【作者】 张力；

【导师】 赵越；

【作者基本信息】 东北大学 ， 生物医学工程， 2014， 硕士

【摘要】 脑-机接口(brain-computer interface, BCI)是一种利用人脑生物电信号实现人脑与计算机或其他电子设备通讯和控制的系统。它正成为脑科学、计算机工程、生物医学工程及人机自动控制研究领域的一个研究热点。本文阐述了脑机接口的原理,给出了基于视觉诱发电位的脑计算机接口系统的方案,该方案的关键部分是刺激器的实现,它提供了用户利用脑电信号输入字符所需的刺激。本论文的主要工作及研究成果有以下几个方面：第一：作者通过Visual Studio 2010利用MFC编程设计了脑机接口视觉刺激器。为了保证目标图像的高速和平滑的显示,作者采用了DirectX技术；基于Windows精确定时,作者列举了毫秒级定时的方法,在实验的基础上,选取了多媒体定时器；经过查阅资料,使用WinIO函数库,成功地解决了并口输出。实测显示,视窗中的目标图像同时运动时,平滑稳定、无抖动现象,时间精度达到设计要求,实时向并口输出数据,该方案能有效地诱发出可识别的具有特征性的视觉诱发电位。第二：利用两台计算机和脑电信号采集系统建立了一个基于视觉诱发电位的脑机接口实验系统。本研究利用累加平均提取强噪声背景下视觉诱发电位的方法,可以有效地提高信噪比,但不能提取出显著的视觉诱发电位信号。课题组采用少量累加平均结合小波时频滤波,实验结果表明,大约只需十几次视觉刺激数据,就可以提取出波形特征显著的视觉诱发电位信号,有利于提高脑机接口的通讯准确性。第三：作者成功地利用刺激器与脑电采集系统开展了脑机接口实验。研究结果表明,当屏幕上有12个刺激模块,受试者注视其中任意位置的一个刺激模块时,均可能检测到相应的VEP信号。不同的颜色模块的闪烁或颜色交替变化均能引起视觉诱发电位信号,但所引起的VEP信号的波形形状及幅度存在一定的差异。其中,白色黑色模块的闪烁所引起的VEP信号幅度较大。当视觉刺激频率在4Hz左右变化时,所有受试者均能检测到比较明显的瞬态VEP信号。更多还原

【Abstract】 BCI is a system using human brain biological signals to achieve the human brain to a computer or other electronic devices communication and controlling. It is becoming a hot topic of brain science, computer engineering, biomedical engineering and research in the field of human-computer automatic control. In this article the author gives visual evoked potentials based brain computer interface systems solutions, a key part of the program is to realize the simulator, which provides user with the desired character EEG input.The main work of this thesis and the results of research the are:First, using computer software programming a computer monitor brain-computer interface design visual stimulator. According to the Windows precision settimer the author enumerated the method for the millisecond class to make the target image moves smoothly and stably. Second, the author use two computers and EEG acquisition system created a brain-computer interface based on visual evoked potentials experimental system. Third, the author has successfully carried out a brain-computer interface experiment.The results show that when the stimulation modules on the screen, one of the subjects watched module anywhere stimulation, may detect the respective VEP signals. Modules of different colors or color alternating flashes can cause visual evoked potential signals, but the shape and amplitude of the waveform caused by VEP signals there are some differences. Which, VEP amplitude of the signal flashing white black modules caused greater. When visual stimulation frequencies around 4Hz changes could be detected in all subjects more obvious transient VEP signals.更多还原