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1 – 10 of 54
Article
Publication date: 1 August 2011

H. Khlif and S. Ben Abdessalem

Textile prostheses made of polyethylene terephthalate fibers are commonly used to cure cardiovascular pathologies by replacing diseased arteries. Any failure of vascular surgery…

Abstract

Textile prostheses made of polyethylene terephthalate fibers are commonly used to cure cardiovascular pathologies by replacing diseased arteries. Any failure of vascular surgery is not only expensive, but also unacceptable. Biocompatibility, biofunctionality and biodurability must be taken into consideration especially with the increasing life expectancy of the population. An outstanding development of vascular prostheses might be achieved by a better choice of biomaterials and an optimization of manufacturing processes, especially the crimping technique. Crimping is an "accordion"-pleat deformation, which gives the graft a radial resistance and a longitudinal compliance. It also improves the resistance of the prosthesis to kinking and external compression. The aim of the present study is to compare the effect of three thermofixing techniques used for vascular prosthesis crimping. This will help to find the crimping process that leads to the lowest reduction of the mechanical performances of the material. We have demonstrated that the heat-setting in saturated vapor introduces the best mechanical behavior of crimped woven tubes in comparison to heat-settings with dry heat and boiling water.

Details

Research Journal of Textile and Apparel, vol. 15 no. 3
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 1 December 2004

George K. Stylios

Examines the tenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects…

3545

Abstract

Examines the tenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 16 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 December 2003

George K. Stylios

Examines the ninth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects…

1197

Abstract

Examines the ninth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 15 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 August 2003

R. Contro and P. Vena

This paper aims at showing that the finite element method is the most important numerical tool to analyse bio‐solids or bio‐fluids because of the constitutive complexity and…

1209

Abstract

This paper aims at showing that the finite element method is the most important numerical tool to analyse bio‐solids or bio‐fluids because of the constitutive complexity and unusual clinical input data and requirements involved. These features are absolutely mandatory and modify the mentality of an expert of FEM when he wants to contribute really to the progress of medical practice in their several forms, from biological basis to the surgical assistance. In this context, a clear view of the hierarchic importance of the phenomena involved is necessary to reply correctly to medical operators and to choose the right level of scale. While a scholarly culture of FEM and relative developments have to appeal the attention of biomedical engineers, at the same time their attention mainly is focused on the problem to solve, which must be validated clinically and experimentally. So while convergence remain a typical goal of the analyst, accuracy must be compared with the medical sensitivity. To do this, some physical conditions, less important in other application fields, as the boundary conditions, must be modelled in order to avoid that any model refinement gives unappreciable precision while tends to disregard what a clinician or a surgeon is able to understand and to use in the context of his professional practice. Setting up correct boundary conditions is an emblematic topic because it concerns a typical approach of computational methods applied to biomedical engineering which must consider two separate scale into analysis or a design approach. When a district of the body is to be analysed, the main goal should be to define correctly the subdomain that the district represents with respect to the whole and then to analyse other subdomains inside, at a level more and more micro, as into a system of Chinese boxes. When a medical device is to be designed a systemic view must be acquired. In this paper, we will start from this underlying feature concerning just FEM applications of a knee design carried out by the research staff of the Laboratory of Biological Structure Mechanics. Then other uses of FEM will be described as analysis fragments through problems studied by the authors and referenced in bibliography.

Details

Engineering Computations, vol. 20 no. 5/6
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 August 2006

Jiankang He, Dichen Li, Bingheng Lu, Zhen Wang and Tao Zhang

To present a custom design and fabrication method for a novel hemi‐knee joint substitute composed of titanium alloy and porous bioceramics based on rapid prototyping (RP) and…

2475

Abstract

Purpose

To present a custom design and fabrication method for a novel hemi‐knee joint substitute composed of titanium alloy and porous bioceramics based on rapid prototyping (RP) and rapid tooling (RT) techniques.

Design/methodology/approach

The three‐dimensional (3D) freeform model of a femur bone was reconstructed based on computerized tomography images via reverse engineering and the 3D reconstruction accuracy was evaluated. The negative image of artificial bone was designed with interconnected microstructures (250‐300 μm). The epoxy resin mould of a hemi‐knee joint and the negative pattern of an artificial bone were fabricated on Stereolithography apparatus. Based on these moulds, a titanium‐alloy hemi‐knee joint and a porous‐bioceramic artificial bone were created by quick casting and powder sintering (known as RT) techniques, respectively. After assembling, a composite hemi‐knee joint substitute was obtained.

Findings

The 3D reconstructed freeform model of the femur bone conformed to the original anatomy within a maximum deviation 0.206 mm. The sintered artificial bone had interconnected micropores (250 μm) and microchannels (300 μm). After implanting in vivo, the composite hemi‐knee joint substitute matched well with the surrounding tissues and bones with sufficient mechanical strength.

Research limitations/implications

Further in‐vivo research is needed to provide the evidence for tissue growth into the ceramic structures and long‐term viability and stability of the implant.

Originality/value

This method enhances the versatility of using RP in the fabrication of tissue‐engineered substitutes, especially when individual matching is considered. Although this paper took a customized hemi‐knee joint substitute as an example, it is capable of fabricating other artificial substitutes with a variety of biomaterials.

Details

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

Keywords

Article
Publication date: 3 March 2020

Asmaa F. Elelamy, Nasser S. Elgazery and R. Ellahi

This paper aims to investigate a mathematical model with numerical simulation for bacterial growth in the heart valve.

Abstract

Purpose

This paper aims to investigate a mathematical model with numerical simulation for bacterial growth in the heart valve.

Design/methodology/approach

For antibacterial activities and antibodies properties, nanoparticles have been used. As antibiotics are commonly thought to be homogeneously dispersed through the blood, therefore, non-Newtonian fluid of Casson micropolar blood flow in the heart valve for two dimensional with variable properties is used. The heat transfer with induced magnetic field translational attraction under the influence of slip is considered for the resemblance of the heart valve prosthesis. The numeral results have been obtained by using the Chebyshev pseudospectral method.

Findings

It is proven that vascular resistance decreases for increasing blood velocity. It is noted that when the magnetic field will be induced from the heart valve prosthesis then it may cause a decrease in vascular resistance. The unbounded molecules and antibiotic concentration that are able to penetrate the bacteria are increased by increasing values of vascular resistance. The bacterial growth density cultivates for upswing values of magnetic permeability and magnetic parameters.

Originality/value

To the best of the authors’ knowledge, this is the first study to investigate a mathematical model with numerical simulation for bacterial growth in the heart valve.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 11
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 17 October 2008

Rafael R. Torrealba, G. Fernández‐López and Juan C. Grieco

The aim is to set a state‐of‐the‐art in scientific research towards the development of knee prostheses for transfemoral amputees, by reviewing the literature in the field and by…

2250

Abstract

Purpose

The aim is to set a state‐of‐the‐art in scientific research towards the development of knee prostheses for transfemoral amputees, by reviewing the literature in the field and by identifying different scientific research lines that have brought out through the years. Also, to provide the information about possible outcomes in the near future, and their links to cybernetics, given the present trends in the field.

Design/methodology/approach

Literature related to scientific research carried out up‐to‐date in the field of knee prostheses, is reviewed in scientific articles, books and electronic sources. Then, different research lines are identified from the obtained information, and finally classified as presented in this work.

Findings

Three scientific research lines regarding the development of knee prostheses were found, each one dealing with: the design of knee prostheses; the performance assessment of these prostheses; and the creation of control strategies for these prostheses which use electronics to control their performance. Also, two new possible eras of prostheses were encountered: the cybernetic era, and the electromyographic one. Considering both options, it is concluded that the cybernetic era of prostheses is likely to become real soon.

Practical implications

A useful state‐of‐the‐art review for researchers likely to be introduced in the field of development of knee prostheses and prosthetic technology in general.

Originality/value

This literature review not only sets a state‐of‐the‐art of the development of knee prostheses, but also proposes a frame of references which allows to classify the different works done in the field, as well as a better understanding of these through a clear presentation.

Details

Kybernetes, vol. 37 no. 9/10
Type: Research Article
ISSN: 0368-492X

Keywords

Open Access
Article
Publication date: 28 August 2021

Luca Gabriele De Vivo Nicoloso, Joshua Pelz, Herb Barrack and Falko Kuester

There are over 40 million amputees globally with more than 185,000 Americans losing their limbs every year. For most of the world, prosthetic devices remain too expensive and…

2766

Abstract

Purpose

There are over 40 million amputees globally with more than 185,000 Americans losing their limbs every year. For most of the world, prosthetic devices remain too expensive and uncomfortable. This paper aims to outline advancements made by a multidisciplinary research group, interested in advancing the restoration of human motion through accessible lower limb prostheses.

Design/methodology/approach

Customization, comfort and functionality are the most important metrics reported by prosthetists and patients. The work of this paper presents the design and manufacturing of a custom made, cost-effective and functional three-dimensional (3D) printed transtibial prosthesis monocoque design. The design of the prosthesis integrates 3D imaging, modelling and optimization techniques coupled with additive manufacturing.

Findings

The successful fabrication of a functional monocoque prosthesis through 3D printing indicates the workflow may be a solution to the worldwide accessibility crisis. The digital workflow developed in this work offers great potential for providing prosthetic devices to rural communities, which lack access to skilled prosthetic physicians. The authors found that using the workflow together with 3D printing, this study can create custom monocoque prostheses (Figure 16). These prostheses are comfortable, functional and properly aligned. In comparison with traditional prosthetic devices, the authors slowered the average cost, weight and time of production by 95%, 55% and 95%, respectively.

Social implications

This novel digital design and manufacturing workflow has the potential to democratize and globally proliferate access to prosthetic devices, which restore the patient’s mobility, quality of life and health. LIMBER’s toolbox can reach places where proper prosthetic and orthotic care is not available. The digital workflow reduces the cost of making custom devices by an order of magnitude, enabling broader reach, faster access and improved comfort. This is particularly important for children who grow quickly and need new devices every few months or years, timely access is both physically and psychologically important.

Originality/value

In this manuscript, the authors show the application of digital design techniques for fabricating prosthetic devices. The proposed workflow implements several advantageous changes and, most importantly, digitally blends the three components of a transtibial prosthesis into a single, 3D printable monocoque device. The development of a novel unibody transtibial device that is properly aligned and adjusted digitally, greatly reduces the number of visits an amputee must make to a clinic to have a certified prosthetist adjust and modify their prosthesis. The authors believe this novel workflow has the potential to ease the worldwide accessibility crisis for prostheses.

Details

Rapid Prototyping Journal, vol. 27 no. 11
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 April 1992

JAROSLAV MACKERLE

This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE…

Abstract

This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE) applications in different fields of biomechanics between 1976 and 1991. The aim of this paper is to help the users of FE and BE techniques to get better value from a large collection of papers on the subjects. Categories in biomechanics included in this survey are: orthopaedic mechanics, dental mechanics, cardiovascular mechanics, soft tissue mechanics, biological flow, impact injury, and other fields of applications. More than 900 references are listed.

Details

Engineering Computations, vol. 9 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 February 2000

Chua Chee Kai, Chou Siaw Meng, Lin Sin Ching, Lee Seng Teik and Saw Chit Aung

While computerized tomography (CT) and magnetic resonance imaging (MRI) technologies are highly commendable for their applications and usage, sometimes cases involving facial…

8159

Abstract

While computerized tomography (CT) and magnetic resonance imaging (MRI) technologies are highly commendable for their applications and usage, sometimes cases involving facial anatomy restoration may not necessarily require these highly sophisticated technologies. A suitable replacement that is also non‐contact and allows fast image capture is the laser digitizer surface scanner. This scanner takes only seconds to capture an image of the patient’s sound or healthy facial anatomy. By using the captured image data, it is possible, with the help of a surface data modeller rapid prototyping (RP) machine and vacuum casting machine, to manufacture the prosthesis for implant. Presents a novel approach for facial prosthesis fabrication through a case study of a prosthetic ear model using an integrated manufacturing system comprising the laser surface digitizer, surface data modeller, rapid prototyping system and vacuum casting system.

Details

Integrated Manufacturing Systems, vol. 11 no. 1
Type: Research Article
ISSN: 0957-6061

Keywords

1 – 10 of 54