Effects of anisotropy in a physical torso phantom on source reconstructions from a current dipole

Abstract

In this study, we investigated experimentally the influence of anisotropic compartments on source reconstruction using phantom measurements with an artificial current dipole as signal source. The anisotropic compartment was built from single skeins with a nine times higher conductivity than the surrounding solution. We placed the dipole at the lower borders of the anisotropic bulk and measured the magnetic field and the electric potential for each dipole location. The current dipole was rotated in relation to the anisotropic skeins and potentials and fields were recorded for different angles between anisotropic skeins and current dipole. We found that the estimated dipole orientations are strongly influenced by the anisotropy, while the reconstructed position of the dipole is not significantly influenced. We conclude that for bioelectric and biomagnetic source reconstruction, it is necessary to take into account anisotropic structures in the volume conductor if dipole orientations are of interest.