Estimation of parameter kmax in fractal analysis of rat brain activity.
We recorded electrocortical activity in anesthetized rats and constructed k(max) new self-similar time series, applying Higuchi's algorithm. The aim of this study was to estimate value of the parameter k(max) in order to obtain fractal dimension values as an optimum measure of biosignal change. After our analysis, electrocortical activity recordings resulted in a family of curves f(k(max)). Three regions could be distinguished 2 < or = k(max) < 8, with a U-shape; 8 < or = k(max) < or = 30, with a steeper quasilinear increase; and k(max) > or = 30, with a smaller slope quasilinear increase. We suggest the optimum region for k(max): 8 < k(max) < 18, specifically k(max) = 8.
Spasić
Sladjana
S
Center for Multidisciplinary Studies, University of Belgrade, Serbia and Montenegro. sladjana@ibiss.bg.ac.yu
Kalauzi
Aleksandar
A
Culić
Milka
M
Grbić
Gordana
G
Martać
Ljiljana
L
D000465:Algorithms; D000758:Anesthesia; D000818:Animals; D001930:Brain Injuries / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D017709:Fractals; D051381:Rats; D017208:Rats, Wistar; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors