Karotid Atardamar Doppler Sinyalleri Üzerinde En Büyük Lyapunov Üsteli ve İlinti Boyutu Hesabı

Abstract

Chaos theory or nonlinear analysis techniques have wide application areas on the physiological systems as in other fields. In this study the Largest Lyapunov Exponent (LLE) and Correlation Dimension (CD) calculations were performed for investigating the chaotic Dynamics of blood flow in the vessel on the Doppler signals taken from 25 healthy, 9 mild and serious degree stenosed carotid artery subjects. During the LLE calculations divergence of nearest neighboring trajectories in the phase space has been determined using Euclidean distance. The Grassberger-Procaccia algorithm was used for CD calculations. The value of correlation dimension obtained at the determined embedding dimension is used as CD . As a result, the calculalted LLE and CD values for stenosed carotid artery Doppler signals have been found as statistically high compare with the values that are belonging to healthy subjects ( p<0.00005).