Patent ID: 7079880

Claim:
A method for measuring a physiological parameter, comprising: measuring a plurality of signals, wherein each of said signals comprises a source component corresponding to said physiological parameter and an interference component; processing said plurality of signals to obtain a plurality of principal components; processing said plurality of principal components to obtain a plurality of independent components, wherein a matrix of said plurality of signals corresponds to a matrix product of a matrix of said plurality of independent components and a matrix of mixing coefficients; and extracting a first measure of said physiological parameter corresponding to said source component from one of said plurality of independent components, wherein said plurality of signals corresponds to sensed optical energies from a plurality of wavelengths, and wherein said processing said plurality of principal components comprises maximizing a function of a third-order cumulant of said plurality of signals, thus separating said source component from said interference component, and obtaining a ratio of mixing coefficients from said matrix of mixing coefficients, wherein said ratio corresponds to a ratio of modulation ratios of red to infrared signals, wherein said plurality of signals comprise modulated optical signals in the red and infrared ranges.