Lead-Specific Optimization of Transfer Function Validation Pathways for Magnetic Resonance RF Safety Evaluation

This article presents a novel lead-specific validation method for magnetic resonance radiofrequency safety evaluations on active implantable medical devices (AIMDs). The proposed method designs a set of optimized validation pathways for the specific AIMD lead which achieve 1) high temperature rise or high induced voltages during the validation measurements with 2) minimally correlated electric fields along the pathways inside a electric field generating phantom box. The novel strategy 1) calculates the heating, or the induced voltage, for 603 preselected pathways and ranks these pathways based on temperature rise or voltage values and 2) performs matrix operations on these pathways to select pathways with minimally correlated tangential electric fields to each other. Two commercially available AIMDs were used to demonstrate the effectiveness of this novel strategy. Consequently, the strategy potentially provides a better transfer function validation for AIMD leads in terms of accuracy and completion.