Improving classification accuracy of motor imagery EEG signals via effective epochs

Brain computer interfaces (BCI) are systems which make it possible to use various electronic devices using only the signals produced in the brain. In order to ensure high performance of these systems, feature methods extracted from these signals and classifier methods applied to these signals are important With this study, we proposed a method to obtain high classification accuracy from EEG based BBA signals recorded on the motor imaginary with the extracted features in the active time segments. Features were obtained by applying the Hilbert Transform to the active time segments selected EEG signs and calculating the average of the derivatives of the signs. Features extracted from two-class motor imaginary Data Set la (Presented at the BC/ Competition 2003 competition) were analyzed by support vector machines, k-nearest neighborhood and linear discriminant analysis. Then the performance of the classifiers was compared. A high classification accuracy of 91.12% is calculated on the test dataset with support vector machines. This classification accuracy is 1706% higher than the classification accuracy obtained in the case of using all samples of a trial of the EEG signal. As a result, the proposed method increased the accuracy of classification in a remarkable amount and reduced computational complexity with the feature extraction methods and support vector machine classifier.