Master of Science
Dr. Blaine A. Chronik
Background: The current procedures and guidelines for testing medical devices require that conservative testing be carried-out using the “worst-case” device or device configuration for each interaction (force, torque, heating, et cetera) of importance, and the results of those tests be used to inform regulatory labeling for that device. One of the most difficult elements of carrying out the above procedure is the determination of what represents a “worst-case” device or device configuration. A simulation “pipeline” would enable a systematic procedure for identification of the worst-case device or device configuration for magnetic force from an otherwise impossibly large set of options.
Methods: Using a combination of computational and analytic methods, a comprehensive capacity to simulate and predict the static magnetic field interactions, specifically magnetic force, experienced by any medical device in any MRI-relevant environment is developed. This computational model is validated through comparison to derived analytic solutions and experimental testing performed in accordance to ASTM F2052-15.
Results: Through analytic validation, it is found that the computational model of magnetic force is ideal for use on materials with magnetic susceptibility less than 104 ppm, such as medical implant-grade metals. Experimentally, the computational model of force correctly predicted the force on two steels of magnetic susceptibility <104 ppm within less than 1% difference than the current testing procedure.
Conclusion: The computational model of force is recommended for use in medical device testing applications as a way to identify what represents a “worst-case” device or device configuration.
Parent, Spencer Baird, "Static Magnetic Field Interactions of Medical Devices in The MRI Environment" (2016). Electronic Thesis and Dissertation Repository. 4347.