Design of a padded patient specific wrist cast for 3D printing-thermoforming technique

Abstract

This study proposed two designs of padded patient specific wrist cast as an alternative using the 3D printing thermoforming production technique. These designs were printed as a flat structure with and without hinge joints. The casts were 3D printed with polylactic acid (PLA) filament as the main structure and thermoplastic polyurethane (TPU) as the padding material. The casts were fitted to the subject’s wrist by thermoforming the printed structure. The strength of the proposed structure was analyzed using finite element analysis (FEA) during the design stage to estimate the mechanical properties of the proposed cast such as local displacement under a specific load, stress and safety factor. The thermoforming tests of the proposed designs at various temperatures were conducted experimentally to observe any crack and delamination after thermoforming. The design with hinge joint was selected based on its proper post-thermoforming fit as a functional wrist cast.