Preprocessing of the BSPM Signals with Untraditionally Strong Baseline Wandering

The BSPM is a special setup of the ECG measurement with many of electrodes (20–256) on the body surface. Results of the measurement are strongly dependent on many conditions like body shape, contact of electrodes and skin, patient position and movements. Of course, these conditions are crucial also for standard ECG measurement, but obviously, problems with the conditions are more probable during the BSPM signals acquisition. In this paper, we would like to present a problem with the Body Surface Potential Mapping (BSPM) ECG preprocessing caused by unexpected signal interruption due to the significant baseline wandering and derivate problems which are generated by solving of this baseline wandering filtration. This problem is major for next signal processing (mainly ECG delineation) because the baseline wandering problem is closely connected with the determination of ECG signals’ isoline. We use a system of 120 electrodes on body front and back. The experimental measurements are arranged in the clinical environment with maximal treatment to electrodes position and contact of electrodes and skin at the beginning of the measurement. Unfortunately, obtained signals contain often extreme baseline wandering bedsides of standard artefacts. This baseline wandering seems to be created most likely by patient movements and a change of the electrodes contact. Moreover, we have observed that the standard artefact filtration and the extreme baseline wandering filtration are against each other.