06067462 is referenced by 645 patents and cites 57 patents.

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.

Title
Signal processing apparatus and method
Application Number
834194
Publication Number
6067462
Application Date
May 19, 1998
Publication Date
May 23, 2000
Inventor
Rex McCarthy
Mission Viejo
CA, US
Mohamed K Diab
Mission Viejo
CA, US
Agent
Knobbe Martens Olson & Bear
Assignee
Masimo Corporation
CA, US
IPC
A61B 5/00
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