A Preliminary Usability Assessment of a 3D Printable Orthosis Design System

Abstract. The standard treatment for bones fractures entails the use of a tailor-made plaster cast which has several disadvantages: its weight generally causes discomfort, it cannot be taken off without breaking it, it can cause skin rashes and prevents ventilation of the treated area. Therefore, the application of traditional casts to orthopaedics patients do not represent, to date, the best option. To over-come the above-mentioned drawbacks, many strategies based on reverse engi-neering and additive manufacturing techniques have been proposed and proved to be a valid alternative for producing custom orthoses. Encouraged by the afore-mentioned results, the authors have developed a low-cost system (called Oplà), specifically dedicated to the hand-wrist-arm district of paediatric patients and ca-pable of creating a 3D CAD model of the orthosis ready to be printed by using additive manufacturing techniques. Such a system comprises a 3D scanner, a control software and a semi-automatic CAD procedure to easily model the ortho-paedic device on each patient, without the need of CAD modelling professionals. To evaluate if Oplà can be effectively used by the medical staff to design patient specific 3D printable orthoses in the clinical practice, a preliminary usability as-sessment has been performed. Five professional nurses from the Meyer Chil-dren’s Hospital of Florence (Italy) have been selected and trained in the use of the system. Subsequently, each of them has been asked to perform the whole process for the same patient. Effectiveness, efficiency and satisfaction have been meas-ured in accordance to ISO 9241-11. Results proved that the Oplà system is char-acterized by a good usability allowing the user to easily and intuitively perform all the tasks in a reasonable time.