A Study on Applicability of Using Ferromagnetic Materials to Reduce RF-Induced Heating in External Fixation Systems

Patients with external fixation devices are usually restrained from magnetic resonance imaging (MRI) for the potential hazards due to the accumulation of the RF-induced heating in tissues around the device tips. This paper presents a trailblazing approach to diminish the RF-induced heating in human tissues by adding choke components made of magnetic materials to cut off the energy flowing to human tissues. A circuit model is also developed to describe the mechanism of the method. A typical unilateral frame with single rod construction for tibial fixture is studied as an example. Numerical simulations and experimental measurements are further conducted to verify the approach.