DESIGN FOR PEOPLE AFFECTED BY DUCHENNE MUSCULAR DYSTROPHY. Proposal for a new type of night AFO, Ankle Foot Orthosis, based on 3D indirect survey and 3D printing.

Abstract

The aim of this study is to investigate night Ankle Foot Orthoses, commonly prescribed to Duchenne Muscular Dystrophy patients to understand if there are margins to increase their comfort, aesthetic customization and psychological acceptance by the users, but even to improve their manufacturing process and to reduce costs. Duchenne is a rare form of muscular dystrophy affecting 1 on 3.500 male children that, at about 8 to 12 years old progressively become wheelchair bounded and with an expectation of life on the late 20 or 30 years old, since usually cardiac or pulmonary complications occur. Due to muscles’ weakening, Achilles tendon takes over on muscle tissue and starts to thicken and shrink, causing plantar flexion and retractions, while the function of AFOs is for applying a stretching force that can delay equine deformation of the feet. It is scientifically demonstrated that a constant use of night Ankle Foot Orthosis, together with physiotherapy, can extend the independent ambulation by up to two years and delay the occurrence of other complications. The PhD study was conducted from 2012 to 2014 thanks to a partnership between the Department of Architecture of Ferrara University and Parent Project Onlus for Duchenne and Becker. Moreover the thesis was endorsed by the Neuropsychiatric Department specialized in Duchenne of the Policlinico Gemelli in Rome, orthoses manufactures, experts in 3D survey, parametric design, and solid prototyping and, last but not least, by the direct contact with final users and their families. The core of the thesis was organized in three parts. In the first one, after a brief recognition on the disease, a market analysis on all the lower limb orthoses available on Italian, European and North American market was conducted. The elaborated interactive database was essential to understand the state of art, the Italian picture and the most advanced innovations and ongoing experimentations. All these data were a crucial tool in the design process. The second part focused on cultural and methodological approaches in the design of the AFO. After an overview on theories that frame the research, as Customer Centered and User Centered Design, as well as Universal Design, Inclusive Design, Design for All and Design for disabilities, a Quality Function Deployment process was chosen to translate theories into design directives. Relating user needs, technical requirements and comparison with the competitors, the scheme provides the guidelines for the design of a really innovative dorsal night AFO for DMD patients. The results of the research and future perspective are exposed in the third part. The analysis of the handcraft current processes of manufacturing suggested the opportunity of investigating the application of modern technologies aimed at the optimization of the process and the final product. Indirect survey techniques of photo-modelling or laser scanner are used to accurately reproduce the shape of the leg, while the user is sitting on a particular bench designed to acquire the foot in a stretching position and to entertain the child as he was on a rocking horse. The 3D virtual reconstruction of the limb, combined with 15 control points, is elaborated in an algorithm of parametric design to obtain a customized AFO that can be 3D printed with complete freedom of personalization to meet the tastes of the child. The results are highly promising and deserve to be further developed in future experimentations on field.