Mark Turner: Medical Engineering Technologies (MET) has been supporting medical device developers for over 20 years. At MET, we understand a wide range of devices, and have team members that have worked as research and development project managers. Hence, we can rapidly assimilate a client's needs and propose a robust design validation test programme.
Progress involves a risk analysis of the device's design and purpose, a gap analysis of what data is available and a review of performance standards. We then use this information to develop the test programme - design inputs and outputs. The data that's gathered gives the client confidence to move forward to full production and marketing of their device
Our quality management systems, and detailed protocols and reports, mean auditors will be comfortable that the evidence for safety and performance is comprehensive and clear. Because we cover many aspects of testing within our facilities, and work almost entirely with medical or combination devices, our programmes are efficient and comprehensive.
Our newest addition is electromagnetic compatibility testing. This safety testing is used to ensure that the electronics in a biomarker point-of-care diagnostic for a stroke does not interfere with, for instance, a pacemaker operating for a patient in the next bed, while also showing that the IVD is immune to signals coming from the pacemaker.
Two growing areas are the application of chemical testing to biological safety evaluation and, similarly, the new toxicity tests for breathing components detailed in ISO 18562.
The changes in biological evaluation are nothing short of revolutionary. The FDA has now recognised the fifth edition of ISO 10993 - the 2018 version. This means that animal testing is now a last resort and chemical evaluation is de rigueur for toxicity testing.
The new version of the standard requires a chemical and material understanding of the device, and knowledge of how those materials interact with the end user. This does not make chemical analysis obligatory, but, because unexpected materials can creep into a product in production and knowledge of intended input materials may be incomplete, it is likely that some chemical investigation is required.
MET has developed a system of levels of intensity of interrogation based on the ISO 10993 biocompatibility matrix. That is to say the depth of extractables and leachables analysis is based on patient contact invasiveness and time. The chemical information then requires assessment in a toxicological risk analysis, which becomes the regulatory submission. There are still some areas that are difficult to examine using this route, such as local effects of implantation and haemocompatibility.
A project starts out with a great idea - some improvement in diagnosis or treatment. The most enjoyable part of the project is developing ideas, making prototypes, getting opinions on designs; but as time progresses, consideration must be given to production processes and volumes.
The engineer now has the design inputs and means to produce, but they still need the design outputs and regulatory processes. So my advice is that design validation is at the end of your project, so plan for it. Although MET is very knowledgeable and efficient, studies require a finite time to complete and results are not always perfect. Some testing can be conducted earlier in the project. Risk analysis for the development process will have ensured that early testing results from the examination of materials, features and processes will give a high degree of confidence in success. You should get your validation partner involved early and involve them in your risk analyses.
