Concept and Design of a 3D Printed Support to Assist Hand Scanning for the Realization of Customized Orthosis

Abstract

In the rehabilitation field, the use of additive manufacturing techniques to realize customized orthoses is increasingly widespread. Obtaining a 3D model for the 3D printing phase can be done following different methodologies. We consider the creation of personalized upper limb orthoses, also including fingers, starting from the acquisition of the hand geometry through accurate 3D scanning. However, hand scanning procedure presents differences between healthy subjects and patients affected by pathologies that compromise upper limb functionality. In this work, we present the concept and design of a 3D printed support to assist hand scanning of such patients. The device, realized with FDM additive manufacturing techniques in ABS material, allows palmar acquisitions, and its design and test are motivated by the following needs: (1) immobilizing the hand of patients during the palmar scanning to reduce involuntary movements affecting the scanning quality and (2) keeping hands open and in a correct position, especially to contrast the high degree of hypertonicity of spastic subjects. The resulting device can be used indifferently for the right and the left hand; it is provided in four-dimensional sizes and may be also suitable as a palmar support for the acquisition of the dorsal side of the hand.

Development of modular wrist, hand and finger orthesis by additive manufacturing

“…This technique reduces inaccuracies and noise caused by movements during acquisition (Paterson et al, 2010). Baronio et al, (2017) proposed the use of a support to enable direct scanning of the hand and wrist of people with spasticity, this being a future possibility for the making of this model of orthosis.…”

Experimental Studies on 3D Printing of Automatically Designed Customized Wrist-Hand Orthoses

“…This is usually accomplished by immobilizing and protecting the area around a joint from deformations and physical damage. The orthoses may also be used for enforcement of a specific position and mutual orientation of various body parts [ 21 ]. They can be universal, relatively inexpensive orthoses or customized (much better in terms of healing function and comfort) products made for a specific patient based on their anatomic measurement [ 22 ].…”

Accuracy and Repeatability of Limb Scans Obtained on the Semi-Automatic Measuring Station

“…In [18], the authors presented the concept and design of the device supporting hand scanning for the purpose of creating a personalized orthosis for this part of the human upper limb. Previously, when scanning patients with spasticity of the hand, it was necessary to have an additional person who would correct the abnormal, excessive tension of the patient's muscles (muscle hypertonicity) with their own hands during the scan.…”