title: Facilitating joint chaos and fractal analysis of biosignals through nonlinear adaptive filtering.
abstract: BACKGROUND
  Chaos and random fractal theories are among the most important for fully characterizing nonlinear dynamics of complicated multiscale biosignals. Chaos analysis requires that signals be relatively noise-free and stationary, while fractal analysis demands signals to be non-rhythmic and scale-free.
  
  
  RESULTS
  To facilitate joint chaos and fractal analysis of biosignals, we present an adaptive algorithm, which: (1) can readily remove nonstationarities from the signal, (2) can more effectively reduce noise in the signals than linear filters, wavelet denoising, and chaos-based noise reduction techniques; (3) can readily decompose a multiscale biosignal into a series of intrinsically bandlimited functions; and (4) offers a new formulation of fractal and multifractal analysis that is better than existing methods when a biosignal contains a strong oscillatory component.
  
  
  CONCLUSIONS
  The presented approach is a valuable, versatile tool for the analysis of various types of biological signals. Its effectiveness is demonstrated by offering new important insights into brainwave dynamics and the very high accuracy in automatically detecting epileptic seizures from EEG signals.
authors.affiliation: PMB Intelligence LLC, West Lafayette, Indiana, United States of America. jbgao@pmbintelligence.com
authors.forename: Jianbo
authors.initials: J
authors.lastname: Gao
authors.forename: Jing
authors.initials: J
authors.lastname: Hu
authors.forename: Wen-wen
authors.initials: WW
authors.lastname: Tung
mesh_terms: D000465:Algorithms; D000818:Animals; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology; D017709:Fractals; D006801:Humans; D017711:Nonlinear Dynamics; D012815:Signal Processing, Computer-Assisted