Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Singapore 599489, Singapore.
Int J Neural Syst. 2011 Oct;21(5):403-14. doi: 10.1142/S0129065711002912.
The unpredictability of the occurrence of epileptic seizures makes it difficult to detect and treat this condition effectively. An automatic system that characterizes epileptic activities in EEG signals would allow patients or the people near them to take appropriate precautions, would allow clinicians to better manage the condition, and could provide more insight into these phenomena thereby revealing important clinical information. Various methods have been proposed to detect epileptic activity in EEG recordings. Because of the nonlinear and dynamic nature of EEG signals, the use of nonlinear Higher Order Spectra (HOS) features is a seemingly promising approach. This paper presents the methodology employed to extract HOS features (specifically, cumulants) from normal, interictal, and epileptic EEG segments and to use significant features in classifiers for the detection of these three classes. In this work, 300 sets of EEG data belonging to the three classes were used for feature extraction and classifier development and evaluation. The results show that the HOS based measures have unique ranges for the different classes with high confidence level (p-value < 0.0001). On evaluating several classifiers with the significant features, it was observed that the Support Vector Machine (SVM) presented a high detection accuracy of 98.5% thereby establishing the possibility of effective EEG segment classification using the proposed technique.
癫痫发作的不可预测性使得有效检测和治疗这种疾病变得困难。一个能够对 EEG 信号中的癫痫活动进行特征描述的自动系统将允许患者或其身边的人采取适当的预防措施,使临床医生能够更好地管理病情,并能深入了解这些现象,从而揭示重要的临床信息。已经提出了各种方法来检测 EEG 记录中的癫痫活动。由于 EEG 信号的非线性和动态特性,使用非线性高阶谱(HOS)特征似乎是一种很有前途的方法。本文介绍了从正常、发作间期和癫痫 EEG 段中提取 HOS 特征(特别是累积量)的方法,并使用分类器中的显著特征来检测这三种类型。在这项工作中,使用了 300 组属于这三种类型的 EEG 数据进行特征提取和分类器的开发和评估。结果表明,基于 HOS 的度量具有不同类别的独特范围,置信水平高(p 值<0.0001)。通过对几种具有显著特征的分类器进行评估,观察到支持向量机(SVM)的检测准确率达到了 98.5%,从而证明了使用所提出的技术对 EEG 段进行有效分类的可能性。