Overview of the extraction algorithm. The contaminated ECG is decomposed into 8 scales; the reference signal is then constructed by adding together the 6th and 7th sub-bands signals. A simple trigger generates the cardiac rhythm as well as the synchronization signal. Hi-D and Hi-R are respectively the high pass decomposition filter and its associated reconstruction filter. Lo-D and Lo-R represent the low pass decomposition and reconstruction filters. cDj denotes the detail coefficients, and dj are the reconstructed detail signals.