By David Orenstein, Product Development Engineer (EG-GILERO)
Nowadays it is becoming more and more apparent that the FDA wants validated data demonstrating that the intended user can use a medical device safely and effectively. The FDA has four expectations of Device Design regarding usability1:
- “Conduct a comprehensive risk assessment”
- “Identify and mitigate risk, including all use related risks”
- “Conduct human factors/usability validation testing on any strategies implemented to mitigate significant use-related risks”
- “Document everything in the Design History File”
As an engineer it is easy to forget that the users may not possess the insight or skills an engineer has to quickly pick up a product and understand its function(s). Users of medical devices, such as certified nursing assistants, paramedics, and licensed nurse practitioners, may be very intelligent but depending on their experience, they may not have a background that helps them readily adapt to new technology.
There is also another element to consider here – the fact these people are human. Humans are prone to making all sorts of mistakes; and if most people are anything like me they love to skip reading instructions. It is for this reason that devices need to be as intuitive and simple as possible from the user’s perspective. Our users are likely to be dealing with highly stressful situations and even more advanced users such as registered nurses or physicians may get nervous when using a new piece of technology on a patient if mistakes can lead to permanent injury or death.
So what is the point? The point is take advantage of formative studies and be prepared for your validation study or the FDA may hit the pause button and send you down an expensive path that may be difficult to recover from. I am not going to pretend $30,000 is a small sum, especially when validation (summative) studies cost another $70,000-$100,000+. But I have been there when users are struggling to understand your device during a validation study and are failing to do so safely and effectively. It is not a pleasant feeling when viewing in real-time from the other side of the mirror; and remember, you cannot yell at the user. It is not their fault.
This is why I highly recommend performing formative user studies with real users to get feedback on your device in the more primitive stages of design. The engineer sitting next to you has a completely different perspective when evaluating a device than the man or woman whose job it is to save your life. The FDA wants to know that your device is both safe and effective. Do you have the data to back that up?
 Molly Follete Story, PhD. “FDA Perspectives on Human Factors in Device Development.” U.S. Food and Drug Administration. June 07, 2012. https://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/HumanFactors/UCM320905.pdf (accessed June 08, 2018).