Removal of Ocular Artifacts in EEG Using Deep Learning

TL;DR

This paper introduces a novel deep learning approach using BiLSTM and wavelet synchrosqueezed transform for effective ocular artifact removal in EEG signals, outperforming traditional methods.

Contribution

The study develops a new BiLSTM-based deep learning model combined with WSST for ocular artifact removal, creating a benchmark dataset and demonstrating superior performance over existing methods.

Findings

WSST-Net achieved an average MSE of 0.3066.

The proposed method outperforms traditional TF and raw signal approaches.

The approach surpasses many existing ocular artifact removal techniques.

Abstract

EEG signals are complex and low-frequency signals. Therefore, they are easily influenced by external factors. EEG artifact removal is crucial in neuroscience because artifacts have a significant impact on the results of EEG analysis. The removal of ocular artifacts is the most challenging among these artifacts. In this study, a novel ocular artifact removal method is presented by developing bidirectional long-short term memory (BiLSTM)-based deep learning (DL) models. We created a benchmarking dataset to train and test proposed DL models by combining the EEGdenoiseNet and DEAP datasets. We also augmented the data by contaminating ground-truth clean EEG signals with EOG at various SNR levels. The BiLSTM network is then fed to features extracted from augmented signals using highly-localized time-frequency (TF) coefficients obtained by wavelet synchrosqueezed transform (WSST). We also compare the WSST-based DL model results with traditional TF analysis (TFA) methods namely short-time Fourier transformation (STFT) and continuous wavelet transform (CWT) as well as augmented raw signals. The best average MSE value of 0.3066 was obtained by the first time-proposed BiLSTM-based WSST-Net model. Our results demonstrated the WSST-Net model significantly improves artifact removal performance compared to traditional TF and raw signal methods. Also, the proposed EOG removal approach reveals that it outperforms many conventional and DL-based ocular artifact removal methods in the literature.