Wavelet-Based Estimation of Hemodynamic Response Function

Srikanth, R and Muralishankar, R and Ramakrishnan, AG (2004) Wavelet-Based Estimation of Hemodynamic Response Function. [Book Chapter]

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Abstract

We present a new algorithm to estimate hermodynamic response function (HRF) and drift component in wavelet domain. The HRF is modeled as a gaussian function with unknown parameters. The functional Magnetic resonance Image (fMRI) noise is modeled as a fractional brownian motion (fBm). The HRF parameters are estimated in wavelet domain since wavelet transform with sufficient number of vanishing moments decorrelates a fBm process. Due to this decorrelating property of wavelet transform, the noise covariance matrix in wavelet domain can be assumed to be diagonal whose entries are estimated using sample variance estimators at each scale. We study the influence of sampling time and shape assumption on the estimation performance. Results are presented by adding synthetic HRFs on null fMRI data.

Item Type:	Book Chapter
Series.:	Lecture Notes in Computer Science
Publisher:	Springer V.B.
Additional Information:	Copyright of this article belongs to Springer V.B.
Department/Centre:	Division of Electrical Sciences > Electrical Engineering
Date Deposited:	19 Dec 2008 19:41
Last Modified:	19 Sep 2010 04:56
URI:	http://eprints.iisc.ac.in/id/eprint/17386

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