Cepstral transformation technique for dissociation of wide QRS-type ECG signals using DCT

Given a composite signal obtained by the addition of two periodic sequences with unequal period lengths, we address the problem of detecting the periodicity of one of the constituent rhythms with a relatively low signal power as compared to the dominant periodic component which exhibits wide deflections and large excursions. The cepstrally transformed discrete cosine transform (CTDCT) of the composite sequence is used for the reliable detection of the pulse locations in the low amplitude periodic component even for the case where the signal strengths of the two component rhythms differ by about 60 dB. A typical application of the proposed method for the analysis of electrocardiographic signals with wide QRS deflections is discussed.