Impact of the approximated on-line centering and whitening in OL-JADE on the quality of the estimated fetal ECG

OL-JADE is an on-line method for fetal ECG extraction from non-invasive potential recordings, able to work in real-time on a DSP. With respect to the original JADE algorithm, it exploits a recursive sample-by-sample approximated centering and whitening stage that partially violates the requirements of the subsequent JADE stage. In this paper this aspect is investigated showing a comparison with another similar algorithm, tracking BLISS, on artificial mixtures of real signals. OL-JADE presents a reduced complexity and, in case of time variances in the mixing process, permutations are confined to the involved sources. The imperfect centering and whitening have limited consequences in terms of signal distortions in presence of time variances, restricted to the time span of such variations.