视觉P300脑机接口中的SOA扰动现象  

SOA Perturbation in Visual P300 Brain Computer Interfaces

作　　者：邱天爽[1] 马征[1] 

机构地区：[1]大连理工大学生物医学工程系,大连116024

出　　处：《数据采集与处理》2013年第5期539-545,共7页Journal of Data Acquisition and Processing

基　　金：国家自然科学基金(81241059;61172108;61139001)资助项目;国家科技支撑计划(2012BAJ18B06)资助项目

摘　　要：异步操控性是脑机接口走向实际应用的关键技术之一。其关键点在于寻找一种可有效区分脑机接口工作状态和空闲状态的指标。建立了针对P300脑机接口的刺激起始异步(SOA)扰动模型,在仿真实验和实测数据中观察到SOA扰动谱线,并根据所提出的模型给出了合理解释。研究了SOA扰动的频域特性,结果表明,当SOA位于220ms附近时,SOA扰动的强度最大,而当SOA低于150ms时,SOA扰动强度将急剧减小。同时SOA扰动所具有的锁相性使得可以通过时域相干平均法进一步提高信噪比。SOA扰动可作为脑机接口处于工作状态的标志,为异步脑机接口的实现提供了一种新的研究思路。Asynchronous operating performance is one of the vital factors towards the practical use of brain computer interfaces （BCIs）.The key point is to find an indicator from brain activities that can effectively distinguish between control states and non-control states of the BCI system.A stimulus onset asynchrony （SOA） perturbation analysis model is built for the P300 BCI.Spectral lines of the SOA perturbation are observed in both the simulation experiment and real experiments,which can be explained by the current analysis model.It turns out that the strength of the SOA perturbation is largest when SOA is around 220 ms,but it decreases dramatically when SOA becomes lower than 150 ms.The phase-locking property of the SOA perturbation can be used to improve its signal-to-noise ratio.The SOA perturbation can be used as an asynchronous indicator of the BCI system and it gives a new direction for the implementation of asynchronous BCIs.

关 键 词：脑机接口 SOA扰动 异步BCI P300 Speller 

分 类 号：R318[医药卫生—生物医学工程] TN911.72[医药卫生—基础医学]