Shannon Clark's latest Article on Human Factors and Usability Testing

Human Factors Engineering, an important facet of product development focused on minimizing or eliminating human error through the design of a medical product, is now becoming one of the most critical stages in the design process for medical devices. This is in part due to the FDA’s increased enforcement of Human Factors, as well as the industry’s realization that Human Factors can dramatically affect the success of a medical device.  Shannon Clark, CEO of UserWise, has written an in-depth article on Human Factors and Usability Engineering for Medical Devices that has been published in the recent WSGR Life Sciences Report.

The FDA updated its human factors guidance on February 3, 2016: Guidance for industry and FDA Staff – Applying Human Factors and Usability Engineering to Medical Devices. Manufacturers of higher-risk medical devices began adopting the new human factors engineering processes at the time of the original human factors guidance, in 2011 and even earlier.  Although the need for summative usability testing (a type of design validation) is driven by 21 CFR Part 820.30(g), “Design validation shall ensure that devices conform to defined user needs and intended users and shall include testing of production units under actual or simulated use conditions,” the industry is seeing an increased adoption of human factors engineering processes among medical device manufacturers since 2016.  In part, this increase is due to FDA enforcement of human factors requirements for a medical device; however, there are still companies today that are scrambling to address human factors compliance only after receiving FDA questions around their product submission.

The Human Factors Engineering process consists of 5 basic steps, each of which are more completely described in the full article:

1)   User Research - Design requirements are identified and refined by fully understanding the intended device users and use environments.

2)   Use-Related Risk Analysis – A use-related risk analysis is performed to help predict potential use errors and associated consequences for users as well as patients. Based on the risks, control measures are implemented to make the design as error-proof as possible. And then ultimately use scenarios are formulated for usability testing.

3)   Iterative Prototyping and Usability Testing – Formative usability testing is conducted using early-stage prototypes to identify the strengths, weaknesses, and potential use errors during actual product use. Intended users are observed to see how they interact with the device prototype and subjective feedback may be gathered. This prototyping and testing will continue until the final design of the medical device is complete.

4)   Usability Validation -  At the completion of development, summative usability validation testing is performed to evaluate how the user interacts with the medical device to identify use errors that could result in serious harm to the patient or user. During this testing control measures implemented in the use-related risk analysis are tested to ensure they are sufficient at preventing or substantially reducing use errors.

5)   Human Factors Submission Compliance – For US submissions, a human factors engineering submission report is prepared to describe the entire human factors process and explain how use errors were minimized for the medical device.  For submissions outside the US, a Usability Engineering file is assembled to ensure product compliance with IEC 62366-1:2015, Medical devices – Part 1: Application of usability engineering to medical devices.

Introducing Human Factors Engineering early in the design process allows for usability testing with iterative prototyping, enabling bad designs to fail sooner, rather than later. In the article, Shannon presents a graph on the cost implications of timeliness of introducing human factors and usability testing into the design process. Usability testing will better prepare the medical device  for submission to the FDA, answering any questions the FDA may have regarding safety and efficacy of the device with respect to usability.

For more information on the Human Factors Engineering process, the FDA’s approach to Human Factors of Medical Devices, and how Usability testing can increase the success of a medical device, contact UserWise or read Shannon Clark’s full article in the latest WSGR Life Sciences Report.