The lifecycles of many medical devices are extremely complex, as is their design process, which requires a great investment in time and expert procedures at all stages. This article highlights the critical issues to consider when embarking on a design project and how to reduce the risks involved in long life cycles.
The pitfalls to avoid
Medical device design is as much about managing risk and overcoming challenges as it is about producing a safe and effective product. The obstacles faced by medical device manufacturers during a product’s lifecycle include the requirement for continual improvement and feedback systems, technology changes, obsolescence of components, environmental constraints, material reliability, documentation and certification. For some manufacturers such as those producing high cost capital equipment, product lifecycles must be supported for five to ten years. Thus good design is paramount to reducing the risk associated with long complex lifecycles.
Where it starts
The starting point for a design project is often selecting a design consultancy with the correct approvals for the design of medical devices. Choosing consultancies that are unable to provide the proper level of medical design certifications or documentary evidence that their products have been designed to the correct standards presents problems. They have led to manufacturers having no option but to redesign their product from scratch using the correct design channels, which is costly and time consuming.
Manufacturers are frequently misguided by design consultancies that claim to be medical product designers, but in reality deal only with health care and lifestyle health products such as activity monitors or sports aid devices. Products like these do not come under the stringent regulatory control that medical devices require. Design consultancies that handle only “health care” products will simply not have the correct approvals for developing medical devices. This means they may not provide the right level of compliance with standards or the necessary documentation for medical products to be certified. Manufacturers should seek a design consultancy certified to at least ISO 13485:2003, Medical Devices, Quality Management Systems, Requirements for Regulatory Purposes, and ISO 9001:2008, Quality Management Systems Requirements.
Manufacturers should also understand what capabilities the design consultancy has for risk assessment, failure mode and effect analysis (FMEA) and quality management reviews. It is important to check that the designer is experienced at maintaining documentation, because this will be crucial later on for product approvals. Tables I and II provide a checklist of points to consider when choosing a design consultancy.
The medical device lifecycle can be divided into three main design stages. The first phase is predesign, which primarily focuses on the research and development of theories, ideas and requirements specifications. This calls for results to be tested through data collection and analysis, which are then assessed for product feasibility. This phase can last from a few weeks to many years depending on the complexity of the technology being studied.
The design team also needs to be familiar with competitive products in the market place and a programme of market research should be under- taken to understand how the developing technology or product could be positioned and used. This also provides information for early sketches and specifications to be made. On the technological side, the designers will need to explore possible barriers to developing the technology. For example, the patents may restrict certain technical approaches and this may require new solutions to be developed. The technology must also be considered in terms of cost: some products may require simple solutions, while others demand the latest technological input.
Often manufacturers have an early “proof of principle” prototype at this stage in the design process. These prototypes need to be assessed through a comprehensive design audit to determine whether the early design work is suitable for further development and how it can be improved. For product improvement, brainstorming techniques are often invaluable for generating new ideas. Once a technology has been validated through the predesign process, it is important that intellectual property is secured for the customer and protected for the future.
The mid-design phase examines all elements of design (mechanical, industrial, system architecture, electronic and software) through to development, prototyping and commercialisation of the product. The product also undergoes thorough scrutiny to meet all regulatory demands.
For medical devices, this phase focuses on evaluating the risks of the design. This involves defining the scope of the product, identifying all potential hazards, assessing all components and designing to minimise the risks of potential failure. Any software associated with the product is also considered a critical component and this can drastically affect the overall quality of the device if it is not designed using formal rules to ensure it complies with EN/ISO 62304, Medical Device Software, Software Life Cycle Processes. Each element of the design must be analysed and clear documentation provided for assessment by regulatory bodies. This is a crucial part of the product development process and can be a major pitfall for start-up companies that are unfamiliar with the demands of medical device design. New enterprises are likely to need support in setting up a quality system for the formal validation and verification process. There are several design consultancies that provide a service to set up companies’ quality processes and procedures. This can be developed to a level that allows the company to register its quality system to ISO 13485.
Once the device design is prototyped, verified and validated, it is time to start production, but once again there are regulations to follow in the manufacturing and testing process.
The post design phase covers the commercial part of the lifecycle. This stage is concerned with taking the product to market and evaluating market feedback to help drive the development of the next-generation product when the cycle starts anew. Manufacturers should demonstrate a process for collating feedback from users and their service personnel to define improvements to the product. This “continual improvement” should be demonstrated and recorded.
Less engineering work is necessary than in the mid-design phase, but the process of continual improvement could lead to the product having new features added, which in turn requires retesting and further approvals before the product can be released to the market.
Other important aspects of this phase include decisions about maintenance and repair, for example, whether components are still available and weighing up the cost of maintenance and repair against redevelopment. End of life issues are also important, because manufacturers are responsible for the disposal of products under directives such as the Waste Electrical and Electronic Equipment Directive (WEEE). Designers must therefore make products as simple as possible to dismantle and dispose of, or recycle, at the end of their life. The disposal route should also be defined and documented as an end of life procedure. This procedure will also define what constitutes the end of life of the product, which is not always a simple process for expensive devices that can be repaired or serviced for many years.
The future of medical device design
There are several important issues that are likely to shape the future of medical product design. Environ-mental legislation is already in force to restrict certain materials and encourage greater recycling. This has affected component sourcing and although some medical products are exempt from the legislation they are effectively bound to it by default. It is likely that there will be a greater uptake of bioderivative materials rather than plastics, because these materials have less of an environmental impact during manufacture and are easier to dispose of at the end of their life.
With a growing emphasis on environmental performance, sustainable design approaches are rapidly being implemented. Sustainable design looks at ways of reducing products’ carbon footprints during their life-cycle. This includes reducing the energy (and thus carbon dioxide) required to produce materials, reducing the energy used for manufacturing, minimising energy during product usage and finally during disposal.
The combination of innovative materials and advancements in other areas of technology such as electronics and sensors offers enormous potential for the future of medical product design. By harnessing the research of academia and industry, new methods and techniques will be developed that ultimately result in new devices that bring a better quality of life to the user.
Although the lifecycles of medical devices can be long and complex, in the hands of the right design partner, product development can be streamlined to reduce development times and costs, whilst still retaining quality, innovation and managing issues for the future.
Steve Lane is Commercial Director at Triteq Ltd, which specialises in electronic design and production services, 3 The Courtyard, Stype Hungerford RG17 0RE, UK, tel. +44 1488 684 554, e-mail: firstname.lastname@example.org www.triteq.com
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