| 摘要 |
Acquisition and analysis of electrocardiogram signals, to non-invasively detect and quantify presence of abnormal cardiac conduction patterns in patients at risk of heart disease. Signals from the orthogonal (X, Y, and Z) surface leads are amplified (44, 36, 48), digitized (40) and either stored for later processing or processed immediately. The incoming beats can either be R wave triggered, aligned and ensemble averaged for patients at risk for ventricular pathologies, or P wave triggered, aligned and ensemble averaged for patients at risk for atrial pathologies. QRS onset and offset, and P wave onset and offset are calculated for ventricular and atrial post-analysis applications respectively. The windowed Fourier transform of the second derivative (acceleration) of the signal averaged ECG is calculated for regions of interest for each lead. A Spectral Change Index, calculated from the "acceleration spectrum" for each lead serves to quantify the degree of spectral fragmentation within a pre-specified bandwidth.
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