Title :
Linearly constrained minimum variance beamformers, synthetic aperture magnetometry, and MUSIC in MEG applications
Author :
Vrba, J. ; Robinson, S.E.
Author_Institution :
CTF Syst. Inc., Port Coquitlam, BC, Canada
fDate :
Oct. 29 2000-Nov. 1 2000
Abstract :
MUSIC and minimum variance beamformers operated without specific determination of the source orientation (LCMV) or including the orientation (SAM) are methods for discriminating among uncorrelated MEG sources by point-by-point search through the brain volume. Both beamformer types give similar dipole positions, however SAM exhibits better spatial resolution than the LCMV. For spontaneous brain activity when averaging is not possible and in the presence of multiple sources, SAM performs well, while MUSIC is sensitive to the subspace partitioning, and no clear indication about the correct partitioning can be obtained from the eigenspectra.
Keywords :
covariance matrices; inverse problems; magnetoencephalography; medical signal processing; signal classification; signal resolution; MUSIC; covariance matrix; dipole positions; eigenspectra; linearly constrained minimum variance beamformers; multiple signal classification; multiple sources; spatial resolution; spontaneous brain activity; subspace partitioning; synthetic aperture magnetometry; uncorrelated MEG sources; Analytical models; Brain modeling; Covariance matrix; Epilepsy; Imaging phantoms; Multiple signal classification; Noise measurement; Power measurement; Signal to noise ratio; Spatial resolution;
Conference_Titel :
Signals, Systems and Computers, 2000. Conference Record of the Thirty-Fourth Asilomar Conference on
Conference_Location :
Pacific Grove, CA, USA
Print_ISBN :
0-7803-6514-3
DOI :
10.1109/ACSSC.2000.910969