Monolithic Multi-Scale Modeling of MR-Induced Pacemaker Lead Heating

Modeling of MR-induced pacemaker lead heating is complicated by, among other things, the multi-scale characteristics of the problem. In this paper, the method of moments is used to model a wide range of length scales of the problem simultaneously including the helix-shaped conducting wires present in the pacemaker lead. A cross-section area conserving meshing scheme for helices is proposed and evaluated. For a relative error of 1%, the meshing scheme reduces the number of thin wire segments needed to model a helix with a factor of roughly 3 to 6, as compared to the conventional approach. In addition, we study the relationship between the maximum induced current on the lead and the number of turns of the helices.