Multiple dipole modeling of spatio-temporal MEG (magnetoencephalogram) data

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6772823

Mosher, J C ^[1]; Lewis, P S ^[2]; Leahy, R ^[3]; Singh, M ^[4]

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1. TRW Defense Systems Group, Redondo Beach, CA (USA). Systems Engineering and Development Div. University of Southern California, Los Angeles, CA (USA). Signal and Image Processing Inst.
2. Los Alamos National Lab., NM (USA)
3. University of Southern California, Los Angeles, CA (USA). Signal and Image Processing Inst.
4. University of Southern Californi

An array of SQUID biomagentometers may be used to measure the spatio-temporal neuromagnetic field produced by the brain in response to a given sensory stimulus. A popular model for the neural activity that produces these fields is a set of current dipoles. We present here a common linear algebraic framework for three common spatio-temporal dipole models: moving and rotating dipoles, rotating dipoles with fixed location, and dipoles with fixed orientation and location. Our intent here is not to argue the merits of one model over another, but rather show how each model may be solved efficiently, and within the same framework as the others. In all cases, we assume that the location, orientation, and magnitude of the dipoles are unknown. We present the parameter estimation problem for these three models in a common framework, and show how, in each case, the problem may be decomposed into the estimation of the dipole locations using nonlinear minimization followed by linear estimation of the associated moment time series. Numerically efficient means of calculating the cost function are presented, and problems of model order selection and missing moments are also investigated. The methods described are demonstrated in a simulated application to a three dipole problem. 21 refs., 2 figs., 1 tab.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6772823
• Report Number(s): LA-UR-90-2157; CONF-9007117-1; ON: DE90013154
• Resource Relation: Conference: SPIE conference on mathematical imaging, San Diego, CA (USA), Jul 1990
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BRAIN
MAGNETIC FIELDS
STIMULATION
BIOT-SAVART LAW
DIPOLES
MAGNETIC DIPOLES
MAGNETOMETERS
MATHEMATICAL MODELS
NEUROLOGY
SPATIAL DISTRIBUTION
THREE-DIMENSIONAL CALCULATIONS
BODY
CENTRAL NERVOUS SYSTEM
DISTRIBUTION
MEASURING INSTRUMENTS
MEDICINE
MULTIPOLES
NERVOUS SYSTEM
ORGANS
551000* - Physiological Systems