A method called Variational Modal Decomposition-Adaptive Entropy Threshold(VMD-AET)is proposed aiming at solving the problem that the electroencephalographic(EEG)signal in pre-seizure contains motion artifacts
which affects the prediction of epilepsy. Firstly
eight simulated motion states in the laboratory environment are designed in order to analyze the variation rule of EEG signals under different motion states. Secondly
the variational modal function(VMF)of different frequency band is obtained by VMD
and the components are solved and sorted by energy entropy. Finally
different entropy thresholds are used to remove the artifacts in the moving state and the optimal threshold is obtained by comparison
and the EEG signals without motion artifact are obtained. The motion artifact can be removed effectively by VMD-AET method via the software Matlab. Experiment results show that motion artifacts in each motion state can be removed effectively
and the artifact removal rate and signal-to-noise ratio reach their maximum during running. The motion artifacts in the EEG signals of epileptic patients are effectively removed. The artifact removal rate of EEG signals of the patients in pre-seizure is 5. 54%
and the signal-to-noise ratio increases to 10.35 dB. By comparing our method with the independent component algorithm(ICA)and the empirical mode decomposition(EMD)threshold value method
the VMD-AET method's artifact removal rate and signal-to-noise ratio are improved by 1.47% and 3.36 dB
respectively
which is suitable for the preprocessing of portable EEG system.
HUANG Shuai, DU Yunmei, LIANG Huiying, et al. Current research and development of prediction of epilepsy based on EEG [J]. China Digital Medicine, 2019, 14(3): 73-76.
ACHARYA U R, HAGIWARA Y, ADELI H. Automated seizure prediction [J]. Epilepsy and Behavior, 2018, 88: 251-261.
WEI Jinlian, HUANG Lihua. Research progress on seizure prediction [J]. Journal of Nursing and Rehabilitation, 2019, 18(6): 41-44.
ISSA M F, JUHASZ Z. Improved EOG artifact removal using wavelet enhanced independent component analysis [J]. Brain Sciences, 2019, 9(12): 355.
YANG Banghua, ZHANG Tao, ZHANG Yunyuan, et al. Removal of electrooculogram artifacts from electroencephalogram using canonical correlation analysis with ensemble empirical mode decomposition [J]. Cognitive Computation, 2017, 9(5): 626-633.
SÖZER A T, FIDAN C B. Emotiv epoc ile duragan hal görsel uyarilmii potansiyel temelli beyin bilgisayar arayüzü uygulamasi [J]. Bitlis Eren Üniversitesi Fen Bilimleri Dergisi, 2019, 8(1): 158-166.
DALY I, NICOLAOU N, NASUTO S J, et al. Automated artifact removal from the electroencephalogram: a comparative study [J]. Clinical EEG and Neuroscience, 2013, 44(4): 291-306.
CHEN Xun, LIU Aiping, CHEN Qiang, et al. Simultaneous ocular and muscle artifact removal from EEG data by exploiting diverse statistics [J]. Computers in Biology and Medicine, 2017, 88: 1-10.
ISLAM M S, EL-HAJJ A M, ALAWIEH H, et al. EEG mobility artifact removal for ambulatory epileptic seizure prediction applications [J]. Biomedical Signal Processing and Control, 2020, 55: 101638.
DE CLERCQ W, VERGULT A, VANRUMSTE B, et al. Canonical correlation analysis applied to remove muscle artifacts from the electroencephalogram [J]. IEEE Transactions on Biomedical Engineering, 2006, 53(12): 2583-2587.
CHEN Xun, LIU Aiping, PENG Hu, et al. A preliminary study of muscular artifact cancellation in single-channel EEG [J]. Sensors, 2014, 14(10): 18370-18389.
KIM B H, JO S. Real-time motion artifact detection and removal for ambulatory BCI [C]∥ Proceedings of the 3rd International Winter Conference on Brain-Computer Interface. Piscataway, NJ, USA: IEEE, 2015: 1-4.
OLIVEIRA A S, SCHLINK B R, HAIRSTON W D, et al. A channel rejection method for attenuating motion-related artifacts in EEG recordings during walking [J]. Frontiers in Neuroscience, 2017, 11: 225.
SALAZAR A. Independent component analysis(ICA): algorithms, applications and ambiguities [M]. New York, USA: Nova Science Publishers, 2000: 411-430.
TANG Guiji, WANG Xiaolong. Variational mode decomposition method and its application on incipient fault diagnosis of rolling bearing [J]. Journal of Vibration Engineering, 2016, 29(4): 638-648.
ZHANG Tao, CHEN Wanzhong, LI Mingyang. AR based quadratic feature extraction in the VMD domain for the automated seizure detection of EEG using random forest classifier [J]. Biomedical Signal Processing and Control, 2017, 31: 550-559.
DRAGOMIRETSKIY K, ZOSSO D. Variational mode decomposition [J]. IEEE Transactions on Signal Processing, 2014, 62(3): 531-544.
ZHANG Tao, HAN Zhiwu, CHEN Xiaojuan, et al. Assessing multi-layered nonlinear characteristics of ECG/EEG signal via adaptive kernel density estimation-based hierarchical entropies [J]. Biomedical Signal Processing and Control, 2021, 67: 102520.
YANG Lei, YANG Fan, HE Yan. An electroencephalogram artifacts removal algorithm for electroencephalogram signals based on sample entropy-complete ensemble empirical mode decomposition with adaptive noise [J]. Journal of Xi'an Jiaotong University, 2020, 54(8): 177-184.
ZHENG Jinde, CHEN Minjun, CHENG Junsheng, et al. Multiscale fuzzy entropy and its application in rolling bearing fault diagnosis [J]. Journal of Vibration Engineering, 2014, 27(1): 145-151.
ZHANG Chao, CHEN Jianjun, GUO Xun. Gear fault diagnosis method based on ensemble empirical mode decomposition energy entropy and support vector machine [J]. Journal of Central South University(Science and Technology), 2012, 43(3): 932-939.
ISLAM M K, RASTEGARNIA A, YANG Zhi. A wavelet-based artifact reduction from scalp EEG for epileptic seizure detection [J]. IEEE Journal of Biomedical and Health Informatics, 2016, 20(5): 1321-1332.