V.: Spatiotemporal blind source separation approach to atrial activity estimation in atrial tachyarrhythmias

Abstract—The analysis and characterization of atrial tach-yarrhythmias requires, in a previous step, the extraction of the atrial activity (AA) free from ventricular activity and other artefacts. This contribution adopts the blind source separation (BSS) approach to AA estimation from multilead electrocardio-grams (ECGs). Previously proposed BSS methods for AA extrac-tion—e.g., independent component analysis (ICA)—exploit only the spatial diversity introduced by the multiple spatially-sepa-rated electrodes. However, AA typically shows certain degree of temporal correlation, with a narrowband spectrum featuring a main frequency peak around 3.5–9 Hz. Taking advantage of this observation, we put forward a novel two-step BSS-based technique which exploits both spatial and temporal information contained in the recorded ECG signals. The spatiotemporal BSS algorithm is validated on simulated and real ECGs from a signif