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Article
Publication date: 25 September 2009

Richard Bibb, Dominic Eggbeer, Peter Evans, Alan Bocca and Adrian Sugar

The computer‐aided design (CAD) and manufacture of custom‐fitting surgical guides have been shown to provide an accurate means of transferring computer‐aided planning to…

Abstract

Purpose

The computer‐aided design (CAD) and manufacture of custom‐fitting surgical guides have been shown to provide an accurate means of transferring computer‐aided planning to surgery. To date guides have been produced using fragile materials via rapid prototyping techniques such as stereolithography (SLA), which typically require metal reinforcement to prevent damage from drill bits. The purpose of this paper is to report case studies which explore the application of selective laser melting (SLM) to the direct manufacture of stainless steel surgical guides. The aim is to ascertain whether the potential benefits of enhanced rigidity, increased wear resistance (negating reinforcement) and easier sterilisation by autoclave can be realised in practice.

Design/methodology/approach

A series of clinical case studies are undertaken utilising medical scan data, CAD and SLM. The material used is 316L stainless steel, an alloy typically used in medical and devices and surgical instruments. All treatments are planned in parallel with existing techniques and all guides are test fitted and assessed on SLA models of the patients' anatomy prior to surgery.

Findings

This paper describes the successful application of SLM to the production of stainless steel surgical guides in four different maxillofacial surgery case studies. The cases reported address two types of procedure, the placement of osseointegrated implants for prosthetic retention and Le Fort 1 osteotomies using internal distraction osteogenesis. The cases reported here have demonstrated that SLM is a viable process for the manufacture of custom‐fitting surgical guides.

Practical implications

The cases have identified that the effective design of osteotomy guides requires further development and refinement.

Originality/value

This paper represents the first reported applications of SLM technology to the direct manufacture of stainless steel custom‐fitting surgical guides. Four successful exemplar cases are described including guides for osteotomy as well as drilling. Practical considerations are presented along with suggestions for further development.

Details

Rapid Prototyping Journal, vol. 15 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 20 April 2015

Abby Megan Paterson, Richard Bibb, R. Ian Campbell and Guy Bingham

– The purpose of this paper is to compare four different additive manufacturing (AM) processes to assess their suitability in the context of upper extremity splinting.

Abstract

Purpose

The purpose of this paper is to compare four different additive manufacturing (AM) processes to assess their suitability in the context of upper extremity splinting.

Design/methodology/approach

This paper describes the design characteristics and subsequent fabrication of six different wrist splints using four different AM processes: laser sintering (LS), fused deposition modelling (FDM), stereolithography (SLA) and polyjet material jetting via Objet Connex. The suitability of each process was then compared against competing designs and processes from traditional splinting. The splints were created using a digital design workflow that combined recognised clinical best practice with design for AM principles.

Findings

Research concluded that, based on currently available technology, FDM was considered the least suitable AM process for upper extremity splinting. LS, SLA and material jetting show promise for future applications, but further research and development into AM processes, materials and splint design optimisation is required if the full potential is to be realised.

Originality/value

Unlike previous work that has applied AM processes to replicate traditional splint designs, the splints described are based on a digital design for AM workflow, incorporating novel features and physical properties not previously possible in clinical splinting. The benefits of AM for customised splint fabrication have been summarised. A range of AM processes have also been evaluated for splinting, exposing the limitations of existing technology, demonstrating novel and advantageous design features and opportunities for future research.

Details

Rapid Prototyping Journal, vol. 21 no. 3
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 9 March 2010

Richard Bibb, Dominic Eggbeer and Peter Evans

Maxillofacial prosthetics is faced with increasing patient numbers and cost constraints leading to the need to explore whether computer‐aided techniques can increase…

Abstract

Purpose

Maxillofacial prosthetics is faced with increasing patient numbers and cost constraints leading to the need to explore whether computer‐aided techniques can increase efficiency. This need is addressed through a four‐year research project that identified quality, economic, technological and clinical implications of the application of digital technologies in maxillofacial prosthetics. The purpose of this paper is to address the aspects of this research that related to the application of rapid prototyping (RP).

Design/methodology/approach

An action research approach is taken, utilising multiple case studies to evaluate the current capabilities of digital technologies in the preparation, design and manufacture of maxillofacial prostheses.

Findings

The research indicates where RP has demonstrated potential clinical application and where further technical developments are required. The paper provides a technical specification towards which RP manufacturers can direct developments that would meet the needs of maxillofacial prosthetists.

Originality/value

Whilst research studies have explored digital technologies in maxillofacial prosthetics, they have relied on individual studies applying a single RP technology to one particular aspect of a prosthesis. Consequently, conclusions on the wider implications have not been possible. This research explored the application of digital technologies to every aspect of the design and manufacture of a series of maxillofacial prostheses. Unlike previous research, the cases described here addressed the application of RP to the direct manufacture of substructures, retention components and texture. This research analyses prosthetic requirements to ascertain target technical specifications towards which RP processes should be developed.

Details

Rapid Prototyping Journal, vol. 16 no. 2
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 March 2006

Richard Bibb, Dominic Eggbeer and Robert Williams

The aim of this study was to explore the application of rapid manufacturing (RM) to the production of patient specific, custom‐fitting removable partial denture (RPD…

Abstract

Purpose

The aim of this study was to explore the application of rapid manufacturing (RM) to the production of patient specific, custom‐fitting removable partial denture (RPD) alloy frameworks. RPDs are metal frameworks designed to retain artificial replacement teeth in the oral cavity.

Design/methodology/approach

The study was undertaken by applied case study. An RPD was designed using computer‐aided design software according to well‐established dental technology design principles, based on a digitally scanned cast produced from an impression of the patient's mouth. The RPD design was then exported as an STL file in preparation for direct manufacture using selective laser melting. Dimensionally accurate frameworks were manufactured in 316L stainless steel and chromium‐cobalt alloy. These were assessed for accuracy of fit and function on the patient cast and on the patient in clinic.

Findings

This successful case study demonstrates that an RM approach can produce fully functional, precisely fitting RPD frameworks for specific individual patients.

Research limitations/implications

The study was based on a single design produced using two materials. Further studies are in progress to show that the results can be achieved on a regular and predictable basis.

Practical implications

This study provides some practical guidance for the application described and suggests that similar success may be achieved in related custom‐fitting applications.

Originality/value

The paper demonstrates the successful application of a novel approach to the design and manufacture of custom‐fitting dental devices.

Details

Rapid Prototyping Journal, vol. 12 no. 2
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 17 October 2016

Sandeep W. Dahake, Abhaykumar M. Kuthe, Mahesh B. Mawale and Ashutosh D. Bagde

This paper aims to provide an overview of applications of medical rapid prototyping (MRP)-assisted customized surgical guides (CSGs) and shows the potential of this…

Abstract

Purpose

This paper aims to provide an overview of applications of medical rapid prototyping (MRP)-assisted customized surgical guides (CSGs) and shows the potential of this technology in complex surgeries. This review paper also reports two case studies from open literature where MRP-assisted CSGs have been successfully used in complex surgeries.

Design/methodology/approach

Key publications from the past two decades have been reviewed.

Findings

This study concludes that the use of MRP-assisted CSGs improves the accuracy of surgery. Additionally, MRP-assisted CSGs make the surgery much faster, accurate and cheaper than any other technique. The outcome based on literature review and two case studies strongly suggested that MRP-assisted CSGs might become part of a standard protocol in the medical sector to operate the various complex surgeries, in the near future.

Practical implications

Advanced technologies like radiology, image processing, virtual surgical planning (VSP), computer-aided design (CAD) and MRP made it possible to fabricate the CSGs. MRP-assisted CSGs can easily transfer the VSP into the actual surgery.

Originality/value

This paper is beneficial to study the development and applications of MRP-assisted CSGs in complex surgeries.

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Book part
Publication date: 8 June 2020

Karen Carberry, Jean Gerald Lafleur and Genel Jean-Claude

This chapter explores the impact of delivering culturally community family therapy with strength-based strategies, to transgenerational Black Haitian families living in…

Abstract

This chapter explores the impact of delivering culturally community family therapy with strength-based strategies, to transgenerational Black Haitian families living in Haiti and the Dominican Republic following the 2010 earthquake. A series of workshop intervention over several years, which were co-facilitated by community pastors and leaders provided a cultural-based intervention drawing on Black British and Caribbean culture, Haitian culture, Christian spiritual belief systems, in conjunction with some bi-cultural attachment and systemic methods and techniques. Community feedback through testimonies contributed to evaluation and outcomes in developing new strategies to manage stress, and family conflict and distress, together with developing new strategies in sharing a vision for the future across the community.

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Article
Publication date: 1 February 1986

Amy S. Wharton

Gender divisions are embedded in and essential to the structure of capitalist production. While most men and women in the United States both now work for wages, they…

Abstract

Gender divisions are embedded in and essential to the structure of capitalist production. While most men and women in the United States both now work for wages, they rarely work together. Gender segregation has been identified as one of the major issues of the earnings gap between men and women. An explanation of the forces responsible for this has been difficult to achieve. Most theories fail to consider the contribution of demand‐side factors to gender segregation. Neo‐Marxist analysis of labour market segmentation and theories of the dual economy have provided new frameworks for investigating these structural or demand‐side features of industrial organisation. The pattern of blue‐collar segregation in US manufacturing industries is examined drawing on these theories. Employment data from the US census is used to identify how the levels of blue‐collar segregation in manufacturing industries are influenced by the industry's location within the core or peripheral sector of the US economy. Many of segregation's proposed remedies stress the role of supply‐side factors. These strategies focus attention almost exclusively on male and female workers and ignore the structure of the workplace. Strategies that ignore the dualistic nature of the US economy offer only partial solutions and may be counter‐productive. If forced to eliminate or reduce segmentation, employers may simply restructure their labour processes in a way that undermines rather than contributes to gender inequality. It is apparent that the pursuit of gender equality in the workplace is intrinsically related to and dependent on the broader efforts of workers to achieve greater control over production, both at the workplace and in the economy as a whole.

Details

International Journal of Sociology and Social Policy, vol. 6 no. 2
Type: Research Article
ISSN: 0144-333X

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Article
Publication date: 17 October 2016

John Richard McCardle and Joe Bunyan

This paper aims to investigate whether the trabecular architecture found in natural bone can be effectively replicated through the selective laser sintering process of Nylon P2200.

Abstract

Purpose

This paper aims to investigate whether the trabecular architecture found in natural bone can be effectively replicated through the selective laser sintering process of Nylon P2200.

Design/methodology/approach

Trabecular bone was idealised into a scaled up hexagonal cell proven to replicate the natural structure. The structure was modelled in Solidworks 2013 to form a network of interlinking cells. The specific property analysed was the structure toughness through the measurement of the energy absorbed before sample fracture.

Findings

It was found that the impact absorption can be increased with the integration of a greater number of trabecular cells producing a finer resolution and not necessarily by increasing the trabecular size. The information gained from this research may be useful in the design of impact and shock absorbing components, with an emphasis on efficient use of material mass.

Research limitations/implications

Designers and engineers may find biomimetic methods of absorbing shock and impact an efficient alternative consideration in design applications.

Practical implications

The trabecular architecture should be designed so as to be weaker than the bounding surfaces, ensuring that the individual trabecular experience failure first, maximising their energy absorbing capability through increasing the period of deceleration. The simplest way of doing this is to ensure the rod thickness is less than the bounding material thickness.

Originality/value

This work documents original testing of both the RP material and consolidated design of samples of idealised bone structures. It builds on previous work in the area and through the results of empirical testing, derives recommendations for further considerations in this area of design and manufacture of biomimetic structures.

Details

Rapid Prototyping Journal, vol. 22 no. 6
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 March 1997

Charlie Tyer and Jennifer Willand

Reviewing the development of budgeting in America in the twentieth century, this article assesses where public budgeting is as it approaches the twenty-first century. Five…

Abstract

Reviewing the development of budgeting in America in the twentieth century, this article assesses where public budgeting is as it approaches the twenty-first century. Five periods are identified in American budgeting, drawing upon the work of Schick and Rubin: control, management, planning, prioritization and accountability. Budgeting in the 1990s is described as characterized by accountability and a “new” performance budgeting emphasis. The authors argue that the budget reform movement is still alive and well in American government, with local governments once more leading the way.

Details

Journal of Public Budgeting, Accounting & Financial Management, vol. 9 no. 2
Type: Research Article
ISSN: 1096-3367

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Article
Publication date: 14 June 2011

William Cooke, Rachel Anne Tomlinson, Richard Burguete, Daniel Johns and Gaëlle Vanard

The purpose of this paper is to rigorously determine the tensile properties of a selective laser sintering (SLS) material. Emphasis was placed on the anisotropy and…

Abstract

Purpose

The purpose of this paper is to rigorously determine the tensile properties of a selective laser sintering (SLS) material. Emphasis was placed on the anisotropy and inhomogeneity of the material, the repeatability of the SLS process, and the effect of age (actually moisture absorption) on the material properties.

Design/methodology/approach

Two builds of 144 dogbone tensile specimens each were tested, with 18 specimens stored for 43 days in a non‐desiccated environment before testing. Specimens were distributed throughout the build volume and aligned with the apparatus' principal axes. Tensile properties were treated statistically, using the t‐test to determine the differences between various samples.

Findings

The material was transversely isotropic in Young's modulus and strain to failure, and generally orthotropic in ultimate tensile strength. The material was inhomogeneous throughout the build volume and affected by age, with a 57 per cent reduction in University of Technology after 43 days (the changes in properties were suggested to be due to moisture absorption). Properties varied by up to 25 per cent from build‐to‐build with no change in nominal process parameters.

Research limitations/implications

It was not possible to confirm the “ageing” effect was caused by moisture absorption, and further work is suggested in this area. The causes of inhomogeneity and the effect of re‐coater action should also be studied further.

Originality/value

This is the most complete study of an SLS material's mechanical properties to date. The statistical analyses used further allow increased confidence in the conclusions drawn. This is also the only study to use cross‐fill scanning to produce specimens, and, therefore, isolate the effect of the re‐coater action.

Details

Rapid Prototyping Journal, vol. 17 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

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