scholarly journals Rapid prototyping of replica knee implants for in vitro testing

2016 ◽  
Vol 2 (1) ◽  
pp. 553-556 ◽  
Author(s):  
Mark Verjans ◽  
Malte Asseln ◽  
Klaus Radermacher

AbstractThe understanding of the complex biomechanics of the knee is a key for an optimal implant design. To easily investigate the influence of prosthetic designs on knee biomechanics a rapid prototyping workflow for knee implants has been developed and evaluated. Therefore, different manufacturing technologies and post-treatment methods have been examined and overall seven different replica knee implants were manufactured. For evaluation, the manufacturing properties such as surface accuracy and roughness were determined and kinematic behaviour was investigated in a novel knee testing rig. It was carried out that PolyJet-Modelling with a sanded surface resulted in changed kinematic patterns compared to a usual CoCr-UHMWPE implant. However, fused deposition modelling using ABS and subsequent surface smoothening with acetone vapor showed the lowest roughness of the manufactured implants and only minor kinematic differences. For this reason this method constitutes a promising approach towards an optimal implant design for improved patient-satisfaction and long lifetime of the implant. Finally the workflow is not only limited to the knee.

2018 ◽  
Vol 7 (3.17) ◽  
pp. 90
Author(s):  
Khurram Altaf ◽  
Masri Baharom ◽  
A Rashid A. Aziz ◽  
Junaid A. Qayyum ◽  
Mirza Jahanzaib

A novel internal combustion engine termed as Crank Rocker Engine has been developed at Universiti Teknologi PETRONAS (UTP) Malaysia. In the existing design, the engine cylinder is cooled through forced convection which is not efficient and malfunctioning of cooling system could lead to engine overheating. The objective of the current study is to develop a concept of an integrated and customized cooling system for the Crank-Rocker engine and to develop through rapid prototyping (RP). The proposed cooling system comprises of an integrated cooling water jacket around the engine cylinder, which works on the principle of forced convection. The forced convection is energy intensive and not suitable for stationary engines. Therefore, an enhanced design of the cooling system is required to improve the overall performance of the engine. Since the engine cylinder is curved, the conventional manufacturing technologies could be difficult to apply for the development of cooling system. For swift, precise and economic development as well as performance analysis of the cooling system, RP technique could be promising. In the present study, a customized and modified cooling system has been designed and developed through fused deposition modelling (FDM), an efficient RP technology. Design for additive manufacturing (DFAM) is applied to mitigate development time and support structures of the cooling system. The design is proposed by keeping in view the cooling performance and manufacturability. 


2018 ◽  
Vol 941 ◽  
pp. 2154-2159 ◽  
Author(s):  
Antonio Lanzotti ◽  
Massimo Martorelli ◽  
Teresa Russo ◽  
Antonio Gloria

Additive Manufacturing technologies allow for the direct fabrication of lightweight structures with improved properties. In this context, Fused Deposition Modelling (FDM) has also been considered to design 3D multifunctional scaffolds with complex morphology, tailored biological, mechanical and mass transport properties. As an example, poly (ε-caprolactone) (PCL), surface-modified PCL and PCL-based nanocomposite scaffolds were fabricated and analysed. The effects of structural and morphological features (i.e., sequence of stacking, fiber spacing distance, pore size and geometry), surface modification and nanoparticles on the in vitro biological and mechanical performances were investigated.


2015 ◽  
Vol 21 (1) ◽  
pp. 56-69 ◽  
Author(s):  
M. Jiménez ◽  
L. Romero ◽  
M. Domínguez ◽  
M.M. Espinosa

Purpose – This paper aims to present an optimal prototyping technology for the manufacture of occlusal splints. Design/methodology/approach – To carry out this study, a comparative technique was used to analyze models obtained by different prototyping techniques. Subsequently, further tests were carried out with respect to the manufacturing of splints by means of thermoforming in a vacuum. This involved an analysis of the most important variables such as prototype material, geometric accuracy, surface finish and costs. Findings – It was found that there is a group of prototyping technologies that are suitable for the manufacture of the models used in the thermoforming of correction splints, the most appropriate technologies being based on ink jet printing (IJP-Objet), ultraviolet photo polymerization and fused deposition modelling due to the fact that they offer an optimal relationship between the cost and the quality of the model required for thermoforming. Practical implications – The application of rapid prototyping techniques in medicine makes the production of physical models from three-dimensional medical image processing and their subsequent use in different specialties possible. It also makes preoperative planning processes, the production of prostheses and the preparation of surgical templates possible, thereby offering a higher quality of diagnosis, safer surgery and cost and time savings compared to conventional manufacturing technologies. Originality/value – This paper suggests that there exists a group of prototyping technologies for the manufacture of splints that offer advantages over existing technologies. The results also suggest that, in many cases, the most expensive technology is not the most appropriate: there are other options that provide an optimal model in terms of the cost and the quality needed for thermoforming.


2015 ◽  
Vol 21 (6) ◽  
pp. 735-746 ◽  
Author(s):  
Janusz Domanski ◽  
Konstanty Skalski ◽  
Roman Grygoruk ◽  
Adrian Mróz

Purpose – The purpose of this paper is to present the methodology of a design process of new lumbar intervertebral disc implants with specific emphasis on the use of rapid prototyping technologies. The verification of functionality of artificial intervertebral discs is also given. The paper describes the attempt and preliminary research to evaluate the properties of the intervertebral disc implant prototypes manufactured with the use of different rapid prototyping technologies, i.e. FDM – fused deposition modelling, 3DP – 3D printing and SLM – selective laser melting. Design/methodology/approach – Based on the computed tomography (CT) scan data, the anatomical parameters of lumbar spine bone tissue were achieved, which were the bases for the design-manufacture process carried out with the use of computer-aided designing/computer-aided engineering/computer-aided manufacturing systems. In the intervertebral disc implant design process, three RP technologies: FDM, 3DP and SLM were used for solving problems related to the reconstruction of geometry and functionality of the disc. Some preliminary tests such as measurement of roughness and structural analyses of material of prototypes made by different prototyping technologies were performed. Findings – This paper allowed the authors to elaborate and patent two new intervertebral disc implants. Because the implant designs are parametrical ones with relation to lumbar bone tissue properties measured on CT scans, they can be also made for individual patients. We also compared some of the properties of intervertebral implants prototypes made with the use of FDM, 3DP and SLM technologies. Originality/value – The paper presents the new intervertebral disc implants and their manufacturing by rapid prototyping. The methodology of designing intervertebral disc implant is shown. Some features of the methodology make it useful for preoperative planning of intervertebral disc surgery, as well.


2018 ◽  
Vol 184 ◽  
pp. 02013
Author(s):  
Tamás Templom ◽  
Timotei István Erdei ◽  
Zsolt Molnár ◽  
Edwin Shaw ◽  
Géza Husi

The pinnacle of 3D printing is its effect on the field of rapid prototyping. The major advantage comes from the fact that designers can quickly materialize a part or object, which then could be tested in practice, and can be effortlessly modified if needed. This obviously cuts the development expenses and time by a significant percent. Moreover, it’s possible to create complex and precise shapes with the technology, which would take more time and would be resource intensive if done by older methods, for example manual or automatic machining.


2020 ◽  
pp. 088532822097849
Author(s):  
Xiao Han ◽  
Yuan Gao ◽  
Yilei Ding ◽  
Weijie Wang ◽  
Li Liu ◽  
...  

Spinal fusion cages are commonly used to treat spinal diseases caused by degenerative changes, deformities, and trauma. At present, most of the main clinical spinal fusion cage products are non-degradable and still cause some undesirable side effects, such as the stress shielding phenomenon, interference with postoperative medical imaging, and obvious foreign body sensation in patients. Degradable spinal fusion cages have promising potential with extensive perspectives. The purpose of this study was to fabricate a degradable spinal fusion cage from both polycaprolactone (PCL) and high-proportion beta-tricalcium phosphate (β-TCP), using the highly personalised, accurate, and rapid fused deposition modelling 3 D printing technology. PCL and β-TCP were mixed in three different ratios (60:40, 55:45, and 50:50). Both in vitro degradation and cell experiments proved that all cages with the different PCL:β-TCP ratios met the mechanical properties of human cancellous bone while maintaining their structural integrity. The biological activity of the cages improved with higher amounts of the β-TCP content. This study also showed that a spinal fusion cage with high β-TCP content and suitable mechanical properties can be manufactured using extruding rods and appropriate models, providing a new solution for the design of degradable spinal fusion cages.


2010 ◽  
Vol 441 ◽  
pp. 155-179 ◽  
Author(s):  
Ulrike Deisinger

For tissue regeneration in medicine three-dimensional scaffolds with specific characteristics are required. A very important property is a high, interconnecting porosity to enable tissue ingrowth into the scaffold. Pore size distribution and pore geometry should be adapted to the respective tissue. Additionally, the scaffolds should have a basic stability for handling during implantation, which is provided by ceramic scaffolds. Various methods to produce such ceramic 3D scaffolds exist. In this paper conventional and new fabrication techniques are reviewed. Conventional methods cover the replica of synthetic and natural templates, the use of sacrificial templates and direct foaming. Rapid prototyping techniques are the new methods listed in this work. They include fused deposition modelling, robocasting and dispense-plotting, ink jet printing, stereolithography, 3D-printing, selective laser sintering/melting and a negative mould technique also involving rapid prototyping. The various fabrication methods are described and the characteristics of the resulting scaffolds are pointed out. Finally, the techniques are compared to find out their disadvantages and advantages.


2013 ◽  
Vol 308 ◽  
pp. 25-31 ◽  
Author(s):  
Ludmila Novakova-Marcincinova ◽  
Jozef Novak-Marcincin

This paper deals with basic knowledge and problems in area of Rapid Prototyping (RP) technology operation focused on used material testing and operation optimization from economical aspects of view. It belongs to progressive methods of model creation based on geometry obtained from CAD environment with application possibilities in different industrial spheres. Chapters are focused on optimization of Rapid Prototyping preparation and operation process. There also is algorithm that leads to selection of suitable RP operation settings. Utilization of algorithm is presented on case of part production with use of UPrint device and Catalyst software, system created for utilization of Fused Deposition Modelling (FDM) technology.


2013 ◽  
Vol 464 ◽  
pp. 399-405 ◽  
Author(s):  
Ludmila Novakova-Marcincinova ◽  
Jozef Novak-Marcincin

Rapid Prototyping (RP) presents the automatic production of physical parts using by additive manufacturing technology. The start techniques for Rapid Prototyping became available in the late 1980s and were used to produce models and prototype parts. Today they are used for a much wider range of applications and are even used to manufacture production-quality parts in relatively small numbers. Rapid Prototyping is widely used in the automotive, aerospace, medical, and consumer products industries. In paper is presented process of design product development, product production and testing of products produced by Fused Deposition Modelling rapid prototyping technology.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Michele Gabrio Antonelli ◽  
Pierluigi Beomonte Zobel ◽  
Francesco Durante ◽  
Terenziano Raparelli

This paper describes the results of research projects developed at the University of L’Aquila by the research group of the authors in the field of biomedical engineering, which have seen an important use of additive manufacturing technologies in the prototyping step and, in some cases, also for the realization of preindustrialization prototypes. For these projects, commercial 3D printers and technologies such as fused deposition modelling (FDM) were used; the most commonly used polymers in these technologies are acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). The research projects concern the development of innovative actuators, such as pneumatic muscles and soft pneumatic actuators (SPAs), the development of active orthoses, such as a lower limb orthosis and, finally, the development of a variable-stiffness grasper to be used in natural orifice transluminal endoscopic surgery (NOTES). The main aspects of these research projects are described in the paper, highlighting the technologies used such as the finite element analysis and additive manufacturing.


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