Findings
Human Factors Engineering (HFE) and Usability Engineering (UE) are fundamental for medical device safety and effectiveness. The HFE/UE process focuses on the interactions between people and devices, considering three major components: device users, device use environments, and the device user interface. The most important goal of this process is to minimize use-related hazards and risks. The FDA’s HFE requirements are derived from the Quality System Regulation (QSR), specifically relating to Design Input (needs of the user and patient) and Design Validation (conformance to defined user needs). If risk analysis shows that use errors could lead to serious harm, HFE is explicitly required and must be submitted in premarket submissions (PMA, 510(k)).

Recommendations
Manufacturers should follow HFE/UE processes throughout the device development to improve design and minimize potential use errors. This involves an iterative process that runs parallel to product development. Key steps include:
User Research: Understand the intended users (e.g., professionals, patients, lay caregivers) and their characteristics (e.g., physical, cognitive abilities, experience).
Risk Analysis: Focus on potential use errors and identify critical tasks where errors could result in serious harm.
Formative Evaluation: Conduct evaluations during development to generate ideas for test scenarios, identify dangers early, and gather input for user interface improvements.
Design for Safety: Apply the hierarchy of risk control, prioritizing inherently safe design and protective measures (alarms, warnings) over instructions and training.
Usability Validation Testing: Conduct final summative testing with representative users under simulated real-world use conditions to demonstrate the device can be used safely and effectively.

Regulatory Considerations
The FDA recommends that manufacturers submit human factors data in premarket submissions for devices where risk analysis indicates that use errors could result in serious harm. The FDA has provided guidance on the content that should be included in these submissions, such as descriptions of intended users, use environments, user interface, risk analysis of use-related hazards, and results of validation studies. Manufacturers should also continue to monitor user interactions through postmarket surveillance and adverse event reporting.