Normal heartbeat series are nonchaotic, nonlinear, and multifractal: new evidence from semiparametric and parametric tests

Chaos. 2009 Jun;19(2):028503. doi: 10.1063/1.3152006.

Abstract

We present new evidence that normal heartbeat series are nonchaotic, nonlinear, and multifractal. In addition to considering the largest Lyapunov exponent and the correlation dimension, the results of the parametric and semiparametric estimation of the long memory parameter (long-range dependence) unambiguously reveal that the underlying process is nonstationary, multifractal, and has strong nonlinearity.

MeSH terms

  • Fractals
  • Heart Rate / physiology*
  • Humans
  • Models, Cardiovascular*
  • Nonlinear Dynamics