Application of lead field theory and computerized thorax modeling for the ECG inverse problem

The ECG inverse problem is a widely studied area, and several different approaches have been used to solve it. The present study introduces the reciprocally calculated lead field concept for solving the ECG inverse problem. The lead field approach based. on the reciprocity theorem provides a procedure to calculate the computationally heavy forward problem by a single solution for each ECG lead. In this study, one anatomically detailed 3D FDM model of the human thorax as a volume conductor was employed for forward and inverse estimation of ECG potentials and cardiac sources, respectively. Several equivalent dipole sources were set into the cardiac muscle and the surface potential distributions applying 12, 24, 32, 64, and 120-lead ECG electrode configurations were computed. The inverse problem was solved in order to localize the dipoles based on the information obtained from the simulated ECG recordings and the characteristics of the volume conductor. The dipole localization errors ranged from 2 to 5 mm depending on the number of electrodes. Thus, the lead field method appears to be applicable for the solution of the ECG inverse problem.