Design rationale for the regulatory approval of medical devices

Design rationale is a methodology aimed at capturing and representing design decisions according to a designated structure. Additionally, these design decisions and their underlying arguments can be made available for examination at a later date. The literature review identified that there is currently a lack of information describing the use of design rationale methods and computational support tools with the medical device domain. Furthermore, the review of literature has also recognised that there are no existing guidelines available for medical device manufacturers and regulatory authorities to follow in order to capture and represent the design decisions in the case of medical devices. Medical devices are instruments which are used for diagnosis, screening, monitoring, or the treating of patients suffering from disease, injury, or disability. Medical devices are products that require rigorous regulation before they can be placed onto the market. If problems are encountered with a device once it has been placed onto the market, the device is recalled by the relevant regulatory authority. Device recalls can often result in the device manufacturers having to evaluate the design decisions that were made during the product development stages in order to address the reported problems and implement a solution. As a result, medical device manufacturers can incur unexpected rework and/or redesign costs, and in even more severe circumstances, incur high litigation costs. This research; reviews the state-of-the-art in design rationale and identifies its key capabilities, analyses design rationale’s feasibility for use with the medical device domain, identifies the regulatory approval processes for medical devices and compares them, analyses the possibilities of utilising design rationale with the regulatory approval of medical devices, and develops a set of guidelines. The guidelines detail the necessary steps that are required to capture and represent the design decisions for medical devices. The utility of this contribution has been verified through the process of validation with experts and researchers.Engineering and Physical Sciences Research Counci

Developing Microelectromechanical Systems (MEMS)

Intellectually and technologically, the art of design is one of the oldest forms of mankind’s expression of creativity. Since the early days of primitive man to now, humans have discovered needs that require functional artefacts to perform necessary operations. There are vast differences in the appearance and applications of such artefacts which have varied with time. Developing artefacts to fulfil the new and changing requirements presents a creative response to problem solving at the macro and micro scales. Developments in technology have progressed rapidly driven by the requirement to create smaller artefacts that possess a larger variety of functions. The current developments of micro and nano scale devices have the potential of triggering a technological revolution in many fields. The healthcare industry is utilising micro and nanotechnology applications and aiming these to provide quicker and more affordable medical diagnostic equipment such as the lab on a chip. This is currently being developed to provide a point of care testing to analyse blood samples for different viruses, in a miniature blood testing laboratory which is in the space of a microchip, and providing the appropriate response in a real time environment. Some of these devices are still in the conceptual phases with the possibility for future large volume manufacturing however; the development of microelectromechanical systems or MEMS as they are more commonly known, is performed by the experts with an intuitive based approach. In such context, this thesis proposes a theoretical model for the development of MEMS devices by examination of literature in; generic product development processes used in the engineering and manufacturing areas and capturing how MEMS are currently developed. Parallel to this, development practices currently deployed for MEMS as performed by the experts and practitioners have been illustrated in the form of an As-Is model validated by MEMS experts. The use of IDEF0 to model the existing MEMS development process has provided the necessary tool to analyse the existing process, recognise the limitations, identify the areas of improvement and implement these into a To-Be model proposed for future MEMS development validated by domain experts

A descriptive model of the current microelectromechanical systems (MEMS) development process

This paper uses the IDEFØ process modelling technique to present an ‘As-Is' model for the current process of developing generic MEMS devices, this new model is based on information from current practitioners. The model shows a seven- stage process, from customer requirement specification to testing and verification, with multiple iterative loops between several stages of the model. Process-constraints on current MEMS development are also reported in the paper. A comparison was attempted between this As-Is model and the candidate models for future MEMS development available in literature. Differences include the number and placement of process iteration stages and the quantity and type of the development activities. Further comparison is difficult, partly because of the different approaches, taken to represent MEMS development stages and development flows, used by different auth