Signal processing apparatus and method
US7499741B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 2004 |
| Grant date | Mar 3, 2009 |
| Priority date | — |
| Expiry date | Aug 6, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2218/04
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A method and an apparatus to analyze two measured signals that are modeled as containing desired and undesired portions such as noise, FM and AM modulation. Coefficients relate the two signals according to a model defined in accordance with the present invention. In one embodiment, a transformation is used to evaluate a ratio of the two measured signals in order to find appropriate coefficients. The measured signals are then fed into a signal scrubber which uses the coefficients to remove the unwanted portions. The signal scrubbing is performed in either the time domain or in the frequency domain. The method and apparatus are particularly advantageous to blood oximetry and pulserate measurements. In another embodiment, an estimate of the pulserate is obtained by applying a set of rules to a spectral transform of the scrubbed signal. In another embodiment, an estimate of the pulserate is obtained by transforming the scrubbed signal from a first spectral domain into a second spectral domain. The pulserate is found by identifying the largest spectral peak in the second spectral domain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.