An Investigation of Trunk Fixity for Wearing Medical Purpose Customized 3D Printing Back Braces by Finite Element Analysis

Abstract

This study aims at the finite element static analysis of 3D printing customized back brace for medical purposes The geometric model was created based on the profile of the trunk to ensure the surface of the brace fits the profile of the trunk The contact model was also considered between the brace and the trunk composed of spine ribs hips and soft tissues The material used in the simulation is PLA (Poly Lactic Acid) The comfortability wearing a back brace can be quantified by the pressure between the skin and the brace In this study the finite element model is used to simulate the pressures of the skin wearing the brace for seven trunk positions including standing flexion extension left rotation right rotation left bending and right bending Pressure injury may occur for high pressures on the skin We also calculated the displacements of the spine which are used to evaluate the fixity to the trunk provided by the brace In the simulation the geometric parameters such as thickness and holes in the brace were considered to evaluate their effects on pressures and fixity As a comparison the finite element models of commercial back braces were also established The simulation results showed that the wear of the customized brace can reduce the pressure on the skin by 11% to 58% depending on which trunk positions are considered The displacements of the spine the simulations also revealed that the customized brace provides a maximum fixity increase of 8% higher than the commercial brace We also found that the thickness and holes in the customized brace have little effects on both the pressure and fixity The simulation results showed the large degree of freedom in geometric designs without decreasing the comfortability and fixity of the customized brace

Date of Award	2020
Original language	English
Supervisor	Chung-De Chen (Supervisor)