J. Harrison, WJH Engineering Consultants, LLC, Chattanooga, TN
Keywords: Nitinol, superelastic ternary alloy, medical implant, finite element analysis, FEA, stent, self-expanding stent, spinal implant, dynamic spinal rods, fatigue calculations
Abstract:
This study examines the design variables associated with superelastic medical implants, and looks at design trade-offs within those variables. Specifically, a new Nitinol ternary alloy that has been developed and provides extensive increases in plateau stresses adds a larger range to that previously limited design variable. Through design optimization and Finite Element Analyses (FEA), this study shows the benefits that can be obtained by having larger ranges of stress-strain hysteresis. An additional result from this study is how FEA can be utilized to develop optimal products by not only modifying and optimizing the implant shape and dimensions, but also optimizing material choices.
