Applied Medical Informatics

Time Frequency Signal Analysis and Processing (TFSAP) have been proposed in order to analyse the signal in both the time and the frequency domains. Electroencephalography (EEG) as a timevarying frequency signal is an interesting field in which Time Frequency Distribution (TFD) could be used in order to visualize the simultaneous distributions of signal energy in different physiological and pathological brain states. Particularly, epileptic signals due to their great features of seizure activity are introduced as the most attractive research field among researchers. This study outlines an investigation on two main pathologic brain states including, pre-ictal activity and seizure activity compared to normal activity. Pseudo-Wigner -Ville and Choi-William distributions are used in order to visualize the energy content of signals in these states. Different segments of brain electrical activity are analyzed using these distributions. Finally, Renyi’s entropy as an important characteristic which offer insight towards the EEG signal processing has been extracted from TFDs. The results obtained indicate that Renyi’s entropy is a high-quality discriminative feature especially in alpha and delta sub-bands of the EEG signal.