多通道脑电信号采集自适应滤波优化仿真

摘要

对脑电信号的采集过程自适应滤波,能够为神经管理科学实验研究提供更高质量的数据采集服务.多通道脑电信号的采集滤波,需要提取脑电信号的特征向量,调整自适应滤波器的权值系数,完成脑电信号采集自适应滤波.传统方法利用相似关系的滤波方法,对多通道脑电信号进行特征提取,但忽略了对滤波器权值系数,导致滤波效果不理想.提出基于小波变换的自适应滤波方法,借助计算机系统光标的左右指向,采集被试大脑想象左右方向所对应的多通道脑电信号;选取脑电信号中两个特殊频带的小波系数的平均能量作为特征向量,构建多通道脑电信号的AR模型,实现脑电信号特征向量的提取;计算信号的自适应滤波器输出,调整自适应滤波器的权值系数,完成对多通道脑电信号采集自适应滤波的优化.实验表明,所用方法能够实现多通道脑电信号采集的工频干扰自适应滤波,且选取5阶自适应滤波器的滤波效果最佳.%The aim of this article is to over defect of traditional adaptive filtering method for collection of multi-channel brain electrical signal,such as poor filtering effect.Based on wavelet transform,a new adaptive filtering method is proposed.By virtue of right and lefi orientation of cursor of computer system,multi-channel brain electrical signal corresponding to the examined brain imaging left-fight direction is collected.Average energy of wavelet coefficient of two special frequency bands in brain electrical signal is selected as characteristic vector.AR model of the multi-channel brain electrical signal is built to achieve extraction of the characteristic vector.Output of adaptive filter of the signal is calculated.Weight coefficient of the adaptive filter is adjusted.Thus,optimization of the adaptive filtering is completed.Simulation results show that the method can achieve the adaptive filtering of power frequency interference.Filtering effect of adaptive filter with five orders is optimal.