Effective and Extensible Feature Extraction Method Using Genetic Algorithm-Based Frequency-Domain Feature Search for Epileptic EEG Multi-classification

TL;DR

This paper introduces a genetic algorithm-based frequency-domain feature search (GAFDS) method for EEG analysis in epilepsy, improving feature extraction and classification accuracy with high extensibility and effectiveness.

Contribution

The paper presents a novel GAFDS method that enhances EEG feature extraction by combining frequency and nonlinear features, including instantaneous frequency, leading to improved classification performance.

Findings

Achieved up to 99% accuracy in two-class EEG classification.

Features show high independence and better inter/intra-class distance ratios.

GAFDS demonstrates good extensibility and effectiveness across classifiers.

Abstract

In this paper, a genetic algorithm-based frequency-domain feature search (GAFDS) method is proposed for the electroencephalogram (EEG) analysis of epilepsy. In this method, frequency-domain features are first searched and then combined with nonlinear features. Subsequently, these features are selected and optimized to classify EEG signals. The extracted features are analyzed experimentally. The features extracted by GAFDS show remarkable independence, and they are superior to the nonlinear features in terms of the ratio of inter-class distance and intra-class distance. Moreover, the proposed feature search method can additionally search for features of instantaneous frequency in a signal after Hilbert transformation. The classification results achieved using these features are reasonable, thus, GAFDS exhibits good extensibility. Multiple classic classifiers (i.e., $k$-nearest neighbor, linear discriminant analysis, decision tree, AdaBoost, multilayer perceptron, and Na\"ive Bayes) achieve good results by using the features generated by GAFDS method and the optimized selection. Specifically, the accuracies for the two-classification and three-classification problems may reach up to 99% and 97%, respectively. Results of several cross-validation experiments illustrate that GAFDS is effective in feature extraction for EEG classification. Therefore, the proposed feature selection and optimization model can improve classification accuracy.