经穴电刺激诱发的脑-肌电信号相干性研究

EEG-EMG Coherence Induced by Acupoint Electrical Stimulation

为探索自主动作和穴位电刺激诱发的大脑皮层活动与肌肉收缩之间的功能耦合作用,设计穴位电刺激和自主动作两种实验模式,分别采集对应的脑电信号和表面肌电信号,对信号进行预处理得到纯净的诱发脑电和肌电信号.然后进行小波变换,获得信号的小波谱和小波交叉谱,计算小波相干系数,分析脑电和肌电信号的时-频相干特性.结果表明：穴位电刺激诱发的脑-肌电相干性主要集中在15~25 Hz信号频段,对应于大脑β节律;而自主动作下的脑-肌电相干性集中在30~36Hz频段,对应于大脑γ节律;不同导联的脑-肌电信号相干特性,表明穴位电刺激诱发的腕部肌肉动作与对侧大脑运动区相干性最强.该研究为运动功能康复和智能假肢开发奠定了基础.

To explore coupling function between cerebral cortex activity and muscle contractions under the voluntary movement and the acupoint electrical stimulation,experimental models of the electrical stimulation and voluntary movement were designed to collect signals of electroencephalogram（EEG）and electromyography（EMG）respectively,and to get the evoked signals by doing data preprocessing.Then,wavelet spectral and cross wavelet spectrum of those signals were obtained by Wavelet Transform,wavelet coherence coefficient was calculated,and time-frequency coherence characteristics of EEG and EMG were analyzed.It is shown that EEG-EMG coherence,induced by acupoint electrical stimulation,mainly concentrates on 15~25Hz signal spectrum,corresponding to theβrhythm of EEG.However,EEG-EMG coherence,under the voluntary movement,concentrates on 30~36Hz signal spectrum,corresponding to theγrhythm of EEG.The signal coherence from different leads of EEG and EMG signals shows that wrist muscle action has strongest coherence with the contralateral motor area of brain while induced by acupoint electrical stimulation.The research laid a solid foundation for motor function recovery and intelligent prosthetic development.