Fig. 7From: Several insights into the preprocessing of electrograms in atrial fibrillation for dominant frequency analysisThe contrast of the DF results with and without 20 Hz low-pass filtering. a Original signal, fs = 2 kHz; b signal after 40–250 Hz band-pass filtering and rectification; c signal after 20 Hz low-pass filtering; d frequency spectrum and DF. DC component has been moved out in graph d Back to article page