Application of the nonlinear methods in pneumocardiogram signals

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Yılmaz N., Akıllı M., ÖZBEK M., ZEREN T., Akdeniz K. G.

Journal of Biological Physics, vol.46, no.2, pp.209-222, 2020 (SCI-Expanded, Scopus) identifier identifier

  • Publication Type: Article / Article
  • Volume: 46 Issue: 2
  • Publication Date: 2020
  • Doi Number: 10.1007/s10867-020-09549-2
  • Journal Name: Journal of Biological Physics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, CAB Abstracts, EMBASE, INSPEC, MEDLINE, Veterinary Science Database
  • Page Numbers: pp.209-222
  • Keywords: Boltzmann Gibbs entropy, Chaos, Maximum Lyapunov exponents, Normalized inner scalogram, Pneumocardiogram, Scale index, Wavelet transform
  • Open Archive Collection: AVESIS Open Access Collection
  • Manisa Celal Bayar University Affiliated: Yes

Abstract

In this work, the pneumocardiogram signals of nine rats were analysed by scale index, Boltzmann Gibbs entropy and maximum Lyapunov exponents. The scale index method, based on wavelet transform, was proposed for determining the degree of aperiodicity and chaos. It means that the scale index parameter is close to zero when the signal is periodic and has a value between zero and one when the signal is aperiodic. A new entropy calculation method by normalized inner scalogram was suggested very recently. In this work, we also used this method for the first time in an empirical data. We compared the both methods with maximum Lyapunov exponents and observed that using together the scale index and the entropy calculation method by normalized inner scalogram increases the reliability of the pneumocardiogram signal analysis. Thus, the analysis of the pneumocardiogram signals by those methods enables to compare periodical and/or nonlinear aspects for further understanding of dynamics of cardiorespiratory system.