PHASE-SPACE EMBEDDING OF ELECTROCARDIOGRAMS

We study properties of the human electrocardiogram under the working h ypothesis that fluctuations beyond the regular structure of single car diac cycles an unpredictable. Against this background we discuss the p ossibility of using the phase space embedding method for this kind of signal. In particular, the specific nature of the stochastic or high-d imensional component allows us to use phase space embeddings for certa in signal processing tasks. As practical applications, we discuss nois e filtering, fetal ECG extraction, and the automatic detection of clin ically relevant features. The main purpose of the paper is to connect results of embedding theory that have not been previously applied in p ractice, and practical applications that have not yet been justified t heoretically. [S1063-651X(98)10911-X].