IDC projects director, Brian Gough, delivered a key presentation at this year’s Plastics in Medical Devices (Brussels, May 2009), suggesting that the design opportunities offered by plastics are almost infinite - providing you ask the right questions from the outset.
The presentation highlighted a range of factors affecting plastics choice in design when developing a world class medical device. Addressing the essential issues of device application and risk classification, as well as regulation, testing and compliance, Gough drew on several award-winning medical products designed by IDC to illustrate how to tackle the central points in the process.
IDC’s multi-award winning insulin pen designed for Indian healthcare giant Wockhardt, provided a strong insight into the process. With diabetes a significant problem in India, Wockhardt was able to supply insulin but lacked a cost effective way to administer it. The company needed both a disposable and reusable injector pen each made from 100% plastic, which would meet stringent international regulations (ISO/FDA), testing and compliance, and also side-step existing patents without compromising on quality.
“As with all medical device projects, understanding a product’s purpose and function, and identifying competing products in the marketplace is vital. What sort of weight and strength is required for durability? Are there specific or unusual aspects of mechanical performance to be met? Will it need to be resistant to oils, UV, solvents, radiation? The question of the device’s classification is the next issue, raising questions over sterility and additional concerns from cleanliness in manufacture to infection control and bacterial barrier properties, depending on how and where the devise is used. All these factors, as well as tooling and manufacture, affect polymer choice for the designer,” said Gough.
Before embarking on the insulin pen design, IDC examined the market and user needs, isolating and analysing competitor products and their regulatory requirements. Engineers and designers reviewed over 150 patents, 30 competitor products and their functional mechanisms, as well as the requirements of international standards. They also conducted user interviews and discussed the product with GPs.
IDC’s in-house Viper SLA machine provided a prototype for verification and accuracy, which could then be taken to TNO for initial opinion and guidance to obtain a medical CE mark. In total, 15 plastics were used, each carefully selected on the basis of mechanical, chemical, aesthetic and functional properties, as well as cost.
Gough continues, “The application and level of invasiveness of any given medical device will naturally affect the polymer choice, verification and manufacture process – and the overall cost. But it’s important to remember that just because a device is medical, doesn’t mean it necessarily needs a medical grade material.”
Other IDC case studies discussed which use plastics in medical design included:
- The world’s first non-invasive Medick Personal Heart Monitor from concept to production (class 1) developed and launched within 6 months
- The ZYDUS CADILA Asthma Inhaler (class 2a). Millions sold across India
- The Vielle Stimulator for women with sexual dysfunction. Awarded The Design Effectiveness Award for consumer product (class 1)
- The Venner LoTrach™ Cuff Pressure Controller (CPC) for monitoring and controlling the inflation pressure of LMA LoTrach™ Endotracheal and Tracheostomy tubes (class 2a)
In conclusion, Gough explained, “One thing is absolute: the use of plastics in today’s medical devices opens many doors in terms of design, but it is only through an accurate and in-depth understanding of polymers in the context of medical classification and the corresponding regulations that superior quality products can be designed.”
