Xiaochen Liu1 • Lingli Hu2 • Chenglin Xu3 • Shuai Xu2 • Shuang Wang2 • Zhong Chen3,4 • Jizhong Shen1

1 College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China

2 School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou 310009, China

3 College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China 4 College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China

Abstract

As an important promising biomarker, high frequency oscillations (HFOs) can be used to track epileptic activity and localize epileptogenic zones. However, visual marking of HFOs from a large amount of intracranial electroencephalogram (iEEG) data requires a great deal of time and effort from researchers, and is also very dependent on visual features and easily influenced by subjective factors. Therefore, we proposed an automatic epileptic HFO detection method based on visual features and non-intuitive multi-domain features. To eliminate the interference of continuous oscillatory activity in detected sporadic short HFO events, the iEEG signals adjacent to the detected events were set as the neighboring environmental range while the number of oscillations and the peak–valley differences were calculated as the environmental reference features. The proposed method was developed as a MatLab-based HFO detector to automatically detect HFOs in multi-channel, long-distance iEEG signals. The performance of our detector was evaluated on iEEG recordings from epileptic mice and patients with intractable epilepsy. More than 90% of the HFO events detected by this method were confirmed by experts, while the average missed-detection rate was < 10%. Compared with recent related research, the proposed method achieved a synchronous improvement of sensitivity and specificity, and a balance between low false-alarm rate and high detection rate. Detection results demonstrated that the proposed method performs well in sensitivity, specificity, and precision. As an auxiliary tool, our detector can greatly improve the efficiency of clinical experts in inspecting HFO events during the diagnosis and treatment of epilepsy.

Keywords

Epilepsy; HFO; Automatic detection; Combined features

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