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双人肢体协作动作运动想象脑电的ERD/ERS特征分析 被引量:2
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作者 姚树璋 徐佳琳 +4 位作者 左国坤 黄志权 李寒 盛俊鹏 连士东 《北京生物医学工程》 2023年第4期331-340,共10页
目的基于运动想象(motor imagery,MI)的脑机接口(brain computer interface,BCI)一般采用基于单人肢体动作的MI任务范式,诱发的事件相关去同步/同步(event-related desychronization/synchronization,ERD/ERS)模式及对应的可辨识思维类... 目的基于运动想象(motor imagery,MI)的脑机接口(brain computer interface,BCI)一般采用基于单人肢体动作的MI任务范式,诱发的事件相关去同步/同步(event-related desychronization/synchronization,ERD/ERS)模式及对应的可辨识思维类别数较为有限,无法满足BCI对外多指令控制。为此,本文在单人肢体动作MI的基础上引入双人肢体协作动作MI,探索双人肢体协作动作MI的脑电(electroencephalograph,EEG)信号的多脑区ERD/ERS特征。方法采用自回归模型功率谱估计和事件相关谱扰动方法,对被试者执行单人左/右手动作MI、双人左/右手协作动作MI的EEG数据,进行频率-空间-时间特性对比分析与研究。结果区别于单人左/右手动作MI,双人左/右手协作动作MI的EEG信号在大脑额叶区出现ERD特征,在感觉运动皮质区出现ERD、ERS特征,特征的频带更宽;感觉运动皮质区的ERD特征出现时间较晚、持续时间更长,且ERD、ERS特征的对比度更大。结论在相同肢体部位的前提下,双人肢体协作动作MI过程有可能增加BCI的思维类别数,且其EEG特征更易辨识。 展开更多
关键词 脑机接口 运动想象 双人肢体协作动作 脑电信号 事件相关去同步/同步
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一种运动想象脑电分类算法的研究 被引量:2
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作者 刘伯强 张振旺 +2 位作者 刘忠国 高均波 于兰兰 《生物医学工程研究》 2007年第1期20-23,32,共5页
为了解决脑机接口(BCI)中不同意识任务下脑电信号分类问题,针对运动想象脑电(EEG)的事件相关去同步/同步(ERD/ERS)现象,提出一种基于支持向量机(SVM)的实用分类算法。该算法首先对脑电信号进行滤波,获得对运动想象比较敏感的频段,对滤... 为了解决脑机接口(BCI)中不同意识任务下脑电信号分类问题,针对运动想象脑电(EEG)的事件相关去同步/同步(ERD/ERS)现象,提出一种基于支持向量机(SVM)的实用分类算法。该算法首先对脑电信号进行滤波,获得对运动想象比较敏感的频段,对滤波后的脑电信号,通过去均值减小由于均值不同所造成的误差,然后,再提取基于ERD/ERS的脑电能量场强特征,对提取的特征,运用支持向量机(SVM)进行分类,得到了满意的效果。结果表明,此方法可为脑机接口技术的应用提供有效的手段。 展开更多
关键词 运动想象 脑机接口 事件相关同步/去同步 能量场强 支持向量机
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Time-Frequency Analysis of EEG Signals Evoked by Voluntary, Stimulated and Imaginary Motions
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作者 明东 李南南 +6 位作者 付安爽 徐瑞 邱爽 徐强 周鹏 张力新 万柏坤 《Transactions of Tianjin University》 EI CAS 2014年第3期210-214,共5页
In order to investigate the characteristics of sensorimotor cortex during motor execution(ME), voluntary, stimulated and imaginary finger flexions were performed by ten volunteer subjects. Electroencephalogram(EEG) da... In order to investigate the characteristics of sensorimotor cortex during motor execution(ME), voluntary, stimulated and imaginary finger flexions were performed by ten volunteer subjects. Electroencephalogram(EEG) data were recorded according to the modified 10-20 International EEG System. The patterns were compared by the analysis of the motion-evoked EEG signals focusing on the contralateral(C3) and ipsilateral(C4) channels for hemispheric differences. The EEG energy distributions at alpha(8—13 Hz), beta(14—30 Hz) and gamma(30—50 Hz) bands were computed by wavelet transform(WT) and compared by the analysis of variance(ANOVA). The timefrequency(TF) analysis indicated that there existed a contralateral dominance of alpha post-movement event-related synchronization(ERS) pattern during the voluntary task, and that the energy of alpha band increased in the ipsilateral area during the stimulated(median nerve of wrist) task. Besides, the contralateral alpha and beta event-related desynchronization(ERD) patterns were observed in both stimulated and imaginary tasks. Another significant difference was found in the mean power values of gamma band(p<0.01)between the imaginary and other tasks. The results show that significant hemispheric differences such as alpha and beta band EEG energy distributions and TF changing phenomena(ERS/ERD) were found between C3 and C4 areas during all of the three patterns. The largest energy distribution was always at the alpha band for each task. 展开更多
关键词 ELECTROENCEPHALOGRAM motor execution wavelet transform time-frequency analysis analysis of vari-ance event-related synchronization event-related desynchronization
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