Patent ID: 8478538

Claim:
A method of extracting a signal parameter from a generally repetitive signal, comprising: obtaining, using a specifically programmed processor, an original photoplethysmograph (PPG) signal from a sensor; applying, using the specifically programmed processor, a filter transformation to the original PPG signal to substantially remove a pulse component from the original PPG signal and produce a baseline PPG signal; determining, using the specifically programmed processor, one or more regions of the baseline PPG signal by applying a threshold to the baseline PPG signal, wherein the values of the threshold depend, at least in part, on a set of signal amplitude values of the baseline PPG signal; selecting, using the specifically programmed processor, a region from the one or more regions, and processing a portion of the original PPG signal corresponding to the selected region; and extracting, using the specifically programmed processor, the signal parameter from the processed portion of the original PPG signal.