基于EMD闪光视觉诱发电位的单次提取方法

探讨了基于EMD方法的单通道闪光视觉诱发电位(FVEP)信号的单次提取方法.应用EMD方法的自适应多分辨率特性,首先把单通道闪光视觉诱发电位信号进行EMD分解,然后根据FVEP的频率特征,选择对应的IMF分量进行重构,得到有效去噪后的FVEP信号,可实现FVEP信号的单次提取.与目前临床最常用的叠加平均方法比较,说明利用EMD方法单次提取的FVEP信号能够准确反映FVEP的典型特征信息,满足了临床应用要求.

Study on Single-Trial Extraction of FVEP Signal Based on Empirical Mode Decomposition Method

The single-trial extraction method of single-channel flash visual evoked potential(FVEP) signal based on empirical mode decomposition(EMD) has been studied.Based on the local feature time scale of a signal,a complex signal can be decomposed into the summary of some intrinsic mode functions(IMF) with EMD method.The frequency component of every IMF is not only related with analyzed frequency,but also changes with signal.EMD is of the self-adaptive multi-resolution characteristic.Based on the characteristic,the single-channel FVEP signal is first decomposed with EMD.Then based on the frequency feature of FVEP,the appropriate IMF components are selected to reconstruct.Finally,the de-noised FVEP signal can be obtained,and the single-trial extraction of FVEP is realized.Compared with the FVEP extraction results with ensemble average method used in clinical,the single-trial extraction results with EMD can reflect the classical feature information of FVEP and satisfy the demands for clinical application.