1 January 2005 Eigenvector-based spatial filtering for reduction of physiological interference in diffuse optical imaging
Author Affiliations +
J. of Biomedical Optics, 10(1), 011014 (2005). doi:10.1117/1.1852552
Abstract
Diffuse optical imaging is an effective technique for noninvasive functional brain imaging. However, the measurements respond to systemic hemodynamic fluctuations caused by the cardiac cycle, respiration, and blood pressure, which may obscure or overwhelm the desired stimulus-evoked response. Previous work on this problem employed temporal filtering, estimation of systemic effects from background pixels, or modeling of interference signals with predefined basis functions, with some success. However, weak signals are still lost in the interference, and other complementary methods are desirable. We use the spatial behavior of measured baseline signals to identify the interference subspaces. We then project signals components in this subspace out of the stimulation data. In doing so, we assume that systemic interference components will be more global spatially, with higher energy, than the stimulus-evoked signals of interest. Thus, the eigenvectors corresponding to the largest eigenvalues of an appropriate correlation matrix form the basis for an interference subspace. By projecting the data onto the orthogonal nullspace of these eigenvectors, we can obtain more localized response, as reflected in improved contrast-to-noise ratio and correlation coefficient maps.
Yiheng Zhang, Dana H. Brooks, Maria Angela Franceschini, David A. Boas, "Eigenvector-based spatial filtering for reduction of physiological interference in diffuse optical imaging," Journal of Biomedical Optics 10(1), 011014 (1 January 2005). http://dx.doi.org/10.1117/1.1852552
JOURNAL ARTICLE
11 PAGES


SHARE
KEYWORDS
Hemodynamics

Spatial filters

Diffuse optical imaging

Heart

Sensors

Blood pressure

Signal to noise ratio

RELATED CONTENT

Photoresponsive behavior of azobenzene hybrid materials
Proceedings of SPIE (August 26 2015)
Feasibility study of a stratospheric-airship observatory
Proceedings of SPIE (March 03 2003)
The Schmidt-Czerny-Turner spectrograph
Proceedings of SPIE (September 05 2014)

Back to Top