Enhancing Skin-Effect Using Surface Roughening and its Potential to Reduce RF Heating from Implant Leads

Sinduja Seshadri and Jonathan Scott

Patients wearing DBS or SCS implants experience RF heating when subjected to an MRI scan that operates at a frequency of 128 MHz. One technique is applying the concept of loss due to skin-effect on an implant lead wire at MRI frequency. A coaxial resonator of 1/4 wavelength with copper conductors was constructed to test the insertion loss using S12 parameter from a VNA. The smooth inner copper rod was compared with rough inner copper rod to determine the difference between the Q-value of the resonator. Roughening the surface does enhance the skin-effect loss but the loss is insufficient to translate it to an implant lead which is inserted in a patient.