Modeling and Measurement of Lead Tip Heating in Implanted Wires with Loops

Motivation: Lead tip heating is a safety concern for subjects with implanted devices. Systematic modeling of the effect of loops on heating has not been reported. Goal(s): Theoretically and experimentally study implant lead tip heating caused by radiofrequency power deposition in different looped wire configurations. Approach: Maximum temperature rise was measured on 15 insulated, capped wires with various loop configurations. Results were compared with predictions from two models previously applied to straight wires. Results: For vertically placed wires, increasing the number of loops decreased overall heating. Both models effectively predicted the trends in lead tip temperature rise for all configurations. Impact: A model that can be applied to predict lead tip heating with various lead configurations could potentially inform lead placement strategies and improve safety protocols, i.e., allow greater access to MRI for patients with implants.