Moving equivalent multipoles derived from the body surface potential map by solving the inverse problem

The aim of this study is to determine instantaneous 3-D locations and moments of moving equivalent multipoles (EM) corresponding to the principal components (PC) obtained from body surface potential map (BSPM) of the CINC/Physionet Challenge 2007 database. Moving EM (three dipoles and one quadrupole) were determined for the successive time windows of 10 ms in steps of 5 ms using multipole models in an unbounded and bounded spherical homogenous conductor. EM parameters were obtained in two steps: in the forward and inverse problem formulation, necessary for the reconstruction of the original BSPM signals. The reconstruction errors in the region of the QRS complex were 1.0% for the first 3 biggest PC, and 6.2% and 5.7% for three dipoles and one quadrupole for the bounded and unbounded EM model, respectively. The corresponding RMS errors were 3.8, 21.5 and 19.8 μV.