Three-dimensional printing of components for a dynamic upper extremity orthotic: Prototype development: Topics: Advances in upper limb robotics, other

摘要

For patients with upper extremity (UE) functional deficits due to neuromuscular disorders (e.g. stroke), orthotic designs can employ complex assemblies to facilitate functional recovery and augmentation. Three-dimensional (3D) printing technology presents significant benefits to orthotic design, fabrication, and availability. Using advanced printers and an ever-diversifying selection of printable materials, 3D printing has potential to accommodate the design specifications (e.g. static support, dynamic assistance) of a multi-component assembly. Thus, this technology promises to reduce fabrication overhead, to improve access to orthotics, to minimize orthotic repair/replacement concerns, and to facilitate rapid design modification/turnaround. This latter benefit is a crucial aspect for patients requiring serial adjustments to orthotic fit/function during their rehabilitation course. To support technology development, this research project compares an existing upper extremity orthotic with a modified version. This modified orthotic will rely on 3D printing to fabricate elastic components comparable to the metal springs of the original orthotic. To quantify this comparison, testing will comprise standard engineering measures and a clinical study. Engineering measures will include spring coefficient, tensile strength, and fatigue limit. The clinical study will involve repeat measures experimental design; three patients with upper extremity deficits secondary to stroke will perform a standardized UE functional assessment tool (e.g. Box and Block Test) using the original orthotic or the modified orthotic. Each patient will then switch orthotic and repeat the assessment. Data will be analyzed with intent to prove concept, demonstrate potential, and identify areas of improvement for 3D printing technology. At present, our interdisciplinary team of clinicians and engineers has accomplished the following objectives: (i) selection and trial operation of a 3D printer, (ii) identification of potential printable filaments, and (iii) successful fabrication of standardized test elements to support engineering evaluation. Ensuing efforts will focus toward designing the elastic components with computer aided design (CAD) software and then employing expertise from prior objectives to fabricate a functional prototype to support the clinical study.