Electromagnetic Modeling of the Implantable Electrode for Transfer Function Calibration in MRI RF-Induced Heating Assessment

Radiofrequency-induced heating represents a significant and intricate challenge during the combined use of magnetic resonance imaging and active implantable medical devices. The coupling of the transfer function (TF) determination process and radiofrequency (RF) exposure experiment is a perennial problem in the field. In this study, the tip electrode was separated from the lead and numerically modeled for analysis. The current induced at the electrode in the TF measurement scenario was estimated by analyzing the electromagnetic (EM) fields near the electrode. The magnitude of TF was calibrated according to the estimated current source. The tip response under RF exposure is independently predicted with an error of less than 10% using the obtained scaled TF in simulation studies. Near-electrode EM fields analysis introduces a novel perspective in RF-induced heating evaluation study.