Title :
Extracting evoked potentials with the singularity detection technique
Author :
Zhang, Jiwu ; Zheng, Chongxun
Author_Institution :
Biomed. Eng. Inst., Xi´´an Jiaotong Univ., China
Abstract :
For a better and faster method of extracting EPs, we study the difference between the EP signal singularities and the EEG noise singularities. The ensemble-averaging operation is based on the fact that the EEG can be looked upon as white noise. The singularity detection (SD) technique that we discuss can adequately remove white noise from the signal. We found that there was a very large difference between the EP signal singularities and the EEG noise singularities. The local maxima of the wavelet-transform modulus provide enough information to analyze these singularities. We can extract the EP signal components from the EEG noise by selecting the wavelet-transform modulus maxima that correspond to the EP signal singularities. After removing the modulus maxima of the EEG noise fluctuations, we are able to reconstruct a denoised EP signal.
Keywords :
bioelectric potentials; electroencephalography; medical signal processing; signal detection; signal reconstruction; wavelet transforms; white noise; EEG noise fluctuations; EEG noise singularities; EP signal singularities; denoised EP signal; ensemble-averaging operation; evoked potential extraction; local maxima; singularity detection technique; wavelet-transform modulus; white noise; Adaptive filters; Biomedical engineering; Clinical diagnosis; Electroencephalography; Filtering; Information analysis; Wavelet analysis; Wavelet transforms; White noise; Wiener filter; Algorithms; Computer Simulation; Electroencephalography; Evoked Potentials, Somatosensory; Fourier Analysis; Image Processing, Computer-Assisted; Models, Neurological; Signal Processing, Computer-Assisted;
Journal_Title :
Engineering in Medicine and Biology Magazine, IEEE