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Article
Publication date: 1 August 2003

Liu Yaxiong, Li Dichen, Lu Bingheng, He Sanhu and Li Gang

Traditional standard bone substitutes cannot realize the individualized matching for the bones of different patients. In order to make a bone substitute match the shape of a…

1191

Abstract

Traditional standard bone substitutes cannot realize the individualized matching for the bones of different patients. In order to make a bone substitute match the shape of a patient's bone easily, a technology based on reverse engineering (RE) and rapid prototyping (RP) is put forward to design and fabricate a customized bone substitute. By RE, the customized bone substitute is designed according to the CT sectional pictures, and the customized localizer is designed to locate the customized bone substitute in the patient's body at the right position. A customized mandible substitute designed and fabricated by RE and RP has been put into clinical use and is discussed in detail. The results confirm that the advantage of RP in the field of bone restoration is that it can fabricate the customized bone substitute rapidly and accurately.

Details

Rapid Prototyping Journal, vol. 9 no. 3
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 19 July 2021

Xiaojing Feng, Bin Cui, Yaxiong Liu, Lianggang Li, Xiaojun Shi and Xiaodong Zhang

The purpose of this paper is to solve the problems of poor mechanical properties, high surface roughness and waste support materials of thin-walled parts fabricated by…

466

Abstract

Purpose

The purpose of this paper is to solve the problems of poor mechanical properties, high surface roughness and waste support materials of thin-walled parts fabricated by flat-layered additive manufacturing process.

Design/methodology/approach

This paper proposes a curved-layered material extrusion modeling process with a five-axis motion mechanism. This process has advantages of the platform rotating, non-support printing and three-dimensional printing path. First, the authors present a curved-layered algorithm by offsetting the bottom surface into a series of conformal surfaces and a toolpath generation algorithm based on the geodesic distance field in each conformal surface. Second, they introduce a parallel five-axis printing machine consisting of a printing head fixed on a delta-type manipulator and a rotary platform on a spherical parallel machine.

Findings

Mechanical experiments show the failure force of the five-axis printed samples is 153% higher than that of the three-axis printed samples. Forming experiments show that the surface roughness significantly decreases from 42.09 to 18.31 µm, and in addition, the material consumption reduces by 42.90%. These data indicate the curved-layered algorithm and five-axis motion mechanism in this paper could effectively improve mechanical properties and the surface roughness of thin-walled parts, and realize non-support printing. These methods also have reference value for other additive manufacturing processes.

Originality/value

Previous researchers mostly focus on printing simple shapes such as arch or “T”-like shape. In contrast, this study sets out to explore the algorithm and benefits of modeling thin-walled parts by a five-axis machine. Several validated models would allow comparability in five-axis printing.

Details

Rapid Prototyping Journal, vol. 27 no. 7
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 16 January 2009

Sekou Singare, Qin Lian, Wei Ping Wang, Jue Wang, Yaxiong Liu, Dichen Li and Bingheng Lu

This paper aims to describe computer‐aided design and rapid prototyping (RP) systems for the preoperative planning and fabrication of custom‐made implant.

2283

Abstract

Purpose

This paper aims to describe computer‐aided design and rapid prototyping (RP) systems for the preoperative planning and fabrication of custom‐made implant.

Design/methodology/approach

A patient with mandible defect underwent reconstruction using custom‐made implant. 3D models of the patient's skull are generated based on computed tomography image data. After evaluation of the 3D reconstructed image, it was identified that some bone fragment was moved due to the missing segment. During the implant design process, the correct position of the bone fragment was defined and the geometry of the custom‐made implant was generated based on mirror image technique and is fabricated by a RP machine. Surgical approach such as preoperative planning and simulation of surgical procedures was performed using the fabricated skull models and custom‐made implant.

Findings

Results show that the stereolithography model provided an accurate tool for preoperative, surgical simulation.

Research limitations/implications

The methods described above suffer from the expensive cost of RP technique.

Practical implications

This method allows accurate fabrication of the implant. The advantages of using this technique are that the physical model of the implant is fitted on the skull model so that the surgeon can plan and rehearse the surgery in advance and a less invasive surgical procedure and less time‐consuming reconstructive and an adequate esthetic can result.

Originality/value

The method improves the reconstructive surgery and reduces the risk of a second intervention, and the psychological stress of the patient will be eliminated.

Details

Rapid Prototyping Journal, vol. 15 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 August 2006

Sekou Singare, Liu Yaxiong, Li Dichen, Lu Bingheng, He Sanhu and Li Gang

This paper describes computer‐aided design (CAD) and rapid prototyping (RP) systems for the fabrication of maxillofacial implant.

2086

Abstract

Purpose

This paper describes computer‐aided design (CAD) and rapid prototyping (RP) systems for the fabrication of maxillofacial implant.

Design/methodology/approach

Design methods for medical RP of custom‐fabricated are presented in this paper. Helical computed tomography (CT) data were used to create a three‐dimensional model of the patient skull. Based on these data, the individual shape of the implant was designed in CAD environment and fabricate by RP process. One patient with a large mandible defect underwent reconstruction with individual prefabricated implant resulting from initial surgical failure with hand contoured reconstruction plate.

Findings

Results shows that the custom made implant fit well the defect. Overall, excellent mandible symmetry and stability were achieved with the custom made implants. The patient was able to eat. There was no saliva drooling after the reconstruction. The operating time was reduced.

Research limitations/implications

The methods described above suffer from the expensive cost of RP technique.

Practical implications

This method allows accurate fabrication of the implant. The advantages of using this technique are that the physical model of the implant is fitted on the skull model so that the surgeon can plan and rehearse the surgery in advance and a less invasive surgical procedure and less time‐consuming reconstructive and an adequate esthetic can result.

Originality/value

The method improves the reconstructive surgery and reduces the risk of a second intervention, and the psychological stress of the patient will be eliminated.

Details

Rapid Prototyping Journal, vol. 12 no. 4
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 23 October 2023

Yerui Fan, Yaxiong Wu and Jianbo Yuan

This study aims to improve the muscle model control performance of a tendon-driven musculoskeletal system (TDMS) to overcome disadvantages such as multisegmentation and strong…

76

Abstract

Purpose

This study aims to improve the muscle model control performance of a tendon-driven musculoskeletal system (TDMS) to overcome disadvantages such as multisegmentation and strong coupling. An adaptive network controller (ANC) with a disturbance observer is established to reduce the modeling error of the musculoskeletal model and improve its antidisturbance ability.

Design/methodology/approach

In contrast to other control technologies adopted for musculoskeletal humanoids, which use geometric relationships and antagonist inhibition control, this study develops a method comprising of three parts. (1) First, a simplified musculoskeletal model is constructed based on the Taylor expansion, mean value theorem and Lagrange–d’Alembert principle to complete the decoupling of the muscle model. (2) Next, for this simplified musculoskeletal model, an adaptive neuromuscular controller is designed to acquire the muscle-activation signal and realize stable tracking of the endpoint of the muscle-driven robot relative to the desired trajectory in the TDMS. For the ANC, an adaptive neural network controller with a disturbance observer is used to approximate dynamical uncertainties. (3) Using the Lyapunov method, uniform boundedness of the signals in the closed-loop system is proved. In addition, a tracking experiment is performed to validate the effectiveness of the adaptive neuromuscular controller.

Findings

The experimental results reveal that compared with other control technologies, the proposed design techniques can effectively improve control accuracy. Moreover, the proposed controller does not require extensive considerations of the geometric and antagonistic inhibition relationships, and it demonstrates anti-interference ability.

Originality/value

Musculoskeletal robots with humanoid structures have attracted considerable attention from numerous researchers owing to their potential to avoid danger for humans and the environment. The controller based on bio-muscle models has shown great performance in coordinating the redundant internal forces of TDMS. Therefore, adaptive controllers with disturbance observers are designed to improve the immunity of the system and thus directly regulate the internal forces between the bio-muscle models.

Details

Robotic Intelligence and Automation, vol. 43 no. 6
Type: Research Article
ISSN: 2754-6969

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Article
Publication date: 23 September 2024

FaGuang Jiang, Kebing Chen, Yang Chen and Cheng Tian

In response to the challenges posed by the conventional manual flange docking method in the LNG (Liquefied Natural Gas) loading process, such as low positioning accuracy…

41

Abstract

Purpose

In response to the challenges posed by the conventional manual flange docking method in the LNG (Liquefied Natural Gas) loading process, such as low positioning accuracy, constraints on production efficiency and safety hazards, this study analyzed the LNG five-axis loading arm’s main functions and structural characteristics.

Design/methodology/approach

An automated solution for the joints of the LNG loading arm was designed. The forward kinematic model of the LNG loading arm was established using the Denavit–Hartenberg (D-H) parameter method, and its workspace was analyzed. The Newton–Raphson iteration method was employed to solve the inverse kinematics of the LNG loading arm, facilitating trajectory planning. The relationship between the target position and the joint variables was established to verify the stability of the arm’s motion. Flange center identification was achieved using the Hough transform function. Based on the ROS platform, combined with Gazebo and Rviz, an experimental simulation of automatic docking of the LNG loading arm was conducted.

Findings

The docking errors in the XYZ directions were all less than 0.8 mm, meeting the required docking accuracy. Moreover, the motion performance of the loading arm during docking was smooth and free of abrupt changes, validating its capability to accomplish the automatic docking task.

Originality/value

The proposed trajectory planning and automatic docking scheme can be used for the rapid filling of LNG filling arms and LNG tankers to improve the efficiency of LNG transportation. In guiding the docking, the proposed automatic docking scheme is an accurate and efficient way to improve safety.

Details

Engineering Computations, vol. 41 no. 8/9
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 August 2008

Esfandyar Kouhi, Syed Masood and Yos Morsi

Combination of advanced imaging, designing and manufacturing techniques has been rapidly developed in recent years for diagnostic and therapeutic purposes for medical devices. The…

1260

Abstract

Purpose

Combination of advanced imaging, designing and manufacturing techniques has been rapidly developed in recent years for diagnostic and therapeutic purposes for medical devices. The purpose of this paper is to present a methodology for design and fabrication procedure of medical models using computer‐aided design (CAD) and fused deposition modeling (FDM) technique for application in the mandibular reconstructive surgery.

Design/methodology/approach

Case studies of patients with mandibular defects are examined using CAD model construction including data acquisition from computerized tomography scan and data processing. Furthermore, the effect of advanced manufacturing parameters settings in FDM methodology is investigated.

Findings

The models were used in assisting the surgeons in their reconstruction planning. A significant improvement regarding the success and convenience in surgery planning been reported.

Originality/value

This paper explores the application and viability of FDM rapid prototyping technology for fabrication of complex mandibular models used for reconstructive surgery.

Details

Assembly Automation, vol. 28 no. 3
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 1 December 2005

Xiang Li, Dichen Li, Bingheng Lu, Yiping Tang, Lin Wang and Zhen Wang

To fabricate the self‐hardening calcium phosphate composite scaffolds with controlled internal pore architectures using rapid prototyping (RP) techniques and investigate their in

1621

Abstract

Purpose

To fabricate the self‐hardening calcium phosphate composite scaffolds with controlled internal pore architectures using rapid prototyping (RP) techniques and investigate their in vitro bone tissue engineering responses.

Design/methodology/approach

The three‐dimensionally interconnected pores in scaffolds can facilitate sufficient supply of blood, oxygen and nutrients for the ingrowth of bone cells, tissue regeneration, and vascularization. It is essential for bone tissue engineering to provide an accurate control over the scaffolds material, porosity, and internal pore architectures. Negative image of scaffold was designed and epoxy resin molds were fabricated on sterolithography apparatus. Calcium phosphate cement slurry was cast in these molds. After self‐hardening, the molds were removed by pyrolysis and the resulting scaffolds were obtained.

Findings

Eight scaffolds with 54.45 percent porosity were tested on an Instron machine. The average compressive strength measured was 5.8±0.8 Mpa. Cytotoxicity and cell proliferation studies were conducted with rabbit osteoblast. Results showed that these scaffolds were non‐toxic and displayed excellent cell growth during the 2 weeks of in vitro culture.

Research limitations/implications

The resulting scaffolds inherited errors and defects from the molds, such as cracks and dimensional changes.

Originality/value

The present method enhances the versatility of scaffold fabrication by RP. It is capable of reproducibly fabricating scaffolds from a variety of biomaterials.

Details

Rapid Prototyping Journal, vol. 11 no. 5
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 12 December 2023

Mustafa Çimen, Damla Benli, Merve İbiş Bozyel and Mehmet Soysal

Vehicle allocation problems (VAPs), which are frequently confronted in many transportation activities, primarily including but not limited to full truckload freight transportation…

607

Abstract

Purpose

Vehicle allocation problems (VAPs), which are frequently confronted in many transportation activities, primarily including but not limited to full truckload freight transportation operations, induce a significant economic impact. Despite the increasing academic attention to the field, literature still fails to match the needs of and opportunities in the growing industrial practices. In particular, the literature can grow upon the ideas on sustainability, Industry 4.0 and collaboration, which shape future practices not only in logistics but also in many other industries. This review has the potential to enhance and accelerate the development of relevant literature that matches the challenges confronted in industrial problems. Furthermore, this review can help to explore the existing methods, algorithms and techniques employed to address this problem, reveal directions and generate inspiration for potential improvements.

Design/methodology/approach

This study provides a literature review on VAPs, focusing on quantitative models that incorporate any of the following emerging logistics trends: sustainability, Industry 4.0 and logistics collaboration.

Findings

In the literature, sustainability interactions have been limited to environmental externalities (mostly reducing operational-level emissions) and economic considerations; however, emissions generated throughout the supply chain, other environmental externalities such as waste and product deterioration, or the level of stakeholder engagement, etc., are to be monitored in order to achieve overall climate-neutral services to the society. Moreover, even though there are many types of collaboration (such as co-opetition and vertical collaboration) and Industry 4.0 opportunities (such as sharing information and comanaging distribution operations) that could improve vehicle allocation operations, these topics have not yet received sufficient attention from researchers.

Originality/value

The scientific contribution of this study is twofold: (1) This study analyses decision models of each reviewed article in terms of decision variable, constraint and assumption sets, objectives, modeling and solving approaches, the contribution of the article and the way that any of sustainability, Industry 4.0 and collaboration aspects are incorporated into the model. (2) The authors provide a discussion on the gaps in the related literature, particularly focusing on practical opportunities and serving climate-neutrality targets, carried out under four main streams: logistics collaboration possibilities, supply chain risks, smart solutions and various other potential practices. As a result, the review provides several gaps in the literature and/or potential research ideas that can improve the literature and may provide positive industrial impacts, particularly on how logistics collaboration may be further engaged, which supply chain risks are to be incorporated into decision models, and how smart solutions can be employed to cope with uncertainty and improve the effectiveness and efficiency of operations.

Details

The International Journal of Logistics Management, vol. 35 no. 3
Type: Research Article
ISSN: 0957-4093

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Article
Publication date: 8 June 2012

Mohammad Vaezi, Chee Kai Chua and Siaw Meng Chou

Today, medical models can be made by the use of medical imaging systems through modern image processing methods and rapid prototyping (RP) technology. In ultrasound imaging…

1244

Abstract

Purpose

Today, medical models can be made by the use of medical imaging systems through modern image processing methods and rapid prototyping (RP) technology. In ultrasound imaging systems, as images are not layered and are of lower quality as compared to those of computerized tomography (CT) and magnetic resonance imaging (MRI), the process for making physical models requires a series of intermediate processes and it is a challenge to fabricate a model using ultrasound images due to the inherent limitations of the ultrasound imaging process. The purpose of this paper is to make high quality, physical models from medical ultrasound images by combining modern image processing methods and RP technology.

Design/methodology/approach

A novel and effective semi‐automatic method was developed to improve the quality of 2D image segmentation process. In this new method, a partial histogram of 2D images was used and ideal boundaries were obtained. A 3D model was achieved using the exact boundaries and then the 3D model was converted into the stereolithography (STL) format, suitable for RP fabrication. As a case study, the foetus was chosen for this application since ultrasonic imaging is commonly used for foetus imaging so as not to harm the baby. Finally, the 3D Printing (3DP) and PolyJet processes, two types of RP technique, were used to fabricate the 3D physical models.

Findings

The physical models made in this way proved to have sufficient quality and shortened the process time considerably.

Originality/value

It is still a challenge to fabricate an exact physical model using ultrasound images. Current commercial histogram‐based segmentation method is time‐consuming and results in a less than optimum 3D model quality. In this research work, a novel and effective semi‐automatic method was developed to select the threshold optimum value easily.

Details

Rapid Prototyping Journal, vol. 18 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

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