Magnetocardiographic computed tomography-a model study on minimum-norm current dipole estimation

A model study on estimating current dipole structures is presented using a computer model of the entire human heart embedded in a homogeneous boundary element (BE) torso model. A surface in the middle of atrial and ventricular myocardium and septum is assumed as reconstruction space. The observation space consists of two perpendicular planes each of them containing 37 observation points on the frontal and left lateral side closely above the human torso. An iterative algorithm in connection with Tikhonov´s method is used in order to calculate pseudo current dipole distributions from simulated MCG data. The regularization parameter λ which balances the two cost functions minimum pseudo current dipole norm and minimal residual norm is determined by the L-curve method or by the generalized-cross-validation method. The effect of the lungs and the blood mass on the forward and inverse solution is neglected