Real Time Ballistocardiogram Artifact Removal in EEG-fMRI Using Dilated Discrete Hermite Transform
Anandi Mahadevan · OhioLink ETD Center (Ohio Library and Information Network) · 2008
Electroencephalogram (EEG) signals, when recorded within the strong magnetic field of an MR scanner, are subject to various artifacts, of which the ballistocardiogram (BCG) is one of the prominent artifacts affecting the quality of the EEG.The BCG is continuously varying with time and its spectrum overlaps with the EEG spectra, making its suppression a signal processing challenge.A novel method for the identification and removal of this artifact using shape basis functions of the new dilated discrete Hermite transform is investigated in this paper.The BCG artifacts are modeled for every heart beat, using these discrete Hermite basis functions, and are subsequently subtracted from the ongoing EEG.Experimental EEG data was recorded inside and outside a 3 Tesla MRI scanner, from a total of 7 subjects under various experimental conditions.Quantitative assessment Dr. Dale H. Mugler.He has been a constant source of inspiration and pillar of strength throughout the course of this Masters Thesis.His valuable suggestions and advice have helped me greatly in getting this work to a stage of completion.My Committee Members, Dr. Daniel Sheffer and Dr. Stuart Clary have spared their valuable time whenever I needed and provided me immense support to realize the fruition of my efforts.Dr. Sheffer has helped greatly with his timely and insightful suggestions in Bio-Statistics and Dr.Clary has been a great source of help in terms of understanding and implementation of Hermite functions.