Extended triangle phase space mapping: Novel method for representation of heart rate variability signals

In this paper, we have introduce new features in the Extended Triangle Phase space mapping (ETPSM), a novel method for representation of heart rate which is obtaining by using RR interval time series signal to plot the Triangle mapping consist of all the ordered pairs: (RRi, abs (RR-RR_i+1)), i = 1, ..., N where RR is the mean of RR intervals. We obtained a triangle from the distribution of these points and introduced three new features in this mapping by counting the points in, on and out of the triangle. These features were evaluated in distinguishing four groups of subjects (Arrhythmia, Congestive Heart Failure (CHF), Atrial Fibrillation (AF) and Normal Sinus Rhythm (NSR)) obtained of Physionet database. The results show that these features discriminate arrhythmia from NSR subjects by p<;1E-6; CHF from NSR by p<;2E-3; AF from NSR by p<;4E-4; CHF from arrhythmia by p<;1E-2; CHF from AF by p<;5E-4; and arrhythmia from AF by p<;2E-3.