Generalized Bonhoeffer-van der Pol oscillator for modelling cardiac pulse: Preliminary results

This work presents an approach for modelling cardiac pulse from electrocardiographic signals (ECG). We explore the use of the Bonhoeffer-van der Pol (BVP) model-being a generalized version of the van der Pol oscillator - which, under proper parameters, is able to describe action potentials, and it can be then adapted to modelling normal cardiac pulse. Using basics of non-linear dynamics and some algebra, the BVP system response is estimated. To account for an adaptive response for every single heartbeat, we propose a parameter tuning method based on a heuristic search in order to yield responses that morphologically resemble real ECG. This aspect is important since heartbeats have intrinsically strong variability in terms of both shape and length. Experiments are carried out over real ECG from MIT-BIH arrhythmias database. We perform a bifurcation and phase portrait analysis to explore the relationship between non-linear dynamics features and pathology. Preliminary results provided here are promising showing some hints about the ability of non-linear systems modelling ECG to characterize heartbeats and facilitate the classification thereof, being latter very important for diagnosing purposes.