Human Factors Testing Is the Key to Approval & Profitability in the Medical Device Industry

A look at how human factors engineering and testing can impact regulatory approval, marketability, and revenue.

Heather R. Johnson

June 10, 2024

4 Min Read
Image Credit: 4maksym via iStock/Getty Images

At a Glance

  • Integrating human factors into the full product lifecycle ensures devices are safe and effective.
  • By integrating HFs early into the design process, firms can avoid costly mitigation plans, complaints, and adverse events.
  • If you’re not doing formative work, you’re going to be out of luck with FDA.

U.S. and EU regulators require human factors and usability testing to bring a medical device to market. Virginia Lang, PhD, president and chief scientist at HirLan Inc., an engineering consultancy based in Carlsbad, Ca, said those processes are also critical for profitability.

Integrating human factors into the full product lifecycle ensures devices are safe, effective, and developed in an efficient manner. Those products are then well positioned to reach their intended users sooner and gain an edge over less-intuitive competitors.

“If you’re not doing formative work, you’re going to be out of luck with FDA,” Lang said during the recent Medical Device Playbook presented by StarFish Medical. “You don’t pass or fail a human factors test. You must demonstrate that the use-related risk has been reduced as far as possible and that the device is going to be safe for the intended users, in the intended environment, for the intended purpose.”

Usability vs Human Factors

The terms human factors and usability are not interchangeable, Lang argued. The former relates to human behavior and cognitive processes. The latter relates to the evaluation process of the design.

Human Factors: the application of knowledge about human behavior, abilities, limitations, and other characteristics of medical device users to the design of medical devices. It includes mechanical- and software-driven user interfaces, systems, tasks, user documentation, and user training designed to enhance and demonstrate safe and effective use and enhanced user experience.

Related:You Need Human Factors Folks and Designers: Adventures in Medical Device Usability

Usability: refers to testing that’s incorporated into human factors processes. Usability testing helps device developers and regulators understand how users interact with the device. It also verifies/validates that the device has been designed to reduce use risk as far as possible. It includes both formative and summative testing.

Lang said companies should start human factors work before the design process, beginning with an evaluation of user needs. User needs evaluation includes customer observation and in-depth interviews, among other methods. The goal is to uncover what is and isn’t working to discover problems or “pain points” the customer may or may not know they have.

Only after a user needs assessment and adequate formative testing should medical device developers move into summative testing and reporting. Summative testing is performed on production-equivalent devices and verified software. This is when the device maker verifies/validates the product is ready for submission.

Related:What are the 4 Essential Elements of Medical Device Design?

Examples of questions explored during summative testing include: Is the handle on the correct side of the device? Does it need a handle? Are the instructions on the box, which gets promptly thrown away by a clinician? Is training required? What type? Those that skip earlier formative work will pay the cost in the form of more expensive changes made later in development—or worse, after a rejected FDA submission.

The ROI of Human Factors

To demonstrate the importance of rigorous human factors testing, Lang described a difficult situation a former client experienced. The client hired HirLan to conduct human factors testing on an auto-injector so it could obtain FDA clearance.

Before assembling user groups, Lang tested five of the devices herself. All five broke during use. The client shipped another batch of devices and urged Lang to proceed with user testing. All but a few devices either broke or malfunctioned.

The client had about two million of these devices sitting in a warehouse, presumably unusable. Later, after purported repairs were made, the client requested a new round of testing. The success rate improved, but some devices did fail. In the end, the client spent about $500,000 on human factors testing performed too late in the process. The product never made it into the market.

By integrating human factors early into the design process, medical device companies can avoid costly mitigation plans, complaints, and adverse events. And it’s relatively affordable.

Lang said human factors engineering and testing equates to less than 1% of the total cost of a PMA or 510(k), “if you do it at the right time, using the right resources,” she said.

As a ballpark, formative methods and testing range from $15,000 to $30,000 for an expert review to $62,000 to $120,000 for formative testing. Summative methods and testing hover in the low six figures. Training raises those costs by about 40%. Time frames range from one week for a needs analysis to about six weeks for formative testing.

Lang noted that staged product lifecycles were designed to streamline the complicated path from medical device concept to regulatory submission. Human factors is a component best not left until later.

“If you don't use your time wisely with human factors, you're going to be spending a lot of money, and not just for human factors but for everything else,” Lang said.

About the Author(s)

Heather R. Johnson

Heather R. Johnson is a consultant and writer for the medical and clinical technology industries. She’s based in the San Francisco Bay Area.

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