Unsupervised Seizure Identification Using EMD. The classification of the calculated weighted frequencies by a supervised clustering using the Euclidian distance. Every point holds the information about the weighted frequencies of the first four IMF of an EMD processed EEG signal. Two different groups of points are illustrated; the first group (circles) indicates healthy EEG. The second group (stars) indicates seizure EEG. Asterisks indicate two different centres of group. The lower one is related to the seizure group.