How to Design a Simulated-Use Environment for a Medical Device Usability Study
At Rebus, we’ve supported usability testing in environments ranging from home use to neonatal intensive care units and ambulances. One of the most common questions we get from our clients is: How realistic does the simulated-use environment need to be? And more importantly: what do regulators expect?
Here’s a practical guide to help you navigate the requirements and design a simulated-use environment that’s fit for purpose in your next human factors study.
What is an intended-use environment?
Your intended-use environment is the real-world setting where your medical device will be used. It’s defined early in development and documented in your Use Specification. This includes:
- Physical conditions – gloves, personal protective equipment (PPE), clothing
- Lighting – from dim to bright
- Noise – ambient or intermittent
- Personnel and team dynamics – supporting surgeons, nurses, theatre staff, patients
- Equipment and furnishings – neonatal incubator, monitoring equipment
- Climate – temperature, humidity
- Distractions – alarms, interruptions
These factors can influence how users interact with your device. That’s why they need to be considered as part of your usability engineering process.
What is a simulated-use environment?
A simulated-use environment is a mock-up of the real-world setting. It’s used during usability testing to recreate realistic use scenarios. This helps you observe how users interact with your device and identify any use-related risks.
According to FDA guidance and IEC 62366-1, simulated-use testing is important when validating that a device can be used safely and effectively by its intended users, in its intended environments.
Why does it matter?
A well-designed simulated-use environment helps:
- Reveal environmental factors that could impact device use
- Encourage naturalistic behaviour from participants
- Support regulatory submissions by demonstrating realism
For example, using a manikin or actor can help participants immerse themselves in the scenario, leading to more representative interactions.
Do I need a simulated-use environment?
If your device has critical tasks – where use error could cause serious harm – you will usually need a simulated-use environment for human factors validation testing (also known as summative usability testing).
For combination products, FDA’s 2023 guidance goes further, requiring consideration of any harm when defining critical tasks. IEC 62366-1 also expects you to justify how your test environment represents the intended-use environment.
How realistic does a simulated- use environment need to be?
The level of realism should reflect:
- Relevance to critical tasks
- Likelihood of impact on correct use
- Context required for avoidance of potential use errors (e.g. triggering a sense of urgency)
You don’t always need a full simulation suite. Often, a well-equipped conference room with key furnishings, PPE and lighting adjustments can be enough.
A useful approach is to include a table in your protocol comparing the intended-use environment with the simulated-use setup, with space to justify any differences:
| Characteristic | Intended- Use Environment | Simulated- Use Environment | Justification |
| Lighting | Low to bright (25-1000 lux) | Office- style lighting | Alternative light sources likely available in real use if lighting is too dim |
| Equipment | ECG monitor, oxygen tank | None presented | Critical tasks unrelated to peripheral equipment |
| Physical Environment | Gloves and mask used | Gloves and mask available for participants | Matched simulated and intended use environment characteristic |
This helps demonstrate to regulators that your simulation is appropriately representative.
Final Thoughts
Designing a simulated-use environment isn’t just about ticking a box – it’s about creating conditions that allow you to uncover real use-related risks. Whether you’re testing in a hospital mock-up or a conference room, the key is to ensure your setup reflects the realities of use.
During the fitout of our viewing facility in Bristol last year, we created a highly flexible space that can be quickly configured to provide a simulated-use environment for a wide range of projects. Investing in high fidelity props and paying attention to environmental attributes that provide meaningful context can help to elevate participant engagement and reduce rates of dreaded study artefacts. All this serves to provide regulators with the necessary assurances that the study environment has been given due consideration and integrated into the human factors engineering process.
Rebus has a proven track record supporting clients with intended use environment specifications, protocol design and study delivery. For pragmatic, risk-based advice on your next project, please get in touch.