Ludrick Barnard

Using RP to promote collaborative design of customised medical implants

Purpose – The last decade has seen major advances in rapid prototyping (RP), with it becoming a multi‐disciplinary technology, crossing various research fields, and connecting continents. Process and material advancements open up new applications and manufacturing (through RP) is serving non‐traditional industries. RP technology is used to support rapid product development (RPD). The purpose of this paper is to describe how the Integrated Product Development research group of the Central University of Technology, Free State, South Africa is applying various CAD/CAM/RP technologies to support a medical team from the Grootte Schuur and Vincent Palotti hospitals in Cape Town, to save limbs – as a last resort at a stage where conventional medical techniques or practices may not apply any longer.Design/methodology/approach – The paper uses action research to justify the proposal of a new method to use CAD/CAM/RP related technologies to substitute lost/damaged bone regions through the use of CT to CAD to.STL ma...

Stereolithography build time estimation based on volumetric calculations

Purpose – Not all the inventors and designers have access to computer‐aided design (CAD) software to transform their design or invention into a 3D solid model. Therefore, they cannot submit an STL file to a rapid prototyping (RP) service bureau for a quotation but perhaps only a 2D sketch or drawing. This paper proposes an alternative approach to build time estimation that will enable cost quotations to be issued before 3D CAD has been used.Design/methodology/approach – The study presents a method of calculating build time estimations within a target error limit of 10 per cent of the actual build time of a prototype. This is achieved by using basic volumetric shapes, such as cylinders and cones, added together to represent the model in the 2D sketch. By using this information the build time of the product is then calculated with the aid of models created in a mathematical solving software package.Findings – The development of the build time estimator and its application to several build platforms are desc...

Rapid manufacturing of patient‐specific shielding masks, using RP in parallel with metal spraying

Purpose – The purpose of the present work is to develop a methodology to manufacture patient‐specific models (lead masks) to be used as protective shields during cancer treatment, using 3D photography, rapid prototyping (RP) and metal spraying. It is also intended to reduce the trauma experienced by the patient, by removing any physical contact as with conventional methods, and also to reduce the manufacturing lead time.Design/methodology/approach – Patient‐specific data are collected using 3D photography. The data are converted to.STL files, and then prepared for building with an LS 380 in nylon polyamide. Next, the sculpted model is used as the mould in a newly patented metal‐spraying device, spraying liquid metal on to the sculpted surface.Findings – Intricate body geometries can be reproduced to effectively create metal shields, to be used in radiography applications. The models created fit the patients more accurately than through conventional methods, reducing the trauma experienced by the patient, ...

Anaesthetic mouthpiece development through QFD and customer interaction with functional prototypes

– The paper reflects on the development of a medical product using rapid prototyping technologies and customer interaction through a quality function deployment (QFD) approach to speed up the process, and to result in customer satisfaction. The purpose of the specific medical product was to develop a device for fixing an Endo‐tracheal (ET) tube in a patient during anaesthesia, as it is common for an ET tube to move and/or become dislodged due to various extraneous reasons. If the tube deviates from the correct position it can cause one or both lungs to collapse, which can be fatal. The paper reviews how the anaesthetists idea, which was to develop a product that could hold an ET tube in place in a more secure manner than is possible with current technologies, was brought to fruition through customer interaction., – Using an action‐research approach, the design evolved through series of design concepts, which through customer interaction contributed to a total optimized design. Virtual and physical prototypes, together with silicone mouldings were used as part of the customer interaction., – As with any new product, some functional parts were needed to conduct tests, which in turn would help to prove the product, and hence, the design. Traditionally this meant the manufacturing of a hard tool and proving of the design through trial and error. Hard tooling allows for some small changes to be made, but if the changes are radical a new tool will have to be designed and manufactured., – Following a developmental approach through the application of various types/stages of prototyping (such as virtual prototypes), revolutionised this process by simplifying and accelerating the development iteration process – it also developed a new version/paradigm of QFD., – Opposed to traditional forms of QFD where customer inputs are gathered through questionnaires, this case study proved that functional models provide an efficient client‐feedback, through constant involvement in the development process, as well as evaluation of the systematic progress., – The case study shows that experts in other disciplines can become involved in the product development process through the availability of functional prototypes, and builds on previous work to introduce a concept of customer interaction with functional prototypes.

Rapid tooling in support of accelerated new product development

Purpose – The paper examines whether additive manufacturing can deliver durable injection‐moulding tools – fast, reliable, accurate and economic. Researchers from the Central University of Technology, Free State (CUT), South Africa, are involved in rapid prototyping (RP) applications‐based research, simultaneously using results to support small‐ and medium‐sized enterprises (SMEs) on a national basis – both with contract research and technology transfer[1]. SMEs in South Africa involved in product development, are often hampered by economies of scale. Many new products simply disappear in the product development valley of death, partly due to manufacturing costs and limited product development budgets. RP has been used extensively by Technimark, one of the CUTs industrial partners, to evaluate and verify designs in various design stages. To remain competitive in the global market, Technimark and the CUT often have to apply RP directly as the manufacturing method. The paper discusses the use of RP to supp...