How to Apply Human Factors and Usability Engineering to Medical Devices

Medical devices can be highly advanced, but poor design can make them difficult or unsafe to use. Users may have different levels of training, experience, physical or cognitive abilities, and may operate devices in stressful or unpredictable environments.Human Factors Engineering (HFE) focuses on how people interact with machines, tools, and systems, while Usability Engineering (UE) applies these principles to product design and user interaction.

For medical devices, manufacturers must ensure users can understand information, operate the device correctly, recognize important alerts, and complete critical tasks safely. Poor usability can increase the risk of user errors and harm to patients or operators. Therefore, human factors and usability engineering are essential throughout medical device development. They help identify use-related risks, improve the user interface, and support regulatory expectations, including the principles outlined in IEC 62366-1.

Quick Answer:

Human factors and usability engineering help medical device manufacturers design user interfaces that enable intended users to operate devices safely and effectively while minimizing use-related risks.

What Are Human Factors and Usability Engineering for Medical Devices? #

Human factors and usability engineering are closely linked fields. They consider not only whether a device works, but also how safely and effectively people can use it. FDA describes HFE/ UE for medical devices around three parts: the device user, the user environment, and the user interface. The interaction between these three can determine whether the device is used safely or whether a use error occurs.

In practical terms, human factors medical devices work looks at three connected elements:

• The Device User: What knowledge, skills, physical strengths and limitations might these people have? Consider their abilities and challenges.
• The Use Environment: Where will the device be used? Under what weather lighting and noise conditions will the device operate?
• The Device User Interface: How will the user receive information from the device? How does the user control or interact with the device?

What Is Human Factors Engineering? #

Human Factors Engineering is about understanding what people can and cannot do when they use a device. Human Factors Engineering looks at how people see and understand information, how they handle controls, how they react to alarms, how they remember instructions and how they complete tasks. Human Factors Engineering is not about blaming users when something goes wrong.

What Is Usability Engineering? #

Usability Engineering (UE) applies this understanding to the design and evaluation of the device. Usability Engineering medical devices therefore focuses on whether users can interact with the device in a way that supports safety. IEC 62366-1 describes a process for analyzing, specifying, developing, and evaluating medical device usability as it relates to safety, including risks associated with correct use and use errors during normal use.

How Are Human Factors and Usability Engineering Related? #

The two areas overlap a lot. A simple way to see the connection is:

Human Factors Engineering: Understand the user and the interactions.

Usability Engineering: Apply that understanding to the device and evaluate whether the design supports safe use.

What Is a Medical Device User Interface? #

A medical device user interface refers to the parts of a device that people work with when they are getting ready to use it, when they are using it or when they are taking care of it. These parts can be buttons, screens, warning signals, computer programs, places where cables connect the way the device is wrapped up the labels, on it the directions that come with it and the materials that help people learn how to use it.

Why Is Human Factors Engineering Important for Medical Devices? #

A device can work correctly from a technical standpoint and still create a safety risk if users cannot operate it correctly. Human factors engineering helps manufacturers find problems before they become safety issues keeping people safe.

Reduces Use-Related Risks #

HFE looks at the user, device, and environment together to identify where use-related problems may occur. Design changes can then be used to reduce those risks. FDA identifies as the primary goal of the human factors usability engineering process.

Helps Prevent Use Errors #

A user may select the wrong control, misunderstand information, miss an alarm, or connect a component incorrectly. Just adding instructions or training does not always solve the underlying problem. Often the best solution is to change the design itself, not more instructions or training.

Improves Safe and Effective Device Use #

Clear displays, understandable alarms, logical controls, and appropriate feedback can help users understand what the device is doing and what they need to do next. FDA identifies improved controls and displays, alarm management, safer connections, and better understanding of device operation among the benefits of HFE.

Supports Better User Interface Design #

Human factors in devices play a big role in how controls, displays, alarms, software screens, packaging, labels and instructions are designed. These considerations help make sure that important information is clear and easy to read. They also help make sure that critical tasks can be done safely and correctly by the people who use the devices. The focus is always on making things simple and intuitive, for users.

Reduces Training and Retraining Needs #

A well-designed device should not depend entirely on extensive training to compensate for a confusing interface. Training remains important for many devices, but good usability can reduce unnecessary dependence on manuals and repeated retraining. FDA lists reduced reliance on user manuals and reduced training and retraining as potential benefits.

Helps Reduce Adverse Events and Recalls #

Finding usability problems during development lets manufacturers fix them before the device is used by people. This helps make sure the product works well for everyone. It also saves time and money in the run.

Supports Regulatory Submissions #

Human factors information can also support medical device regulatory submissions. FDA's current approach uses a risk-based framework for determining the human factors information that should be documented and included in marketing submissions.

What Are the Key Elements of Human Factors Engineering? #

Human Factors Engineering focuses on designing medical devices around the needs, abilities, and limitations of their intended users.

Key elements include:

• User Analysis: Understand users, their skills, experience, and limitations.
• Use Environment: Consider where, when, and under what conditions the device will be used.
• User Interface: Design controls, displays, alerts, and instructions for easy understanding.
• Use-Related Risks: Identify potential errors and hazards caused by device interaction.
• Task Analysis: Evaluate critical tasks users must perform to operate the device safely.
• Usability Testing: Test the device with representative users to identify usability problems.
• Risk Management: Reduce or eliminate use-related risks through safer design.

How to Apply Human Factors and Usability Engineering to Medical Devices #

A practical medical device usability engineering process can be approached in eight steps:

1. Define Intended Users, Uses, and Use Environments #

Identify who will use the device, what the users will do with the device and where the users will use the device. Consider factors such as training, experience, physical abilities, sensory abilities and the condition of use.

2. Identify Use-Related Hazards and Risks #

Consider what could go wrong during use. This may include selecting the wrong control, missing an alarm, misunderstanding information, connecting components incorrectly, or performing a task in the wrong sequence. The important point is to correct potential use errors to actual safety risks.

3. Define the User Interface Requirements #

Define what the user interface needs to do to support safe and effective use. This can include requirements for displays, controls, alarms, feedback, connections, labelling, and instructions.

4. Develop the User Interface #

Develop the physical or interface around the intended users, environment, identified risks, and usability requirements. The interface should make important information understandable and critical actions clear.

5. Conduct Formative Evaluations #

Evaluate the developing design with the users while changes can still be made. Formative evaluations can show issues that are not clear to the design team.

6. Refine the Device Based on Findings #

Use the evaluation findings to improve the design. This may involve changing controls, improving displays, modifying alarm presentation, changing task sequences, or revising instructions.

7. Conduct Human Factors Validation #

After the design has been refined, appropriate validation activities are performed to provide evidence that intended users can safely and effectively perform important tasks with the final user interface.

8. Document the Human Factors Engineering Process #

Document the users, environments, risks, user interface requirements, evaluations, design changes, validation activities, and conclusions. This record can also support the regulatory submission.

FDA Human Factors Requirements for Medical Devices #

For manufacturers developing devices for the U.S. market, FDA human factors engineering is an important part of the device development and regulatory process. FDA's guidance recommends appropriate HFE and usability engineering processes to help ensure that devices are safe and effective for their intended users, uses, and environment.

FDA guidance documents generally describe the Agency's recommendations and current thinking; they do not automatically create legally enforceable requirements. The specific human factors information expected for a submission depends on the device and its risks.

FDA's final guidance, Content of Human Factors Information in Medical Devices Marketing Submissions, provides a risk based framework for determining the human factors information to document and include in submissions such as 510(k)s, De Novo requests, PMAs, and HDE applications.

This is why manufacturers should consider applicable FDA usability engineering requirements early rather than trying to prepare human factors documentation only when the submission is due.

How Human Factors Engineering Applies to Different Medical Device #

The specific human factors considerations depend on the device and its intended use. When it comes to devices manufacturers should think about health literacy, physical abilities, sensory abilities and instructions. The user ability to understand and respond to device information is also very important, for patient‑operated devices. For Healthcare Professional operated devices, workload, training, time pressure, alarms, multiple controls, and the clinical environment may be important. For software-based based devices, screen layout, navigation, notifications, data presentation, confirmation steps, and interpretation of information can become important usability considerations.

Human Factors Documentation for Medical Device Regulatory Submissions #

Documentation should show how the manufacturer identified users and use environments, assessed use-related risks, established user-related risks, and established user-interface requirements, evaluated the design, addressed findings, and completed applicable validation activities. FDA's current risk-based approach determines the level of human factors information appropriate for a marketing submission.

Good documentation should allow a reviewer to follow the reasoning behind the final user-related design.

Common Mistakes to Avoid When Applying Human Factors Engineering #

Some common mistakes include treating human factors as a final stage activity, relying on training to compensate for poor design, using non-representative users during evaluations, ignoring the actual use environment, or failing to correct use errors with risk. Another problem is making design changes without considering their effect on the existing usability and risk assessment. Human factors work best when it is part of development from the beginning, rather than something added just before regulatory submission.

How VREG Solutions Can Help With Medical Device Human Factors and Usability Engineering #

V Reg Solutions can help manufacturers with Human Factors and Usability Engineering for devices. We will also prepare the Human Factors documentation and the risk considerations that come from using the evaluations and the submission requirements. A structured approach keeps manufacturers connected to user needs, identified risks, design decisions, usability activities and the evidence that we prepare for submission.

Conclusion #

Human factors engineering is about creating devices that suit the people who use them. Human factors engineering also means that each device must carry out its task properly. It also has to be straightforward and simple to operate. Users need to understand how the device works, interact with it without getting confused and finish their tasks safely. Starting factors and usability engineering early in the development process helps manufacturers spot risks tied to how people will use the device. It leads to an user interface that lets designers test the design, with actual users and helps build solid evidence needed for regulatory approval. This approach is closely linked to risk management. The end result isn't a device that's easier to handle. It's a device built with an understanding of the people, the settings where it will be used and the real tasks involved.

FAQs #

1. Is human factors engineering required for FDA medical device approval? #

It depends on the device and its use-related risks, FDA uses a risk based approach to determine the appropriate human factors information for a submission.

2. How does human factors engineering help reduce medical device use errors? #

It identifies potential use errors and helps manufacturers improve the device design and user interface to reduce use-related risks.

3. What human factors documentation is required for FDA medical device submissions? #

The information needed varies depending on the device. How it's being submitted. It can involve risks related to how the device's used important tasks, reviews, checking and evidence about how people interact with the device.

4. How does human factors engineering connect to ISO 14971 risk management? #

Human factors look at risks that come from how people use the device. ISO 14971 is the framework for managing risks, with medical devices.

5. Can a regulatory consultant help with device human factors and usability engineering? #

Yes a regulatory consultant can help manufacturers interpret the expectations of FDA Human Factors Engineering and Usability Engineering. A regulatory consultant can find gaps, create documents and support regulatory submissions