Simulations of magnetocardiographic signals using realistic geometry models of the heart and torso

[摘要] Although the first measurement of the cardiac magnetic field wasreported almost half a century ago magnetocardiography (MCG) isnot yet widely used as a clinical diagnostic technique. With thedevelopment of a new generation of magnetoelectric sensors it isbelieved that MCG will become widely accepted in the clinicaldiagnosis. Our goal is to build a computer-based tool for medicaldiagnosis and to use it for the clarification of openelectro-physiological questions. Here we present results frommodelling of the cardiac electrical activity and computation ofthe generated magnetic field. For the simulations we use MRT-basedanatomical models of the human atria and ventricles where theshape of the action potential is determined by ionic currentspassing through the cardiac cell membranes. The monodomainreaction-diffusion equation is chosen for the description of theheart's electrical activity. This equation is solved for thetransmembrane voltage which is in turn used to calculate currentdensities at discrete time instants. In subsequent simulationsthese current densities represent primary sources of magnetostaticfields arising from a volume conduction problem. In thesesimulations the heart is placed in a realistic torso model wherethe lungs are also considered. Both, the volume conduction problemas well as the reaction-diffusion problem are modelled usingFinite-Element techniques.

[学科分类] 电子、光学、磁材料