摘要
当可使用频率有限时,基于稳态视觉诱发电位(SSVEP)的脑-机接口(BCI)系统所能呈现的目标数较少。为了有效地增加该目标数,该文提出了一种基于左右视野、使用两个频率闪烁块呈现目标的刺激方法。5名受试者参加了试验。用典型相关分析法处理数据,提取左右视野区与刺激对应的频率成分。离线正确率分析表明:4名受试目标识别率超过85%。采用该方法,在使用2个频率时,该系统所能呈现的目标个数提高了2倍。
Only a small number of targets can be presented when using limited frequencies in brain-computer interfaces(BCI) based on SSVEP(steady-state visual evoked potentials).A method was developed for simultaneous right-and-left field stimulation with two frequencies to acquire more targets when using a screen display as the stimulator in SSVEP-BCIs.Canonical correlation analysis(CCA) was applied to extract the frequency components of the right-and-left visual fields.Offline analyses of 5 subjects show that the final accuracy for four of the subjects was more than 85%.Thus,the method with two frequencies can recognize more than twice as many targets as conventional SSVEP-BCIs.
出处
《清华大学学报(自然科学版)》
EI
CAS
CSCD
北大核心
2009年第12期2013-2016,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金资助项目(30630022)
国家“八六三”高技术项目(2006AA01Z134)