V Krishnaveni et al 2006 J. Neural Eng. 3 338 doi:10.1088/1741-2560/3/4/011
V Krishnaveni1, S Jayaraman1, L Anitha1 and K Ramadoss2
Show affiliationsElectroencephalogram (EEG) gives researchers a non-invasive way to record cerebral activity. It is a valuable tool that helps clinicians to diagnose various neurological disorders and brain diseases. Blinking or moving the eyes produces large electrical potential around the eyes known as electrooculogram. It is a non-cortical activity which spreads across the scalp and contaminates the EEG recordings. These contaminating potentials are called ocular artifacts (OAs). Rejecting contaminated trials causes substantial data loss, and restricting eye movements/blinks limits the possible experimental designs and may affect the cognitive processes under investigation. In this paper, a nonlinear time-scale adaptive denoising system based on a wavelet shrinkage scheme has been used for removing OAs from EEG. The time-scale adaptive algorithm is based on Stein's unbiased risk estimate (SURE) and a soft-like thresholding function which searches for optimal thresholds using a gradient based adaptive algorithm is used. Denoising EEG with the proposed algorithm yields better results in terms of ocular artifact reduction and retention of background EEG activity compared to non-adaptive thresholding methods and the JADE algorithm.
87.80.-y Biophysical techniques (research methods)
87.19.R- Mechanical and electrical properties of tissues and organs
Issue 4 (December 2006)
Received 10 January 2006, accepted for publication 27 October 2006
Published 23 November 2006
V Krishnaveni et al 2006 J. Neural Eng. 3 338
V V Pavlov 2006 Bioinspir. Biomim. 1 31
Lyndon Evans and Philip Bryant 2008 JINST 3 S08001
C Wochnowski et al 2005 J. Opt. A: Pure Appl. Opt. 7 493
R Garcia Diaz et al 2005 New J. Phys. 7 256
Yanga R. Fernández et al. 2003 The Astronomical Journal 126 1563
Umut Gürsoy et al JHEP12(2009)056
F Pistolesi and Rosario Fazio 2006 New J. Phys. 8 113
W S Chu et al 2009 New J. Phys. 11 083005
Jonathan Pumplin et al JHEP07(2002)012