Dependence of the inverse solution accuracy in magnetocardiography on the boundary-element discretization

Modeling in magnetocardiography is increasingly based on the boundary-element method. We quantify the influence of the boundary-element discretization on the cardiomagnetic forward and inverse problem for different dipole depths and regions of the heart. Simulations using single current dipoles and a high resolution boundary-element model (edge length <10 mm) are used to assess models of various complexity (with and without blood masses) and discretization. It is found that the maximum localization error of about 5 mm occurs if the test dipole is very close to one of the boundaries (lungs). Edge lengths of 20, 15, and 8 mm for the torso, lungs, and ventricles, respectively, are sufficient to reach a localization accuracy of 2 mm.