Laser Surface Modification Of Medical Grade Alloys For Reduced Heating In A Magnetic Resonance Imaging Environment

Abstract

Nanoscale surface modification of medical grade metallic alloys was conducted using a neodymium-doped yttrium aluminum garnet laser-based dopant diffusion technique. The objective of this approach was to minimize the induction heating by reducing the absorbed radio frequency field. Such an approach is advantageous in that the dopant is diffused into the alloy and is not susceptible to detachment or spallation as would an externally applied coating, and is expected to not deteriorate the mechanical and electrical properties of the base alloy or device. Experiments were conducted using a controlled environment laser system with the ability to control laser properties (i.e., laser power, spot size, and irradiation time) and dopant characteristics (i.e., temperature, concentration, and pressure). The reflective and transmissive properties of both the doped and untreated samples were measured in a radio frequency (63.86 MHz) magnetic field using a system comprising a high power signal generator, a localized magnetic field source and sensor, and a signal analyzer. The results indicate an increase in the reflectivity of the laser-treated samples compared to untreated samples. The effect of reflectivity on the heating of the alloys is investigated through a mathematical model incorporating Maxwell's equations and heat conduction.

Publication Date

12-1-2015

Publication Title

Review of Scientific Instruments

Volume

86

Issue

12

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1063/1.4936970

Socpus ID

84951335379 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84951335379

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