Patent ID: 7809433
Filing Date: 2010-10-05
Classification: A61B,G06K

Abstract:
1. A method for processing a composite physiological signal having at least one physiological signal of interest and at least one unwanted spurious signal, the composite physiological signal having a first duration, the method comprising: determining a variable spurious signal threshold, said spurious signal threshold being determined as a function of signal spectral energy; or eliminating at least one narrow-band spurious signal in said physiological signal throughout said signal first duration that meets or exceeds said spurious signal threshold by performing a plurality of Fourier transforms, each of said Fourier transforms being performed on at least one of a plurality of overlapping temporal windows of said physiological signal, and filtering Fourier coefficients by reducing said Fourier coefficients in narrow bands of frequencies, whereby a window-to-window temporal variation of said Fourier coefficients to be filtered is distinguishably less than a window-to-window temporal variation of non-filtered Fourier coefficients; recreating an intermediate signal throughout substantially all of said physiological signal first duration by inverse Fourier transforming said filtered Fourier coefficients; eliminating at least one intermittently-occurring spurious signal in said intermediate signal by performing at least one wavelet analysis on said intermediate signal, said intermittently-occurring spurious signal including a plurality of intermittently-occurring wavelet coefficients, and filtering said intermittently-occurring wavelet coefficients by reducing or zeroing intermittently-occurring wavelet coefficients that are distinguishably greater than the remaining intermittently-occurring wavelet coefficients in said intermittently-occurring spurious signal; and recreating a second physiological signal in filtered form by performing a plurality or inverse wavelet analyses on said filtered intermittently-occurring wavelet coefficients.