title: New approach for visualization of relationships between RR and JT intervals.
abstract: This paper presents the concept of perfect matrices of Lagrange differences which are used to analyze relationships between RR and JT intervals during the bicycle ergometry exercise. The concept of the perfect matrix of Lagrange differences, its parameters, the construction of the load function and the corresponding optimization problem, the introduction of internal and external smoothing, embedding of the scalar parameter time series into the phase plane-all these computational techniques allow visualization of complex dynamical processes taking place in the cardiovascular system during the load and the recovery processes. Detailed analysis is performed with one person's RR and JT records only-but the presented techniques open new possibilities for novel interpretation of the dynamics of the cardiovascular system.
authors.affiliation: Research Group for Mathematical and Numerical Analysis of Dynamical Systems, Kaunas University of Technology, Kaunas, Lithuania.
authors.forename: Pranas
authors.initials: P
authors.lastname: Ziaukas
authors.affiliation: Prince Sultan Cardiac Center, Al Hasa, Al Hofuf, Saudi Arabia.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Alabdulgader
authors.affiliation: Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Alfonsas
authors.initials: A
authors.lastname: Vainoras
authors.affiliation: Research Group for Mathematical and Numerical Analysis of Dynamical Systems, Kaunas University of Technology, Kaunas, Lithuania.
authors.forename: Zenonas
authors.initials: Z
authors.lastname: Navickas
authors.affiliation: Research Group for Mathematical and Numerical Analysis of Dynamical Systems, Kaunas University of Technology, Kaunas, Lithuania.
authors.forename: Minvydas
authors.initials: M
authors.lastname: Ragulskis
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology; D004562:Electrocardiography / Q000379:methods; D015444:Exercise / Q000502:physiology*; D006321:Heart / Q000502:physiology*; D006801:Humans; D008297:Male; D013997:Time Factors