IEEE Trans Neural Syst Rehabil Eng. 2017 Nov;25(11):2146-2156. doi: 10.1109/TNSRE.2017.2697920. Epub 2017 Apr 25.
This paper proposes a novel patient-specific real-time automatic epileptic seizure onset detection, using both scalp and intracranial electroencephalogram (EEG). The proposed technique obtains harmonic multiresolution and self-similarity-based fractal features from EEG for robust seizure onset detection. A fast wavelet decomposition method, known as harmonic wavelet packet transform (HWPT), is computed based on Fourier transform to achieve higher frequency resolutions without recursive calculations. Similarly, fractal dimension (FD) estimates are obtained to capture self-similar repetitive patterns in the EEG signal. Both FD and HWPT energy features across all EEG channels at each epoch are organized following the spatial information due to electrode placement on the skull. The final feature vector combines feature configurations of each epoch within the specified moving window to reflect the temporal information of EEG. Finally, relevance vector machine is used to classify the feature vectors due to its efficiency in classifying sparse, yet high-dimensional data sets. The algorithm is evaluated using two publicly available long-term scalp EEG (data set A) and short-term intracranial and scalp EEG (data set B) databases. The proposed algorithm is effective in seizure onset detection with 96% sensitivity, 0.1 per hour median false detection rate, and 1.89 s average detection latency, respectively. Results obtained from analyzing the short-term data offer 99.8% classification accuracy. These results demonstrate that the proposed method is effective with both short- and long-term EEG signal analyzes recorded with either scalp or intracranial modes, respectively. Finally, the use of less computationally intensive feature extraction techniques enables faster seizure onset detection when compared with similar techniques in the literature, indicating potential usage in real-time applications.
本文提出了一种新颖的基于头皮和颅内脑电图(EEG)的患者特定实时自动癫痫发作起始检测方法。所提出的技术从 EEG 中获取基于谐波多分辨率和自相似性的分形特征,以进行稳健的发作起始检测。快速小波分解方法,称为谐波小波包变换(HWPT),是基于傅里叶变换计算的,无需递归计算即可实现更高的频率分辨率。类似地,分形维数(FD)估计用于捕获 EEG 信号中的自相似重复模式。在每个时期,所有 EEG 通道的 FD 和 HWPT 能量特征都根据颅骨上的电极位置组织起来,以获取空间信息。最终的特征向量组合了指定移动窗口内每个时期的特征配置,以反映 EEG 的时间信息。最后,由于其在分类稀疏但高维数据集方面的效率,使用相关向量机对特征向量进行分类。该算法使用两个公开可用的长期头皮 EEG(数据集 A)和短期颅内和头皮 EEG(数据集 B)数据库进行评估。该算法在发作起始检测方面非常有效,灵敏度为 96%,中位数假阳性率为 0.1 次/小时,平均检测潜伏期为 1.89 秒。从分析短期数据中获得的结果提供了 99.8%的分类准确性。这些结果表明,该方法分别使用头皮或颅内模式记录的短期和长期 EEG 信号分析都非常有效。最后,与文献中的类似技术相比,使用计算强度较低的特征提取技术可以实现更快的发作起始检测,表明其在实时应用中有潜在的用途。