Observer of autonomic cardiac outflow based on blind source separation of ECG parameters

We present a novel method which provides an observer of the autonomic cardi ac outflow using heartbeat intervals (RR) and QT intervals. The model of th e observer is inferred from qualitative physiological knowledge. It consist s in a problem of blind source separation of noisy mixtures which is resolv ed by a simple and robust algorithm. The robustness of the algorithm has be en assessed by numerical simulations in adverse noisy environments. In clin ical applications, we have validated the observer on subjects exposed to ex perimental conditions known to elicit sympathetic or parasympathetic respon se.