• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2019, Vol. 55 ›› Issue (11): 28-35.doi: 10.3901/JME.2019.11.028

• 特邀专栏:共融机器人 • 上一篇    下一篇

基于改进共空间模式与视觉反馈的闭环脑机接口

任士鑫1,2, 王卫群1,2, 侯增广1,2, 陈霸东3, 石伟国1,2, 王佳星1,2, 梁旭1,2   

  1. 1. 中国科学院自动化研究所 北京 100190;
    2. 中国科学院大学 北京 100049;
    3. 西安交通大学人工智能与机器人研究所 西安 710049
  • 收稿日期:2018-10-15 修回日期:2019-01-24 出版日期:2019-06-05 发布日期:2019-06-05
  • 通讯作者: 王卫群(通信作者),男,1979年出生,博士,副研究员,硕士研究生导师。主要研究方向为康复机器人,人机交互控制,生理电信号处理。E-mail:weiqun.wang@ia.ac.cn
  • 作者简介:任士鑫,男,1993年出生,博士研究生。主要研究方向为康复机器人交互控制,脑机接口。E-mail:renshixin2015@ia.ac.cn;侯增广,男,1969年出生,博士,研究员,博士研究生导师。主要研究方向为机器人与智能系统,康复机器人与微创介入手术机器人。E-mail:zengguang.hou@ia.ac.cn;陈霸东,男,1974年出生,博士,教授,博士研究生导师。主要研究方向为信息论学习,信号处理及脑机接口。E-mail:chenbd@mail.xjtu.edu.cn;石伟国,男,1994年出生,硕士研究生。主要研究方向为康复机器人。E-mail:shiweiguo2017@ia.ac.cn;王佳星,女,1992年出生,博士研究生。主要研究方向为康复机器人。E-mail:wangjiaxing2016@ia.ac.cn;梁旭,男,1991年出生,博士研究生。主要研究方向为康复机器人。E-mail:liangxu2013@ia.ac.cn
  • 基金资助:
    国家自然科学基金(91648208,91848110)、北京市自然科学基金(3171001,L172050)和中国科学院战略性先导科技专项(B类,XDB32000000)资助项目。

Closed Loop Brain Computer Interface Based on Improved Common Spatial Patterns and Visual Feedback

REN Shixin1,2, WANG Weiqun1,2, HOU Zengguang1,2, CHEN Badong3, SHI Weiguo1,2, WANG Jiaxing1,2, LIANG Xu1,2   

  1. 1. Institute of Automation Chinese Academy of Sciences, Beijing 100190;
    2. University of Chinese Academy of Sciences, Beijing 100049;
    3. Institute of Artificial Intelligence and Robotics Xi'an Jiaotong University, Xi'an 710049
  • Received:2018-10-15 Revised:2019-01-24 Online:2019-06-05 Published:2019-06-05

摘要: 为提高脑卒中等神经损伤患者在下肢康复训练过程中的主动参与度,设计了基于人体下肢运动想象与视觉反馈的在线闭环脑机接口,并建立了基于互相关熵诱导度量与子频带分析的改进共空间模式算法,提高人体下肢运动意图的识别率。针对运动想象脑电信号信噪比低和难以精确识别等问题,在传统共空间模式算法基础上,利用互相关熵诱导度量准则改进其目标函数,实现了目标函数中距离项属性的动态调整,降低对噪声的敏感性,提高算法鲁棒性;利用脑电信号不同频段蕴含信息不同的特点,使用9个子频带滤波器对信号进行滤波,对每个子频带信号分别提取特征,并进行特征融合,建立基于互相关熵诱导度量与子频带分析的改进共空间模式算法。其次,基于人体下肢运动想象的脑控试验范式,收集下肢运动想象(空想、脚动和腿动)的脑电数据,采用支持向量机(SVM)建立分类模型,优化设计模型参数。在上述研究基础上,建立了以改进共空间模式为特征提取算法,SVM为分类器的脑机接口。进而,在被试执行运动想象的同时,通过虚拟现实场景中虚拟人物的肢体动作给予用户视觉反馈,构建了闭环的脑机交互系统。通过试验验证了改进共空间模式算法的有效性和闭环脑机接口的可行性,初步实现了闭环脑机交互接口。

关键词: 共空间模式, 互相关熵诱导度量, 脑机接口, 运动想象

Abstract: In order to improve the active participation of patients with stroke or nerve injury in the lower limb rehabilitation training, an on-line closed loop brain computer interface is designed based on human lower limb motor imagery and visual feedback. And an improved common spatial pattern algorithm, which based on the correntropy induced metric and sub-frequency band analysis, is established to improve the recognition rate of the motor intention. Due to the low signal noise ratio and classification accuracy of the motor imagery EEG signals, correntropy induced metric is adopted to improve the objective function of the traditional common spatial patterns (CSP). The distance term of the objective function can be adjusted dynamically to alleviate the negative effects of noise. Because the different frequency band signals have different information, nine sub-frequency bandpass filters are used to filter the signal. And the features extracted from each sub-band signal are fused. Therefore, the improved common spatial pattern algorithm based on the correntropy induced metric and sub-frequency band analysis is established. Then, based on the brain control experiment paradigm of human lower limb motor imagery, EEG data of lower limbs motor imagery (idle, foot and leg) are collected. Support vector machine (SVM) is optimized as a classification model for the motor imagery. Based on the study above, a brain computer interface based on improved common spatial pattern algorithm and SVM is built. When participant images the movements, the user's visual feedback is given to the user through the body movements of the virtual character in the virtual reality scene, and a closed loop brain computer interaction system is constructed. Experiments verified the effectiveness of the improved common space algorithm and the feasibility of closed-loop brain computer interface, and the closed loop interaction between the brain and computer is achieved initially.

Key words: brain-computer interface, common spatial patterns, correntropy induced metric, motor imagery

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