Low cost digital fabrication approach for thumb orthoses

[EN] Purpose - The purpose of this paper is to describe a novel design workflow for the digital fabrication of custom- made orthoses (CMIO). It is intended to provide an easier process for clinical practitioners and orthotic technicians alike. It further functions to reduce the dependency of the operators' abilities and skills. Design/methodology/approach - The technical assessment covers low-cost three-dimensional (3D) scanning, free computer-aided design (CAD) software, and desktop 3D printing and acetone vapour finishing. To analyse its viability, a cost comparison was carried out between the proposed workflow and the traditional CMIO manufacture method. Findings - The results show that the proposed workflow is a technically feasible and cost-effective solution to improve upon the traditional process of design and manufacture of custom- made static trapeziometacarpal (TMC) orthoses. Further studies are needed for ensuring a clinically feasible approach and for estimating the efficacy of the method for the recovery process in patients. Social implications - The feasibility of the process increases the impact of the study, as the great accessibility to this type of 3D printers makes the digital fabrication method easier to be adopted by operators. Originality/value - Although some research has been conducted on digital fabrication of CMIO, few studies have investigated the use of desktop 3D printing in any systematic way. This study provides a first step in the exploration of a new design workflow using low-cost digital fabrication tools combined with non-manual finishing.Fernandez-Vicente, M.; Escario Chust, A.; Conejero Rodilla, A. (2017). Low cost digital fabrication approach for thumb orthoses. Rapid Prototyping Journal. 23(6):1020-1031. doi:10.1108/RPJ-12-2015-0187S1020103123

The Nurosleeve, a User-Centered 3D Printed Hybrid Orthosis for Individuals With Upper Extremity Impairment

BACKGROUND: Active upper extremity (UE) assistive devices have the potential to restore independent functional movement in individuals with UE impairment due to neuromuscular diseases or injury-induced chronic weakness. Academically fabricated UE assistive devices are not usually optimized for activities of daily living (ADLs), whereas commercially available alternatives tend to lack flexibility in control and activation methods. Both options are typically difficult to don and doff and may be uncomfortable for extensive daily use due to their lack of personalization. To overcome these limitations, we have designed, developed, and clinically evaluated the NuroSleeve, an innovative user-centered UE hybrid orthosis. METHODS: This study introduces the design, implementation, and clinical evaluation of the NuroSleeve, a user-centered hybrid device that incorporates a lightweight, easy to don and doff 3D-printed motorized UE orthosis and a functional electrical stimulation (FES) component. Our primary goals are to develop a customized hybrid device that individuals with UE neuromuscular impairment can use to perform ADLs and to evaluate the benefits of incorporating the device into occupational therapy sessions. The trial is designed as a prospective, open-label, single-cohort feasibility study of eight-week sessions combined with at-home use of the device and implements an iterative device design process where feedback from participants and therapists informs design improvement cycles. RESULTS: All participants learned how to independently don, doff, and use the NuroSleeve in ADLs, both in clinical therapy and in their home environments. All participants showed improvements in their Canadian Occupational Performance Measure (COPM), which was the primary clinical trial outcome measure. Furthermore, participants and therapists provided valuable feedback to guide further development. CONCLUSIONS: Our results from non-clinical testing and clinical evaluation demonstrate that the NuroSleeve has met feasibility and safety goals and effectively improved independent voluntary function during ADLs. The study\u27s encouraging preliminary findings indicate that the NuroSleeve has met its technical and clinical objectives while improving upon the limitations of the existing UE orthoses owing to its personalized and flexible approach to hardware and firmware design. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04798378, https://clinicaltrials.gov/ct2/show/NCT04798378 , date of registration: March 15, 2021

Analysis to Support Design for Additive Manufacturing with Desktop 3D Printing

[ES] En los últimos años, la fabricación aditiva a través de la extrusión de materiales ha experimentado un desarrollo y adopción acelerados gracias a la amplia disponibilidad de máquinas y materiales de bajo costo. El tamaño de estas máquinas se ha reducido del tamaño del taller al tamaño del escritorio, lo que permite su uso en configuraciones de oficina o en el hogar. Este cambio ha permitido la adopción de la tecnología por la gama más amplia de usuarios que nunca, con o sin experiencia en diseño de ingeniería. Este nuevo paradigma ha creado el desafío de cómo habilitar que estos nuevos usuarios aprovechen las capacidades proporcionadas por esta tecnología. Esta tecnología permite la creación de geometrías complejas y productos personalizados con un coste inferior a los procesos de fabricación convencionales. Además, la gran cantidad de usuarios dispuestos a compartir sus diseños permite encontrar soluciones de diseño desde otros diseñadores. Sin embargo, la amplia gama de configuraciones de máquina, parámetros y materiales requiere brindar soporte para obtener resultados exitosos para cualquier combinación. Esta tesis aborda este desafío identificando las características de diseño y fabricación a considerar e investigando las consideraciones mecánicas y de pos procesamiento. Se propone y evalúa un nuevo marco de diseño que permite a los nuevos usuarios aprovechar las capacidades y considerar las limitaciones. Esta investigación encuentra que es posible crear un conjunto de herramientas de diseño que permita a los usuarios no capacitados diseñar productos utilizando la complejidad habilitada por la tecnología al tiempo que garantiza la funcionalidad y la capacidad de fabricación del producto.[CA] En els últims anys, la fabricació additiva a través de l'extrusió de materials ha experimentat un desenvolupament i adopció accelerats gràcies a l'àmplia disponibilitat de màquines i materials de baix cost. La grandària d'aquestes màquines s'ha reduït de la grandària del taller a la grandària de l'escriptori, la qual cosa permet el seu ús en configuracions d'oficina o en a casa. Aquest canvi ha permés l'adopció de la tecnologia per la gamma més àmplia d'usuaris que mai, amb o sense experiència en disseny o enginyeria. Aquest nou paradigma ha creat el desafiament de com habilitar que aquests nous usuaris aprofiten les capacitats proporcionades per aquesta tecnologia. Aquesta tecnologia permet la creació de geometries complexes i productes personalitzats amb un cost inferior als processos de fabricació convencionals. A més, la gran quantitat d'usuaris disposats a compartir els seus dissenys permet trobar solucions de disseny des d'altres dissenyadors. No obstant això, l'àmplia gamma de configuracions de màquina, paràmetres i materials requereix brindar suport per a obtindre resultats reeixits per a qualsevol combinació. Aquesta tesi aborda aquest desafiament identificant les característiques de disseny i fabricació a considerar i investigant les consideracions mecàniques i de post processament. Es proposa i avalua un nou marc de disseny que permet als nous usuaris aprofitar les capacitats i considerar les limitacions. Aquesta investigació troba que és possible crear un conjunt d'eines de disseny que permeta als usuaris no capacitats dissenyar productes utilitzant la complexitat habilitada per la tecnologia al mateix temps que garanteix la funcionalitat i la capacitat de fabricació del producte.[EN] In recent years, additive manufacturing through material extrusion has experienced accelerated development and adoption thanks to the wide availability of low-cost machines and materials. The size of these machines has been reduced from shop floor to desktop size, enabling their usage in office setups or at home. This change has allowed the adoption of the technology by the broadest range of users than ever, with or without an engineering design background. This new paradigm has created the challenge of how to enable these novel users to leverage the capabilities provided by this technology. This technology allows the creation of complex geometry and customised products with a cost lower than conventional manufacturing processes. Furthermore, the large number of users willing to share their designs allows finding design solutions from other designers. However, the wide range of machine configurations, parameters and materials requires providing support to obtain successful results under any combination. This thesis addresses this challenge by identifying the design and manufacturing characteristics to be considered and investigating the mechanical and post-processing considerations. A new design framework that enables new users to leverage the capabilities and consider the limitations is proposed and evaluated. This research finds that it is possible to create a design toolkit that enables untrained users to design products using the complexity enabled by the technology whilst ensuring the product's functionality and manufacturability.Fernández Vicente, M. (2022). Analysis to Support Design for Additive Manufacturing with Desktop 3D Printing [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/185344TESI

Design and Evaluation of Grasp Assistive Devices in an Industrial Environment

Carpal tunnel syndrome and tendonitis are two common upper extremity cumulative trauma disorders related to repetitive and forceful activities in the workplace. The objective of this research was to reduce the hand force during an activity, as reducing task repetition would negatively affect productivity. Two devices were developed to achieve this objective: a soft pneumatic grasp assist device to augment grasp strength, and a novel grip training device to visually alert the user when more force than necessary is used. Device effectiveness was quantified by measuring muscle activity and grip force during an in vivo study of a common industrial activity. Nine associates experienced with power tools employed by an automobile manufacturer installed 18 fasteners using a pistol grip DC tool under three conditions: a typical manner (no device or prompting), with the grasp assist, and with the grip training device. Surface electromyography (sEMG) was used to measure the activity of four muscles commonly associated with grasping – flexor digitorum superficialis (FDS), flexor carpi ulnaris (FCU), extensor digitorum communis (EDC), and flexor carpi radialis (FCR). Results showed that both the grasp assist and grip trainer significantly reduced the mean, combined, normalized muscle activity compared to the typical condition by 18% and 23% respectively (p<0.05). Muscle activation results were contextualized using the revised strain index (RSI), a clinical tool to evaluate the safety of an activity by considering activity specific ergonomic factors. The grasp assist and grip trainer both yielded a significantly lower mean RSI value than the typical condition by 13% and 17% respectively (p<0.05). Grip force was measured using a flexible pressure transducer affixed to the pistol-grip handle of the DC tool. Again, the grasp assist and grip trainer yielded significantly lower values than the typical trial by 47% and 36% respectively (p<0.001). Between devices, the grasp assist yielded a significantly lower grip force the grip trainer (p<0.001); however, the mean muscle activation was not significantly different, which suggests that the four muscles measured in this study do not completely capture grip force. A large variation in grip force was measured for all three conditions with a weak, positive correlation between power tool experience and force applied. Knowledge of the voluntary variation in grip force can be used to educate workers on minimizing the force exerted during an activity

Advances on Mechanics, Design Engineering and Manufacturing III

This open access book gathers contributions presented at the International Joint Conference on Mechanics, Design Engineering and Advanced Manufacturing (JCM 2020), held as a web conference on June 2–4, 2020. It reports on cutting-edge topics in product design and manufacturing, such as industrial methods for integrated product and process design; innovative design; and computer-aided design. Further topics covered include virtual simulation and reverse engineering; additive manufacturing; product manufacturing; engineering methods in medicine and education; representation techniques; and nautical, aeronautics and aerospace design and modeling. The book is organized into four main parts, reflecting the focus and primary themes of the conference. The contributions presented here not only provide researchers, engineers and experts in a range of industrial engineering subfields with extensive information to support their daily work; they are also intended to stimulate new research directions, advanced applications of the methods discussed and future interdisciplinary collaborations

Advances on Mechanics, Design Engineering and Manufacturing III

This open access book gathers contributions presented at the International Joint Conference on Mechanics, Design Engineering and Advanced Manufacturing (JCM 2020), held as a web conference on June 2–4, 2020. It reports on cutting-edge topics in product design and manufacturing, such as industrial methods for integrated product and process design; innovative design; and computer-aided design. Further topics covered include virtual simulation and reverse engineering; additive manufacturing; product manufacturing; engineering methods in medicine and education; representation techniques; and nautical, aeronautics and aerospace design and modeling. The book is organized into four main parts, reflecting the focus and primary themes of the conference. The contributions presented here not only provide researchers, engineers and experts in a range of industrial engineering subfields with extensive information to support their daily work; they are also intended to stimulate new research directions, advanced applications of the methods discussed and future interdisciplinary collaborations

Innovative techniques to devise 3D-printed anatomical brain phantoms for morpho-functional medical imaging

Introduction. The Ph.D. thesis addresses the development of innovative techniques to create 3D-printed anatomical brain phantoms, which can be used for quantitative technical assessments on morpho-functional imaging devices, providing simulation accuracy not obtainable with currently available phantoms. 3D printing (3DP) technology is paving the way for advanced anatomical modelling in biomedical applications. Despite the potential already expressed by 3DP in this field, it is still little used for the realization of anthropomorphic phantoms of human organs with complex internal structures. Making an anthropomorphic phantom is very different from making a simple anatomical model and 3DP is still far from being plug-and-print. Hence, the need to develop ad-hoc techniques providing innovative solutions for the realization of anatomical phantoms with unique characteristics, and greater ease-of-use. Aim. The thesis explores the entire workflow (brain MRI images segmentation, 3D modelling and materialization) developed to prototype a new complex anthropomorphic brain phantom, which can simulate three brain compartments simultaneously: grey matter (GM), white matter (WM) and striatum (caudate nucleus and putamen, known to show a high uptake in nuclear medicine studies). The three separate chambers of the phantom will be filled with tissue-appropriate solutions characterized by different concentrations of radioisotope for PET/SPECT, para-/ferro-magnetic metals for MRI, and iodine for CT imaging. Methods. First, to design a 3D model of the brain phantom, it is necessary to segment MRI images and to extract an error-less STL (Standard Tessellation Language) description. Then, it is possible to materialize the prototype and test its functionality. - Image segmentation. Segmentation is one of the most critical steps in modelling. To this end, after demonstrating the proof-of-concept, a multi-parametric segmentation approach based on brain relaxometry was proposed. It includes a pre-processing step to estimate relaxation parameter maps (R1 = longitudinal relaxation rate, R2 = transverse relaxation rate, PD = proton density) from the signal intensities provided by MRI sequences of routine clinical protocols (3D-GrE T1-weighted, FLAIR and fast-T2-weighted sequences with ≤ 3 mm slice thickness). In the past, maps of R1, R2, and PD were obtained from Conventional Spin Echo (CSE) sequences, which are no longer suitable for clinical practice due to long acquisition times. Rehabilitating the multi-parametric segmentation based on relaxometry, the estimation of pseudo-relaxation maps allowed developing an innovative method for the simultaneous automatic segmentation of most of the brain structures (GM, WM, cerebrospinal fluid, thalamus, caudate nucleus, putamen, pallidus, nigra, red nucleus and dentate). This method allows the segmentation of higher resolution brain images for future brain phantom enhancements. - STL extraction. After segmentation, the 3D model of phantom is described in STL format, which represents the shapes through the approximation in manifold mesh (i.e., collection of triangles, which is continuous, without holes and with a positive – not zero – volume). For this purpose, we developed an automatic procedure to extract a single voxelized surface, tracing the anatomical interface between the phantom's compartments directly on the segmented images. Two tubes were designed for each compartment (one for filling and the other to facilitate the escape of air). The procedure automatically checks the continuity of the surface, ensuring that the 3D model could be exported in STL format, without errors, using a common image-to-STL conversion software. Threaded junctions were added to the phantom (for the hermetic closure) using a mesh processing software. The phantom's 3D model resulted correct and ready for 3DP. Prototyping. Finally, the most suitable 3DP technology is identified for the materialization. We investigated the material extrusion technology, named Fused Deposition Modeling (FDM), and the material jetting technology, named PolyJet. FDM resulted the best candidate for our purposes. It allowed materializing the phantom's hollow compartments in a single print, without having to print them in several parts to be reassembled later. FDM soluble internal support structures were completely removable after the materialization, unlike PolyJet supports. A critical aspect, which required a considerable effort to optimize the printing parameters, was the submillimetre thickness of the phantom walls, necessary to avoid distorting the imaging simulation. However, 3D printer manufacturers recommend maintaining a uniform wall thickness of at least 1 mm. The optimization of printing path made it possible to obtain strong, but not completely waterproof walls, approximately 0.5 mm thick. A sophisticated technique, based on the use of a polyvinyl-acetate solution, was developed to waterproof the internal and external phantom walls (necessary requirement for filling). A filling system was also designed to minimize the residual air bubbles, which could result in unwanted hypo-intensity (dark) areas in phantom-based imaging simulation. Discussions and conclusions. The phantom prototype was scanned trough CT and PET/CT to evaluate the realism of the brain simulation. None of the state-of-the-art brain phantoms allow such anatomical rendering of three brain compartments. Some represent only GM and WM, others only the striatum. Moreover, they typically have a poor anatomical yield, showing a reduced depth of the sulci and a not very faithful reproduction of the cerebral convolutions. The ability to simulate the three brain compartments simultaneously with greater accuracy, as well as the possibility of carrying out multimodality studies (PET/CT, PET/MRI), which represent the frontier of diagnostic imaging, give this device cutting-edge prospective characteristics. The effort to further customize 3DP technology for these applications is expected to increase significantly in the coming years

The value of personalised consumer product design facilitated through additive manufacturing technology

This research attempted to discover how Additive Manufacturing (AM) can best be used to increase the value of personalised consumer products and how designers can be assisted in finding an effective way to facilitate value addition within personalisable product designs. AM has become an enabler for end-users to become directly involved in product personalisation through the manipulation of three-dimensional (3D) designs of the product using easy-to-use design toolkits. In this way, end-users are able to fabricate their own personalised designs using various types of AM systems. Personalisation activity can contribute to an increment in the value of a product because it delivers a closer fit to user preferences. The research began with a literature review that covered the areas of product personalisation, additive manufacturing, and consumer value in product design. The literature review revealed that the lack of methods and tools to enable designers to exploit AM has become a fundamental challenge in fully realising the advantages of the technology. Consequently, the question remained as to whether industrial designers are able to identify the design characteristics that can potentially add value to a product, particularly when the product is being personalised by end-users using AM-enabled design tools and systems. A new value taxonomy was developed to capture the relevant value attributes of personalised AM products. The value taxonomy comprised two first-level value types: product value and experiential value. It was further expanded into six second-level value components: functional value, personal-expressive value, sensory value, unique value, co-design value, and hedonic value. The research employed a survey to assess end-users value reflection on personalised features; measuring their willingness to pay (WTP) and their intention to purchase a product with personalised features. Thereafter, an experimental study was performed to measure end-users opinions on the value of 3D-printed personalised products based on the two value types: product value and experiential value. Based on the findings, a formal added value identification method was developed to act as a design aid tool to assist designers in preparing a personalisable product design that embodies value-adding personalisation features within the product. The design method was translated into a beta-test version paper-based design workbook known as the V+APP Design Method: Design Workbook. The design aid tool was validated by expert designers. In conclusion, this research has indicated that the added value identification method shows promise as a practical and effective method in aiding expert designers to identify the potential value-adding personalisation features within personalisable AM products, ensuring they are able to fully exploit the unique characteristics and value-adding design characteristics enabled by AM. Finally, the limitations of the research have been explained and recommendations made for future work in this area