Fast production of customized three-dimensional-printed hand splints

Abstract

Purpose This paper aims to propose a new solution for producing customized three-dimensional (3D)-printed flat-shaped splints, which are then thermoformed to fit the patient’s hand. The splint design process is automated and is available to clinicians through an online application. Design/methodology/approach Patient anthropometric data measured by clinicians are associated with variables of parametric 3D splint models. Once these variables are input by clinicians in the online app, customized stereo lithography (STL) files for both splint and half mold, in the case of the bi-material splint, are automatically generated and become available for download. Bi-materials splints are produced by a hybrid manufacturing process involving 3D printing and overmolding. Findings This approach eliminates the need for 3D CAD-proficient clinicians, allows fast generation of customized splints, generates two-dimensional (2D) drawings of splints for verifying shape and dimensions before 3D printing and generates the STL files. Automation reduces splint design time and cost, while manufacturing time is diminished by 3D printing the splint in a flat position. Practical implications The app could be used in clinical practice. It meets the demands of mass customization using 3D printing in a field where individualization is mandatory. The solution is scalable – it can be extended to other splint designs or to other limbs. 3D-printed tailored splints can offer improved wearing comfort and aesthetic appearance, while maintaining hand immobilization, allowing visually controlled follow-up for edema and rapidly observing the need for revision if necessary. Originality/value An online application was developed for uploading patient measurements and downloading 2D drawings and STL files of customized splints. Different models of splints can be designed and included in the database as alternative variants. A method for producing bi-materials flat splints combining soft and rigid polymers represents another novelty of the research.

Embedding Ultra-High-Molecular-Weight Polyethylene Fibers in 3D-Printed Polylactic Acid (PLA) Parts

“…PLA is cheap to manufacture and procure [15], is biodegradable, and has little-to-no toxicity in its solid form, making it biocompatible [16]. Thus, its applications include biocompatible screws for medical implantation [17], wound dressings using PLA-antioxidant blends [18], and hand splints for emergency splinting [19].…”

Personalized Mass Production by Hybridization of Additive Manufacturing and Injection Molding

“…The areas of application in which a combination of AM and injection molding is economically feasible are most likely to be in medium-scale production. According to [ 12 ], the break-even point of using AM (fused filament fabrication, FFF) and injection molding of Acrylonitrile Butadiene Styrene (ABS) is several hundred units, while for selective laser sintering (SLS) of nylon and injection molding, it is approximately 1000 units. This suggests that the number of products for which the combination of AM and injection molding can be economically feasible ranges from several hundred to several thousand units.…”

“…The literature analysis proves that the combination of AM and injection molding is mostly recommended for medium-volume production with the high necessity of personalization. Laptoiu et al [ 12 ] proposed combining AM and injection molding to produce customized bi-material hand splints. The splint’s rigid part was 3D-printed from polylactic acid, while the soft part was injection molded from fast-curing silicon.…”

Maximizing design potential: investigating the effects of utilizing opportunistic and restrictive design for additive manufacturing in rapid response solutions

“…Additive manufacturing (AM) processes, on account of their layer-bylayer digital material processing, enable designers to rapidly prototype, test and build solutions (Campbell et al, 2012). AM's capability to facilitate rapid response, along with other capabilities such as (1) mass customization (Popescu et al, 2020), (2) part consolidation (Schmelzle et al, 2015) and built assemblies (Patterson et al, 2018), (3) multi-material design (Ribeiro et al, 2019), ( 4) geometric complexity (Rosen, 2007) and ( 5) functional embedding (Kataria and Rosen, 2001;Lopes et al, 2012), have been leveraged to generate innovative solutions for the COVID-19 pandemic (Larrañeta et al, 2020). For example, Pearce, (2020) reviews the various open-source solutions developed for the shortage of ventilator replacement parts and highlights the role of AM in meeting this shortage.…”