Accuracy of Photogrammetric Models for 3D printed Wrist-hand Orthoses

Abstract

Today, 3D printed wrist-hand orthoses can be used to immobilize the arms instead of plaster or fiberglass casts. Typically, 3D arm models for modelling wrist-hand orthoses can be created using a 3D scanning system. Our previous study shows that smartphone cameras and photogrammetry techniques can be used instead of professional 3D scanning systems, but the accuracy of the photogrammetric models has not yet been fully investigated. This paper presents the results of accuracy verification of arm models reconstructed from 2D images captured with a smartphone camera. The forearm and wrist-hand parts of a photogrammetric model were subjected to a virtual inspection by comparing them with the corresponding parts of an arm model created with a 3D scanner. In addition, a physical verification was carried out by assessing the contact between the arm of interest and an actual 3D printed wrist-hand orthosis that was created with reference to the photogrammetric model. The test results show that the photogrammetric models achieve the necessary accuracy to serve as reference models for the construction of 3D printed wrist-hand orthoses.