Design and development of a novel 3D-printed non-metallic self-locking prosthetic arm for a forequarter amputation

2020 ◽  
pp. 030936462094829 ◽  
Author(s):  
Trevor Binedell ◽  
Eugene Meng ◽  
Karupppasamy Subburaj
Keyword(s):  
Computer Aided Design ◽  
Ease Of Use ◽  
Prosthetic Design ◽  
Forequarter Amputation ◽  
Digital Scanning ◽  
Survey Results ◽  
3D Printed ◽  
And Function ◽  
The Cost ◽  
Aided Design

Background: Upper limb, in particular forequarter amputations, require highly customised devices that are often expensive and underutilised. Objectives: The objective of this study was to design and develop a comfortable 3D-printed cosmetic forequarter prosthetic device, which was lightweight, cool to wear, had an elbow that could lock, matched the appearance of the contralateral arm and was completely free of metal for a specific user’s needs. Study Design: Device design. Technique: An iterative user-centred design approach was used for digitising, designing and developing a functional 3D-printed prosthetic arm for an acquired forequarter amputation, while optimising the fit and function after each prototype. Results: The cost of the final arm was 20% less expensive than a traditionally-made forequarter prostheses in Singapore. The Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST) 2.0 survey was administered, with results indicating that the 3D-printed arm was preferred due to its overall effectiveness, accurate size, ease of use and suspension. However, durability had a lower score, and the weight of the arm was 100 g heavier than the user’s current prosthesis. The technique described resulted in a precise fitting and shaped forequarter prosthesis for the user. Using the user’s feedback in the iterations of the design resulted in improved QUEST survey results indicating the device was effective, easy to use, perceived as lighter and more secure than the user’s traditionally-made device. Conclusion: A fully customised cosmetic forequarter prosthesis was designed and developed using digital scanning, computer-aided design modelling and 3D printing for a specific user. These technologies enable new avenues for highly complex prosthetic design innovations.

CAD Of Anticorrosive Protection Of Steel Structures

2019 ◽  
pp. 18-23
Keyword(s):  
Protective Coating ◽  
Computer Aided Design ◽  
Steel Structures ◽  
Cost Effective ◽  
Operating Conditions ◽  
Computational Tool ◽  
Protection Method ◽  
Cost Effective Method ◽  
The Cost ◽  
Aided Design

The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.

Effect of infill and density pattern on the mechanical behaviour of ABS parts manufactured by FDM using Taguchi and ANOVA approach

2021 ◽  
Vol 111 (2) ◽  
pp. 66-77
Author(s):  
M. Othmani ◽  
K. Zarbane ◽  
A. Chouaf
Keyword(s):  
Tensile Strength ◽  
Computer Aided Design ◽  
Numerical Test ◽  
Acrylonitrile Butadiene Styrene ◽  
Tensile Behaviour ◽  
Element Analysis ◽  
Mechanical Tensile ◽  
Experimental Values ◽  
The Cost ◽  
Aided Design

Purpose: The present work aims to investigate the effect of many infill patterns (rectilinear, line, grid, triangles, cubic, concentric, honeycomb, 3D honeycomb) and the infill density on the mechanical tensile strength of an Acrylonitrile Butadiene Styrene (ABS) test specimen manufactured numerically by FDM. Design/methodology/approach: Computer-Aided Design (CAD) software has been used to model the geometry and the mesostructure of the test specimens in a fully automatic manner from a G-code file by using a script. Then, a Numerical Design of Experiments (NDoE) has been carried out by using Taguchi method and the Analysis of Variance (ANOVA). The tensile behaviour of these numerical test specimens has been studied by the Finite Element Analysis (FEA). Findings: The FEA results showed that a maximal Ultimate Tensile Strength (UTS) was reached by using the ‘concentric’ infill pattern combined with an infill density of 30%. The results also show that the infill pattern and the infill density are significant factors. Research limitations/implications: The low infill densities of 20% and 30% that have already been used in many previous studies, we have also applied it in order to reduce the time of the simulations. Indeed, with high infill density, the simulations take a very excessive time. In an ongoing study, we predicted higher percentages. Practical implications: This study provided an important modelling tool for the design and manufacture of functional parts and helps the FDM practitioners and engineers to manufacture strong and lightweight FDM parts by choosing the optimal process parameters. Originality/value: This study elucidated the effect of various infill patterns on the tensile properties of the test specimens and applied for the first time a NDoE using numerical test specimens created by the mesostructured approach, which considerably minimized the cost of the experiments while obtaining an error of 6.8% between the numerical and the experimental values of the UTS.

scholarly journals Accuracy Assessment of Molded, Patient-Specific Polymethylmethacrylate Craniofacial Implants Compared to Their 3D Printed Originals

2020 ◽  
Vol 9 (3) ◽  
pp. 832 ◽  
Author(s):  
Dave Chamo ◽  
Bilal Msallem ◽  
Neha Sharma ◽  
Soheila Aghlmandi ◽  
Christoph Kunz ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Accuracy Assessment ◽  
Three Dimensional ◽  
Production Costs ◽  
Patient Specific ◽  
Patient Specific Implants ◽  
3D Printed ◽  
Cost Efficient ◽  
Craniofacial Implants ◽  
Aided Design

The use of patient-specific implants (PSIs) in craniofacial surgery is often limited due to a lack of expertise and/or production costs. Therefore, a simple and cost-efficient template-based fabrication workflow has been developed to overcome these disadvantages. The aim of this study is to assess the accuracy of PSIs made from their original templates. For a representative cranial defect (CRD) and a temporo-orbital defect (TOD), ten PSIs were made from polymethylmethacrylate (PMMA) using computer-aided design (CAD) and three-dimensional (3D) printing technology. These customized implants were measured and compared with their original 3D printed templates. The implants for the CRD revealed a root mean square (RMS) value ranging from 1.128 to 0.469 mm with a median RMS (Q1 to Q3) of 0.574 (0.528 to 0.701) mm. Those for the TOD revealed an RMS value ranging from 1.079 to 0.630 mm with a median RMS (Q1 to Q3) of 0.843 (0.635 to 0.943) mm. This study demonstrates that a highly precise duplication of PSIs can be achieved using this template-molding workflow. Thus, virtually planned implants can be accurately transferred into haptic PSIs. This workflow appears to offer a sophisticated solution for craniofacial reconstruction and continues to prove itself in daily clinical practice.

Design of special tools by CAD/CAM systems

1998 ◽  
Vol 212 (5) ◽  
pp. 357-371
Author(s):  
J C Rico ◽  
S Mateos ◽  
E Cuesta ◽  
C M Suárez
Keyword(s):  
Computer Aided Design ◽  
Automatic Identification ◽  
Automatic Design ◽  
Technological Parameters ◽  
Optimum Cutting ◽  
Cad Cam ◽  
The Cost ◽  
Aided Design ◽  
Cam Systems ◽  
Selection Of

This paper presents a program for the automatic design of special tools developed under a CAD/CAM (computer aided design/manufacture) system. In particular, the special tools made with standard components have been considered. Since the design of these types of tools was essentially related to the selection of their components, this paper deals with this aspect, insisting upon the selection of those components directly related to the removal of material: the toolholders or cartridges and the inserts. To select these components it is necessary to take into account not only geometrical or technological rules but also economical ones, owing to the high amount of possible components they can select. Consideration of economical aspects required the formulation of the cost equation associated with the use of these types of tools, characterized because their cutting edges coincide with different cutting velocities. Likewise, consideration of economical aspects allows the selection of the optimum cutting conditions and the cutting components to take place at the same time. Some of the geometrical and technological parameters related to the selection of cutting components are automatically identified by the system through an automatic identification of the workpiece profile.

Developments in the transtibial prosthetic socket fitting process: A review of past and present research

2000 ◽  
Vol 24 (2) ◽  
pp. 97-107 ◽  
Author(s):  
P. Sewell ◽  
S. Noroozi ◽  
J. Vinney ◽  
S. Andrews
Keyword(s):  
World War Ii ◽  
Computer Aided Design ◽  
Dramatic Improvement ◽  
Prosthetic Design ◽  
Element Analysis ◽  
Prosthetic Socket ◽  
Education Training ◽  
Research And Education ◽  
Aided Design ◽  
Socket Interface

A revolution in transtibial prosthetic design began at the end of World War II with the development of new materials and a dramatic improvement in the understanding of biomechanics. Early research was based mainly on the improvement of existing prosthetic design practice. Today, research has been focused on providing a better understanding of stump/socket interface biomechanics and improving socket fit by attempting to quantify the normal/direct stresses at the interface.The purpose of this review paper is to question whether research and prosthetic education/training to date has significantly improved our understanding of what makes a good socket. Although there is no doubt that advances in socket fitting techniques have been made what is not clear is the actual extent to which these advances have improved the quality of sockets fitted.It is suggested that a new approach is needed which can overcome some of the inherent problems of designing and manufacturing a comfortable high quality socket. It is also suggested that current research and education/training in the fields of pressure/interfacial interaction measurement and Finite Element Analysis techniques have limited potential to address many of these problems. There is also little evidence that current computer aided design systems offer any significant advantages over more conventional techniques.

Optimization of a Tire Traction Model for Antilock Brake System Simulations

1995 ◽  
Vol 117 (2) ◽  
pp. 199-204 ◽  
Author(s):  
J. R. Wagner
Keyword(s):  
Computer Aided Design ◽  
Cost Effective ◽  
Shear Forces ◽  
Data Simulation ◽  
Antilock Brake System ◽  
Road Surfaces ◽  
System Variables ◽  
The Cost ◽  
Aided Design ◽  
Selection Of

The cost effective design of antilock brake systems for automobiles requires the use of computer aided design and analysis techniques, as well as traditional invehicle testing. An important consideration in the simulation of the vehicle and brake dynamics is the generation of the shear forces and aligning torques at the tire/road interface. Frequently, experimental tire data gathered over a limited number of road surfaces is extrapolated to test antilock brake systems on a variety of roads. However, this approach may lead to problems in correlating the simulated system performance with actual vehicle tests. In this study, nonlinear programming strategies are applied to an analytical tire model to facilitate the selection of system variables. The formulation of an optimization problem to determine these variables permits the generation of shear forces which correspond fairly well with the empirical data. Simulation results are presented and discussed for five road surfaces to indicate the overall performance of this technique.

CAD-Based Calculation of Cutting Force Components in Gear Hobbing

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Tapoglou Nikolaos ◽  
Antoniadis Aristomenis
Keyword(s):  
Cutting Forces ◽  
Computer Aided Design ◽  
Simulation Code ◽  
Gear Hobbing ◽  
Involute Gears ◽  
Cutting Force Components ◽  
Force Components ◽  
The Cost ◽  
Aided Design

Gear hobbing is a common method of manufacturing high precision involute gears. The thorough knowledge of the developed cutting forces and the wear of the cutting tool are of great importance in order to produce helical and spur gears as they influence the cost of the manufacturing process and the quality of the produced gear. A novel simulation code called HOB3D was created in accordance with the above. This code can simulate the complex movements involved in gear hobbing with the best available accuracy, which is achieved by embedding the developed algorithm in a commercial computer aided design (CAD) environment. The simulation code calculates and exports the total cutting forces as well as the cutting forces in every cutting edge involved in the cutting process.

scholarly journals Effect of Printing Layer Thickness on the Trueness and Margin Quality of 3D-Printed Interim Dental Crowns

2021 ◽  
Vol 11 (19) ◽  
pp. 9246
Author(s):  
Gülce Çakmak ◽  
Alfonso Rodriguez Cuellar ◽  
Mustafa Borga Donmez ◽  
Martin Schimmel ◽  
Samir Abou-Ayash ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Computer Aided Design ◽  
3D Analysis ◽  
Hybrid Resin ◽  
Dental Crowns ◽  
Alignment Tool ◽  
Occlusal Surfaces ◽  
3D Printed ◽  
Aided Design

The information in the literature on the effect of printing layer thickness on interim 3D-printed crowns is limited. In the present study, the effect of layer thickness on the trueness and margin quality of 3D-printed composite resin crowns was investigated and compared with milled crowns. The crowns were printed in 3 different layer thicknesses (20, 50, and 100 μm) by using a hybrid resin based on acrylic esters with inorganic microfillers or milled from polymethylmethacrylate (PMMA) discs and digitized with an intraoral scanner (test scans). The compare tool of the 3D analysis software was used to superimpose the test scans and the computer-aided design file by using the manual alignment tool and to virtually separate the surfaces. Deviations at different surfaces on crowns were calculated by using root mean square (RMS). Margin quality of crowns was examined under a stereomicroscope and graded. The data were evaluated with one-way ANOVA and Tukey HSD tests. The layer thickness affected the trueness and margin quality of 3D-printed interim crowns. Milled crowns had higher trueness on intaglio and intaglio occlusal surfaces than 100 μm-layer thickness crowns. Milled crowns had the highest margin quality, while 20 μm and 100 μm layer thickness printed crowns had the lowest. The quality varied depending on the location of the margin.

scholarly journals PROGRAMS FOR COMPUTER MODELING OF MECHANISM KINEMATICS

2020 ◽  
Vol 7 (2) ◽  
pp. 037-048
Author(s):  
T. A. Sheveleva ◽  
Keyword(s):  
Computer Modeling ◽  
Computer Aided Design ◽  
Modern Technology ◽  
Cad Systems ◽  
Kinematic Study ◽  
Special Programs ◽  
History Of ◽  
Design Systems ◽  
The Cost ◽  
Aided Design

The article presents the history of the creation of computer-aided design systems, an overview of special programs and CAD systems for the kinematic study of mechanisms, as well as examples of the use of these programs in computer simulation of the movement of mechanisms. The urgency of this problem is determined by the need to perform synthesis and analysis of mechanisms that have found wide application in modern technology. The use of computer modeling for the kinematic study of mechanisms allows you to reduce the time for designing mechanisms, and with this the cost of the final product.

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