Distinguishing Epileptiform Discharges From Normal Electroencephalograms Using Scale-Dependent Lyapunov Exponent

Frontiers in Bioengineering and Biotechnology

卷:8

Bo Xu²  Jianbo Gao³  Qiong Li⁴  Qi Huang⁵  Yuan Wu⁵ 

[1] Center for Geodata and Analysis, Faculty of Geographical Science, Beijing Normal University, Beijing, China;

[2] Institute of Automation, Chinese Academy of Sciences, Beijing, China;

[3] International College, Guangxi University, Nanning, China;

[4] School of Computer, Electronics and Information, Guangxi University, Nanning, China;

[5] The First Affiliated Hospital of Guangxi Medical University, Nanning, China;

关键词: EEG;    epileptiform discharges;    power spectral density (PSD);    scale-dependent Lyapunov exponent (SDLE);    random forest classifier;    support vector machine (SVM);   

DOI  :  10.3389/fbioe.2020.01006

来源: DOAJ

【 摘 要 】

Epileptiform discharges are of fundamental importance in understanding the physiology of epilepsy. To aid in the clinical diagnosis, classification, prognosis, and treatment of epilepsy, it is important to develop automated computer programs to distinguish epileptiform discharges from normal electroencephalogram (EEG). This is a challenging task as clinically used scalp EEG often contains a lot of noise and motion artifacts. The challenge is even greater if one wishes to develop explainable rather than black-box based approaches. To take on this challenge, we propose to use a multiscale complexity measure, the scale-dependent Lyapunov exponent (SDLE). We analyzed 640 multi-channel EEG segments, each 4 s long. Among these segments, 540 are short epileptiform discharges, and 100 are from healthy controls. We found that features from SDLE were very effective in distinguishing epileptiform discharges from normal EEG. Using Random Forest Classifier (RF) and Support Vector Machines (SVM), the proposed approach with different features from SDLE robustly achieves an accuracy exceeding 99% in distinguishing epileptiform discharges from normal control ones. A single parameter, which is the ratio of the spectral energy of EEG signals and the SDLE and quantifies the regularity or predictability of the EEG signals, is introduced to better understand the high accuracy in the classification. It is found that this regularity is considerably greater for epileptiform discharges than for normal controls. Robustly having high accuracy in distinguishing epileptiform discharges from normal controls irrespective of which classification scheme being used, the proposed approach has the potential to be used widely in a clinical setting.

【 授权许可】

Unknown