Human Factors and Usability Engineering

by Gilero July 8, 2024

A healthy human factors and usability engineering (HFE/UE) process is vital to the success of any medical device development program. HFE/UE ensures the needs, abilities, and safety of users and patients are considered throughout the entire development process. It allows you to make design decisions based on how people will actually interact with your device, rather than expecting users to adjust and accommodate their behaviors to the product.

Basics of Human Factors and Usability Engineering for Medical Devices

Regulatory bodies, such as the FDA, specify a series of activities that should be performed to ensure that your product is safe and effective for use once it hits the market.

1. Research and document all characteristics of the intended users, use environments, and use scenarios.
2. Identify and document all known and foreseeable use-related hazards and hazardous situations.
3. Develop user interface specifications (requirements), particularly those that could prevent misuse and/or harm.
4. Conduct iterative evaluations of the device throughout development, to identify ways to improve its usability and safety.
5. Execute a human factors validation (summative) study to demonstrate that the device is safe for its intended use, the intended users, and the intended use environments.
6. Document the entire process in a final summary reportto support the final submission.

Each step in this process can use a variety of different research, analysis, and testing activities. Some activities, such as Task Analyses, are almost always performed. Others, such as HF Validation studies, are only needed when your device meets a certain risk threshold.

Human Factors Studies and Evaluations

When folks hear “human factors,” the first thing that usually comes to mind is usability testing. This is completely understandable, as usability testing is probably the most visible part of HFE/UE.

At the highest level, studies fall into two categories:

• Formative Studies – Formativesare for learning what you don’t yet know. The purpose of a formative is to identify ways to improve your design – in particular, the design of your user interface, but also its instructions, packaging, and even training. Formatives are for finding out where your design is on the right track, and where it is off track. They give you a controlled, low-stakes way of evaluating the progress of your design.

• HF Validation (or Summative) Studies – HF Validation studies are for confirming what you already know. The purpose of an HF Validation study is to get data that proves that your device is safe and effective for use.

While those two are the most familiar types of HF studies, there are many other kinds of studies as well. These include:

• Contextual Inquiry / Ethnographic Studies / Cognitive Walkthroughs – Generative studies that involve learning about users, use environments, and user workflows. These can be quite valuable as an input to early design efforts.

• Concept Evaluation Studies – Exploratory research that involves presenting intended users with one or more early concepts. This is a good way to get good qualitative data on what users think about your ideas, and how they might imagine it fitting into their workflows. With this information, you can justify choosing a leading concept, or which features of different concepts are ideal.

• Anthropometric studies – Research involving the physical attributes or limitations of your intended users. Literature does not always provide the specific data that you need to make design decisions, so occasionally you may need to generate your own. For instance, if you’re making an injector that’s designed to be used by individuals who have hand deformities, and you’re wondering what the ideal actuation force of the main button should be, you might need to get data on the actual hand dexterity and strength of these users.

• Label Comprehension studies – Studies that specifically evaluate whether end users can locate, interpret, comprehend, and apply the critical information on your labeling and instructions-for-use.

Choose the Right Human Factors Partner

When human lives are at stake, human factors is an invaluable investment. If you ignore human factors, you put your users and patients at risk, and regulatory bodies such as the FDA will not approve your product for market. If you perform human factors but do it poorly, you may end up on the market, but your development costs go up, while investments, sales, and adoption rates go down, putting your business objectives at risk.

At Gilero, human-centered design is a core value. Our in-house team of human factors experts are knowledgeable and experienced in all aspects of medical device usability engineering. Whether your device is simple or complex, or whether you need help with a simple formative study or help with an entire engineering effort, Gilero can help guide you through the process.

For more information about incorporating human factors & usability engineering into your next project, contact us, today!

About the Author

Gilero Gilero specializes in the design, development, and contract manufacturing of medical, drug delivery, and diagnostic devices, bringing innovative healthcare solutions to market. The team combines engineering expertise with a deep understanding of regulatory requirements.