Modeling RF-Induced Power Deposition and Temperature Rise of Coaxial Leads with Helical Wires

Area of Science:

• Electromagnetics
• Biomedical Engineering
• Medical Device Technology

Background:

• Radiofrequency (RF) energy is used in various medical procedures.
• Insulated leads are critical components in RF delivery systems.
• Accurate modeling of electromagnetic interactions is essential for device safety and efficacy.

Purpose of the Study:

• To develop and validate a lead electromagnetic model (LEM) for insulated leads.
• To analyze radiofrequency responses, specifically net dissipated electrode power and temperature increase.
• To investigate the performance differences between lead and ring electrodes under RF heating.

Main Methods:

• Modeling of two coax-type insulated leads with helical wires using the lead electromagnetic model (LEM).
• Analysis of radiofrequency responses including net dissipated electrode power and net temperature increase.
• Statistical comparison of model-fitted values against observed data using the quotient of variances (R²).

Main Results:

• The lead electromagnetic model (LEM) successfully simulated RF responses for the insulated leads.
• A significant difference in the goodness-of-fit (R²) was observed between the lead electrode and the ring electrode.
• The R² for the ring electrode was dependent on the duration of RF-induced heating.

Conclusions:

• The LEM provides a viable approach for modeling RF interactions in insulated leads.
• Electrode design (lead vs. ring) influences RF energy deposition and heating patterns.
• Further investigation into the temporal dynamics of RF heating is warranted for ring electrodes.