Isolating gait-related movement artifacts in electroencephalography during human walking.
Isolating gait-related movement artifacts in electroencephalography during human walking.
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DOI：
10.1088/1741-2560/12/4/046022
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发表时间：
2015-08
影响因子：
4
通讯作者：
Ferris DP
中科院分区：
文献类型：
--
作者：
Kline JE;Huang HJ;Snyder KL;Ferris DP
高密度脑电(EEG)可以在真实世界的步行活动中提供对人脑功能的洞察。最近的一些研究使用脑电来表征行走过程中的大脑活动，但运动伪影和大脑皮层活动的相对贡献一直难以量化。我们的目标是表征在不同行走速度下由脑电电极记录的运动伪影，并测试伪影去除方法的有效性。我们还量化了脑电电极记录的运动伪影与头盔加速度计之间的相似性。我们使用了一种新颖的实验方法来分离和记录行走过程中的脑电电极运动伪影。我们使用非导电层(硅胶泳帽)阻断电生理信号，并使用涂有导电凝胶的假发模拟泳帽顶部的导电头皮。我们记录了9名年轻人在跑步机上以0.4-1.6m/S的速度行走的运动伪影脑电数据，然后测试了包括移动平均和基于小波的技术在内的运动伪影去除方法。用脑电电极记录的运动伪影在速度、对象和电极位置上有很大的不同。用脑电电极测量的运动伪影与头部加速度没有很好的相关性。所有测试的伪影去除方法都减弱了低频噪声，但并没有完全去除运动伪影。运动伪像数据中的频谱功率波动类似于之前发表的一些关于行走过程中的脑电研究的数据。我们的结果表明，在行走过程中记录的脑电数据可能包含大量的运动伪像：不能用头部加速来解释；不同速度、对象和通道的不同；以及无法使用传统信号处理方法去除。未来的研究应该集中在去除脑电运动伪影的更复杂的方法上，以推动这一领域的发展。
High-density electroencephelography (EEG) can provide insight into human brain function during real-world activities with walking. Some recent studies have used EEG to characterize brain activity during walking, but the relative contributions of movement artifact and electrocortical activity have been difficult to quantify. We aimed to characterize movement artifact recorded by EEG electrodes at a range of walking speeds and to test the efficacy of artifact removal methods. We also quantified the similarity between movement artifact recorded by EEG electrodes and a head-mounted accelerometer. We used a novel experimental method to isolate and record movement artifact with EEG electrodes during walking. We blocked electrophysiological signals using a nonconductive layer (silicone swim cap) and simulated an electrically conductive scalp on top of the swim cap using a wig coated with conductive gel. We recorded motion artifact EEG data from nine young human subjects walking on a treadmill at speeds from 0.4–1.6 m/s. We then tested artifact removal methods including moving average and wavelet-based techniques. Movement artifact recorded with EEG electrodes varied considerably, across speed, subject, and electrode location. The movement artifact measured with EEG electrodes did not correlate well with head acceleration. All of the tested artifact removal methods attenuated low-frequency noise but did not completely remove movement artifact. The spectral power fluctuations in the movement artifact data resembled data from some previously published studies of EEG during walking. Our results suggest that EEG data recorded during walking likely contains substantial movement artifact that: cannot be explained by head accelerations; varies across speed, subject, and channel; and cannot be removed using traditional signal processing methods. Future studies should focus on more sophisticated methods for removing of EEG movement artifact to advance the field.