Analysis of relative errors and bounds in localization of dipoles in various ellipsoidal brain models in Encephalography

Electroencephalography (EEG) measures potential differences on part of the surface of the head. These measurements are directly connected with activated regions within the brain, modeled as dipoles, and are accurately interpreted if originating from a average ellipsoidal conductor with semi-axes 5.5, 6.5 and 8.5 × 10^-2 m. However, the volume of modern human brains varies significantly depending on sex and age. These variations in volume could introduce a source of error affecting the location of the dipole if not incorporated in existing models. In what follows, an error estimation is established for EEG readings in the case where the average ellipsoidal brain is replaced by an ellipsoid with different volume.