IEEE Trans Biomed Eng. 2021 Oct;68(10):3087-3097. doi: 10.1109/TBME.2021.3064794. Epub 2021 Sep 20.
This article shows the interest in deep learning techniques to detect motor imagery (MI) from raw electroencephalographic (EEG) signals when a functional electrical stimulation is added or not. Impacts of electrode montages and bandwidth are also reported. The perspective of this work is to improve the detection of intraoperative awareness during general anesthesia.
Various architectures of EEGNet were investigated to optimize MI detection. They have been compared to the state-of-the-art classifiers in Brain-Computer Interfaces (based on Riemannian geometry, linear discriminant analysis), and other deep learning architectures (deep convolution network, shallow convolutional network). EEG data were measured from 22 participants performing motor imagery with and without median nerve stimulation.
The proposed architecture of EEGNet reaches the best classification accuracy (83.2%) and false-positive rate (FPR 19.0%) for a setup with only six electrodes over the motor cortex and frontal lobe and for an extended 4-38 Hz EEG frequency range while the subject is being stimulated via a median nerve. Configurations with a larger number of electrodes result in higher accuracy (94.5%) and FPR (6.1%) for 128 electrodes (and respectively 88.0% and 12.9% for 13 electrodes).
The present work demonstrates that using an extended EEG frequency band and a modified EEGNet deep neural network increases the accuracy of MI detection when used with as few as 6 electrodes which include frontal channels.
The proposed method contributes to the development of Brain-Computer Interface systems based on MI detection from EEG.
本文展示了深度学习技术在添加或不添加功能性电刺激时从原始脑电图(EEG)信号中检测运动想象(MI)的应用。还报告了电极组合和带宽的影响。这项工作的目的是提高全身麻醉期间术中意识的检测能力。
研究了各种 EEGNet 架构以优化 MI 检测。它们与脑机接口中的最新分类器(基于黎曼几何、线性判别分析)以及其他深度学习架构(深度卷积网络、浅层卷积网络)进行了比较。EEG 数据是从 22 名参与者在进行运动想象时(有或没有正中神经刺激)测量的。
提出的 EEGNet 架构在仅使用 6 个电极置于运动皮层和额叶上,并在扩展的 4-38 Hz EEG 频率范围内,同时通过正中神经刺激受试者时,达到了最佳的分类准确率(83.2%)和假阳性率(FPR 19.0%)。当使用更多电极(128 个电极)时,配置的准确性更高(94.5%)和假阳性率(6.1%),而当使用 13 个电极时,准确性为 88.0%,假阳性率为 12.9%。
本研究表明,使用扩展的 EEG 频带和修改后的 EEGNet 深度神经网络,在使用包括额叶通道在内的少至 6 个电极时,可提高 MI 检测的准确性。
所提出的方法为基于 EEG 的 MI 检测的脑机接口系统的发展做出了贡献。