Abstract
The embedding dimension of normal and epileptic electroencephalogram (EEG) time series is analyzed by two different methods, Cao's method and differential entropy method respectively. The results of the two methods indicate consistently that the embedding dimension of EEG signals during seizure changes and becomes different from that of normal EEG signals, and the embedding dimension varies intensively during seizure, whereas the embedding dimension of normal EEG signals keeps stable basically. The embedding dimension results also reflect the variation of freedom degree of human brain nonlinear dynamic system (NDS) during seizure. In addition, it is found based on the results of Cao's method that normal EEG signals are of some degree of randomness, whereas epileptic EEG signals has determinism.
