基于体感电刺激诱发P300的脑机接口

Electrical somatosensory based P300 for a brain-computer interface system

基于视听刺激诱发P300信号是目前脑机接口普遍使用的范式,然而众多病患存在视听功能障碍,无法由视听刺激获得稳定准确的P300信号,传统的P300脑机接口存在诸多局限性,因此,设计了一种以空间体感电刺激作为新范式的P300-脑机接口系统。实验采集了15名健康受试者注意不同手指电刺激时的脑电信号,仅对单一导联的数据进行分析处理,得到分类准确率和信息传输速率。结果显示,所有受试者可以成功诱发出P300特征信号,潜伏期在300ms附近;所有受试者的平均分类正确率达到77.96%±5.04%,高于随机水平(25%);信息传输速率最高可达15.97 bit/min。实验结果表明,采用基于空间位置的体感电刺激诱发P300的脑机接口系统,可以获得稳定的P300特征信号,是一种新的诱发模式;此外,仅采用一个导联的数据,即可达到较好的分类正确率和信息传输速率,方便用户使用。

P300 evoked by visual or auditory stimulation is a commonly used paradigm in Brain-computer interface （BCI）. However, accurate P300 signal by visual or auditory stimulus can not be obtained due to lots of patients whose vision or hearing are impaired. This brings several limitations in visual or auditory P300- BCIs due to disables. In this study, we apply spatial somatosensory electrical stimuli as a new paradigm for P300 BCI system. Fifteen subjects are required to focus on the electrical stimulation of different fingers, while a single-channel P300 signal is used to generate BCI for evaluation of classification accuracy and information transmission rate. Test results show that all participants are able to elicit a P300 wave with stable latencies around 300ms. Mean performance of classification accuracy reaches 77.96% ~： 5. 04% , that is much higher than chance lever （ 25% ）. The maximal information transfer rate （ITR） is 15.97 bit/min. Experiments prove that spatial somatosensory electrical stimuli can elicit a stable P300 as a new paradigm for BCI. In addition, the single-channel data analysis is capable of obtaining a satisfied performance in classification accuracy and information transfer rate, making it convenient for users.