with the operating frequency is used to determine the signal-to-noise ratio of the pulse oximeter signals and thereby qualify certain signals from the pulse oximeter. Those pulses associated with a signal-to-noise ratio below a predetermined threshold are rejected and excluded from use in calculating blood oxygen saturation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.