
Application to biomedical signals 131
FIGURE 4.15: (SEE COLOR INSERT) From the bottom: signal, 2D time-
frequency energy distribution obtained by means of MP, the same distribution in
3D. Courtesy of P. Durka, from [Durka, 2003].
At the beginning of the seizure (20–40 s) the occurrence of epileptic spikes re-
sulted in a low value of D
2
; in time-frequency energy distribution it was reflected
by very broad-band structures of short duration. During the period of chaotic behav-
ior (60–80 s) characterized by flatness of the plot we can see random distribution
of time-frequency structures. Interesting is the period (150–170s) when the system
tends toward limit ...