MEG/EEG numerical error bounds for a dipole source with a realistic head model

Measures of performance for magnetoencephalography (MEG), electroencephalography (EEG), and the combined MEG/EEG modality are needed in order to compare, improve, and to optimize existing systems and their configuration. We numerically compute bounds on the mean-squared errors when estimating a current dipole's source parameters for a three layered head model using measurements of EEG, MEG and their combination. The electric potentials and magnetic field components are related to the source through integral equations obtained via the boundary element method (BEM). Discretization is achieved with a weighted residuals technique, producing a center of gravity method. The bounds obtained assume knowledge of the layer's conductivities and an accurate representation of the interface surfaces, as obtained from MR or CT imaging.