Shape modification of the Boston brace using a finite-element method with topology optimization.

Abstract

Using a finite-element (FE) method to reshape the Boston brace, and evaluating the correction effect of the modified Boston brace in terms of Cobb angle. This study aimed to reduce the weight of the Boston brace using a FE method with topology optimization. The Boston brace is widely used to correct an abnormal spinal curve in adolescent idiopathic scoliosis. However, patients wearing the brace usually complain about discomfort caused by its bulkiness. An FE model of a traditional Boston brace was constructed using the software ANSYS 9.0. The loading condition was taken from an X-sensor measuring contact pressures between torso and brace. Topology optimization was conducted to modify the Boston brace. Three patients wearing a traditional brace and then the modified brace were examined in terms of Cobb angle. For the patient with King Type III scoliosis, this modified brace was able to offer the same correction effect as the traditional brace, but the modified brace was lighter by about 12.4%, with the potential to be up to 18% lighter. Based on the traditional Boston brace, this FE model, combined with topology optimization, can effectively estimate redundant material distribution and accordingly custom-design a lighter brace without any loss of its corrective effect.