This research achieved its purposes of producing a 3D hand parametric hand model in a functional position, using the 3D hand parametric model as a template to generate an individualized approximate 3D hand model, constructing a 3D printed short thumb orthosis with a seamless structural design and ductile materials based on the individualized approximate 3D hand model, and reporting a case study on the usability. In experiment one, 3D hand parametric models were generated using anthropometric data collected with a scanning device from 120 Taiwanese adults. Experiment two examined the feasibility of constructing 3D-printed orthoses from the 3D hand parametric models through a case report on one client. The 19 values of the parameters measured from the client were imported into the 3D hand parametric models. An individual 3D hand mesh model approximating the client's hand was synthesized. The orthosis was precisely sketched and then printed. In usability testing, scores on the Quebec User Evaluation of Satisfaction with Assistive Technology were mostly high. The orthosis provided greater flexibility of hand movement and stronger support than the traditional, manually-formed orthosis. The results indicated the feasibility of using a hand parametric model to optimize the reverse engineering of a short thumb orthosis.
Keywords: 3D printing; customized design; kriging; orthosis; parametric models.