In the medical device world, Usability Engineering (IEC 62366 – The application of Usability Engineering or its 60601 counterpart IEC 60601-1-6) is a required tool within the validation of a medical device. Regardless of whether it’s software, active, or IDV, Usability Engineering helps us understand how the device (or system) performs in real-world applications.
Risk Assessment and Usability
Usability Engineering draws from the risk principles outlined in ISO 14971 and identifies hazardous situations that users may encounter while using the device. However, it encompasses much more than just risk identification.
Understanding Key Concepts
Many organizations struggle with the concepts of “hazard-related use scenario” and “hazards.” Let’s clarify these with practical examples:
- The risk assessment process follows standard medical device protocols
- Special attention to EN ISO 14971 vs. ISO 14971 for EEA markets
Practical Example: Smoke Alarm System
Technical Controls
Consider a typical smoke alarm:
- A system failure might be an insufficiently loud siren
- ISO 12239 specifies compliant fire system development
- Controls involve designing to these requirements and verification testing
Usability Engineering Focus
Usability examines the human-device interface, which can include:
- Sounds (buzzers, beeps)
- Visual indicators (lights, text, symbols)
- Tactile feedback
- Training materials
We test by placing users in controlled hazardous scenarios to evaluate their response.
Implementing Effective Controls
Example Hazardous Scenario
Situation: User doesn’t understand the alarm meaning and fails to act
Potential Controls:
- Training materials
- Reference documentation
- Clear visual indicators
Note: We exclude “unforeseeable abnormal use” (malicious intent) from consideration, focusing only on normal and foreseeable abnormal use conditions.
Proper Verification Methods
Avoid simply checking if controls exist – this only confirms implementation, not effectiveness.
Effective Verification Process:
- Provide training and materials to users
- Simulate alarm activation
- Observe user responses
Measure success by evaluating how identifiable, understandable, and usable the controls were in preventing the hazardous situation.
Why Usability Engineering Matters
This simplified example demonstrates how usability engineering applies to medical devices. Effective usability studies provide critical feedback for device development and improvement.
Our medical device consultants have extensive experience implementing usability studies for various medical and non-medical devices.
Contact us to learn why we’re the ideal partner for your usability engineering and medical device consultancy needs.
