When it comes to simulated use environments, how realistic is realistic enough?
Aug 6, 2025
Author: Haroula Tzamaras, Human Factors Consultant
When it comes to medical devices and usability testing, it is a known requirement that production equivalent devices must be used for validation testing. For formative testing, however, the fidelity of the device depends more on the question being asked. In this context, fidelity is defined as how closely the prototype matches the final intended design (1). While design discussions generally focus on the fidelity of the device itself, another important point is the fidelity of the use environment in which the study is conducted.
Simulated Use
Human factors usability studies are typically conducted in simulated environments, whether they are meant to be used at home, in an operating suite, a reprocessing room, etc. When considering the creation of a simulated space, one key factor is fidelity. Simulation fidelity, in this case, refers to the degree that the simulated environment represents a real-life scenario. A high-fidelity simulation would be the most realistic, for example, testing a surgical device in an actual operating room; however, a low-fidelity simulation might involve testing the same device in a basic office setting.
Another aspect to consider for simulation fidelity is the personnel who will be conducting the usability test. A common debate in the human factors community is whether team members, such as moderators and observers, should wear scrubs when testing in a simulated operating room, to match what would typically be worn by medical staff in that space. Should the facilitator be dressed similarly? Would this enhance the realism of the experience for the participant?
Many human factors practitioners believe that the study team wearing scrubs when in an operating room or other type of clinical environment does create a more realistic experience for the participant. Often, healthcare professional participants arrive in scrubs themselves, which helps further immerse them in the simulation.
The best way to ensure success with simulated use testing is to do extensive research on the device being tested to best understand the environment in which it would be used and how to maximize the fidelity of the space. For example, if a device is intended for use in surgery, understanding where the device may be set up in the surgical environment, what instruments would be around it, and how it might be transported by surgical staff around the space would allow the environment to be set up as accurately as possible for the user. Or if the device is intended to be used on the go and potentially in stressful or emergency situations, such as an inhaler or EpiPen, testing it in a regular simulated living room might not be close enough to reality to accurately capture potential user errors. Simulating a more public space with background noise, for example, could help make the experience more realistic.
When determining the level of fidelity needed for your simulated use test, here are a few factors to consider:
Validation or formative testing
Comfort level of the participants
Stage in the design process
Time constraints
Cost constraints
Should formative tests and validation tests have different levels of simulated use fidelity?
It depends specifically on the question being asked and the nature of the test. The 2016 FDA guidance specifies that the conditions for simulated use validation testing should be “sufficiently realistic so that the results of the testing are generalizable to actual use” (2), and that the realism should be dependent on the risks associated with each potential use error. For formative testing, the guidance focuses more on the types of evaluations than the testing environment.
Because formative testing is generally conducted earlier in the product development cycle, it often addresses more general questions or focuses on a specific aspect of a device rather than validating the overall usability of a device. For example, a formative study aimed at gathering subjective feedback on a single device feature may not require a fully immersive, realistic environment, or even a production equivalent product. On the other hand, a formative study focused on understanding if participants can read and follow instructions before moving to the validation stage would be better suited to take place in a more realistic environment with proper lighting and noise conditions.
Low-fidelity environments can lead to an increase in the number of study artifacts, or use errors that are caused by the simulated use environment or scenario, which undermine the validity of the study. Therefore, for validation testing, the more realistic the simulated use environment, the more accurate the results.
Bottom Line
The results from simulated use testing are only going to be as real as the environment they were tested in. A product intended to be used in a bright, busy surgical suite, but tested in a quiet, dark room by participants in casual clothing, may not trigger the same cognitive load or emotional strain to uncover all the potential use errors or safety issues. More realistic simulated use testing at the formative level allows safety and usability issues to be uncovered sooner and designed out of the device before progressing too far into the product development cycle and validation stage, helping to avoid FDA rejection or clarification requests that might come if the study is not conducted in a proper environment.
ClariMed’s Simulated Use Environments
Across ClariMed, we offer realistic simulated use environments for home use and clinical use including in San Jose, CA, Cambridge, MA, and Chadds Ford, PA. Our newly renovated Cambridge, UK location features an upgraded state-of-the-art surgical suite and includes:
Multi-angle recording capabilities for comprehensive interaction analysis
Flexible study spaces that can simulate various healthcare environments
Dedicated surgical simulation suite
Dedicated reprocessing room
Full-functioning ambulance
State-of-the-art observation suite with real-time data capture capabilities
Advanced environmental controls for precise testing conditions
Reach out to us today to book our spaces and team for your simulated use studies.
References:
