Development of a parametric simulation framework for additively manufactured orthotic components considering patient specific biomechanical requirements

Abstract

The present study describes the development of a simulation-based model for the patient-specific design of functional orthotic components using additively manufactured spring structures. The aim of this study is to propose a methodology that facilitates the customization of functional, spring-like elements to individual biomechanical requirements. The design is executed parametrically, with geometric parameters systematically varied within a full factorial design of experiments. To represent the nonlinear and anisotropic behavior of additively manufactured polypropylene components in numerical simulations, the Three-Network-Model is employed and calibrated for the manufacturing orientations horizontal, diagonal, and vertical. The numerical analysis performed, utilizing the finite element method, facilitates precise prediction of force and moment responses over time under realistic loading conditions. The experimental validation demonstrated a high level of agreement with the simulation results, particularly for diagonally manufactured spring structures. Based on the finite element simulations, a quadratic regression model is developed for algorithmic geometry optimization and implemented in a semi-automated design tool. The utilization of patient-specific biomechanical data facilitates the design of orthotic components that are optimized both functionally and for manufacturing.