Research Article A Critical Analysis of a Hand Orthosis Reverse Engineering and 3D Printing Process Gabriele Baronio, 1 Sami Harran, 1 and Alberto Signoroni 2 1 Dipartimento di Ingegneria Meccanica e Industriale, Universit` a degli Studi di Brescia, Via Branze 38, 25123 Brescia, Italy 2 Dipartimento di Ingegneria dell’Informazione, Universit` a degli Studi di Brescia, Via Branze 38, 25123 Brescia, Italy Correspondence should be addressed to Gabriele Baronio; gabriele.baronio@unibs.it Received 29 April 2016; Revised 5 July 2016; Accepted 13 July 2016 Academic Editor: Tadeusz Mikołajczyk Copyright © 2016 Gabriele Baronio et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te possibility to realize highly customized orthoses is receiving boost thanks to the widespread difusion of low-cost 3D printing technologies. However, rapid prototyping (RP) with 3D printers is only the fnal stage of patient personalized orthotics processes. A reverse engineering (RE) process is in fact essential before RP, to digitize the 3D anatomy of interest and to process the obtained surface with suitable modeling sofware, in order to produce the virtual solid model of the orthosis to be printed. In this paper, we focus on the specifc and demanding case of the customized production of hand orthosis. We design and test the essential steps of the entire production process with particular emphasis on the accurate acquisition of the forearm geometry and on the subsequent production of a printable model of the orthosis. Te choice of the various hardware and sofware tools (3D scanner, modeling sofware, and FDM printer) is aimed at the mitigation of the design and production costs while guaranteeing suitable levels of data accuracy, process efciency, and design versatility. Eventually, the proposed method is critically analyzed so that the residual issues and critical aspects are highlighted in order to discuss possible alternative approaches and to derive insightful observations that could guide future research activities. 1. Introduction In the orthopedics and rehabilitation felds the personal- ization of the patient care is increasingly infuenced by the development of new additive manufacturing (AM) technolo- gies and, in particular, by the difusion of 3D printers. As evidenced in Negi et al. [1] and in Hieu et al. [2], various rapid prototyping (RP) techniques are workable in the medical feld. In particular, the use of 3D printers is spreading in the orthotics feld and their difusion is expected to rapidly increase in the near future, given the continuous evolution of available materials and the lowering of the device and production costs of the various AM technologies. If it is true that the use of AM processes allows attaining high level of customization, this requires that a geometric model of the orthosis to be realized (3D printed) has to be generated frst. It is therefore necessary that a reverse engi- neering (RE) process precedes the implementation phase. Te three main phases of an RE/RP of an orthosis by 3D printing technologies can be outlined as follows: (1) Acquisition of the 3D geometry of the interested anatomy using an optical 3D scanner. (2) Processing of the acquired data through dedicated sofware (including CAD 3D modelers). (3) Realization of the orthosis using a 3D printer. While for the third phase suitable (possibly low-cost) hard- ware can be chosen according to specifc needs and among the available and well identifable AM technologies, the frst two phases are instead far from being self-evident. In fact, for the frst phase there are a variety of possible acquisition technolo- gies (i.e., structure form motion and dense stereo imaging, time-of-fight range imaging, laser scanners, and structured- light scanners) and modalities (e.g., static multiview or real- time incremental acquisitions) that can correspond to very Hindawi Publishing Corporation Applied Bionics and Biomechanics Volume 2016, Article ID 8347478, 7 pages http://dx.doi.org/10.1155/2016/8347478