Patent ID: 7117029

Claim:
A computer-readable medium encoded with data and being loadable in a digital data processing system for deriving indices characterizing atrial arrhythmias, said data programming said digital signal processing system to: acquire a digital representation of a time-domain electrical signal originating from atria of a heart; temporally isolate a portion of the digital representation of the time-domain signal within a variable location time window; frequency analyze the temporally isolated portion to obtain a frequency spectrum having a fundamental frequency peak and at least one harmonic thereof; compare the obtained frequency spectrum with a template frequency spectrum having a template fundamental frequency peak and at least one template harmonic thereof to determine a frequency shift value and an amplitude value that optimize a correlation between the obtained frequency spectrum and the template frequency spectrum; and emit an output representing the frequency shift value and the amplitude value as respective indices characterizing atrial arrhythmias in said electrical signal.