Noise reduction in rhythmic and multitrial biosignals with applications to event-related potentials

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Title Noise reduction in rhythmic and multitrial biosignals with applications to event-related potentials
Author Celka, Patrick; Le, Khoa Nguyen; Cutmore, Timothy
Journal Name IEEE Transactions on Biomedical Engineering
Year Published 2008
Place of publication USA
Publisher IEEE
Abstract A new noise reduction algorithm is presented for signals displaying repeated patterns or multiple trials. Each pattern is stored in a matrix, forming a set of events, which is termed multievent signal. Each event is considered as an affine transform of a basic template signal that allows for time scaling and shifting. Wavelet transforms, decimated and undecimated, are applied to each event. Noise reduction on the set of coefficients of the transformed events is applied using either wavelet denoising or principal component analysis (PCA) noise reduction methodologies. The method does not require any manual selection of coefficients. Nonstationary multievent synthetic signals are employed to demonstrate the performance of the method using normalized mean square error against classicalwavelet andPCAbased algorithms. The new method shows a significant improvement in low SNRs (typically <0 dB). On the experimental side, evoked potentials in a visual oddball paradigm are used. The reduced-noise visual oddball event-related potentials reveal gradual changes in morphology from trial to trial (especially for N1-P2 and N2-P3 waves at Fz), which can be hypothetically linked to attention or decision processes. The new noise reduction method is, thus, shown to be particularly suited for recovering single-event features in nonstationary low SNR multievent contexts.
Peer Reviewed Yes
Published Yes
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Copyright Statement Copyright 2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
Volume 55
Issue Number 7
Page from 1809
Page to 1821
ISSN 0018-9294
Date Accessioned 2009-03-11
Language en_AU
Research Centre Behavioural Basis of Health; Menzies Health Institute Qld
Faculty Griffith Health Faculty
Subject Biological Psychology (Neuropsychology, Psychopharmacology, Physiological Psychology); Signal Processing
Publication Type Journal Articles (Refereed Article)
Publication Type Code c1

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