摘要 |
A temporally isolated portion of a digital representation of a time-domain electrical signal originating from the atria of a patient is frequency analysed by analyser (14) to provide a corresponding frequency spectrum. A comparator (16) is arranged to compare the obtained frequency spectrum with a template frequency spectrum, selectively adapted (18) dependent on previously obtained frequency spectra from different temporally isolated portions, to determine a frequency shift value and an amplitude value optimising a correlation between the two spectra. An output representing the two determined values is used by an event classification means (22,24), preferably together with parameters describing the template frequency spectrum, to classify an atrial arrhythmia manifest in the digital representation. <IMAGE> |