Patent ID: 7286983

Claim:
A method of real-time signal processing, the method comprising: acquiring an analog signal, wherein said analog signal comprises a time-varying acoustic signal or a time-varying physiological signal; setting: an initial state of a digital model of an expected signal; and an initial error variance between said initial state of the digital model and a digital representation of the analog signal; calculating a plurality of estimates of the state of said digital model, each of said plurality of estimates corresponding to a point in time, as follows: for each point in time, calculating: a filter gain for the point in time, the filter gain comprising a function of: the initial error variance or prediction of the error variance; the relationship between the digital model and a measurement of an output signal; and a decay factor; an improved estimate of the state of said expected signal for the point in time based on said calculated filter gain, a prediction of the state of said expected signal for the point in time and on an observation of said analog signal; an update of the estimate of the error variance for the point in time based on said calculated filter gain; and a prediction of the state of said expected signal and a prediction of the error variance for the next point in time; processing said analog signal according to the digital model to generate the output signal, the output signal comprising a processed signal representing the time-varying acoustic signal or the time-varying physiological signal having an improved signal-to-noise ratio; and outputting the processed signal in order to analyze a physiological response.