Method and apparatus for demodulating signals in a pulse oximetry system
US6229856A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 1998 |
| Grant date | May 8, 2001 |
| Priority date | — |
| Expiry date | Apr 10, 2018 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2562/0238
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A method and an apparatus measure blood oxygenation in a subject. A first signal source applies a first input signal during a first time interval. A second signal source applies a second input signal during a second time interval. A detector detects a first parametric signal responsive to the first input signal passing through a portion of the subject having blood therein. The detector also detects a second parametric signal responsive to the second input signal passing through the portion of the subject. The detector generates a detector output signal responsive to the first and second parametric signals. A signal processor receives the detector output signal and demodulates the detector output signal by applying a first demodulation signal to a signal responsive to the detector output signal to generate a first output signal responsive to the first parametric signal. The signal processor applies a second demodulation signal to the signal responsive to the detector output signal to generate a second output signal responsive to the second parametric signal. The first demodulation signal and the second demodulation signal both include at least a first component having a first freque…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.