Human Factors and Usability Studies for Medical Devices
REGHELPS plans and runs usability engineering for medical devices and IVDs: use specification, use-related risk analysis, formative evaluations and summative human factors validation studies with representative users, documented in a usability engineering file ready for EU MDR, IVDR and FDA review.
What is human factors and usability engineering?
Human factors and usability engineering is the discipline of designing a device so that its intended users can use it safely and effectively, in its real use environment, without errors that could cause harm. Regulators treat it as part of risk management, not as a matter of user comfort.
The process is set out in IEC 62366-1. It starts by defining who uses the device, where and for what, identifies tasks where a use error could cause harm, improves the design through formative evaluations, and ends with a summative evaluation that proves the final user interface is safe.
What EU MDR, IVDR and FDA require
The three frameworks align closely. One well-run usability programme can support all of them.
| Topic | EU MDR and IVDR | US FDA |
|---|---|---|
| Legal basis | Annex I GSPR 5, plus GSPR on lay users, information supplied and self-testing | Design controls in 21 CFR 820 QMSR and human factors guidance |
| Standard | EN 62366-1 (harmonised) | IEC 62366-1 recognised; FDA guidance applies |
| Key deliverable | Usability engineering file in the technical documentation | Human factors / usability engineering report in the submission |
| Summative evidence | Summative evaluation of selected hazard-related use scenarios | Human factors validation testing of critical tasks |
| Special focus | Lay users and self-testing devices | Critical tasks, new user interfaces and home use |
The IEC 62366-1 usability engineering process
Nine linked steps, from understanding your users to proving the final design is safe.
Formative vs summative usability evaluation
Formative work finds problems early, when they are cheap to fix. Summative work proves the final design is safe.
| Formative evaluation | Summative evaluation (HF validation) | |
|---|---|---|
| Purpose | Find and fix use problems during design | Prove the final user interface is safe and effective |
| When | Throughout design and development | On the final, production-equivalent design |
| Methods | Expert reviews, cognitive walkthroughs, prototype tests, contextual inquiry | Simulated-use testing, or actual use where needed |
| Participants | Small groups, often 5–8 per round | At least 15 per distinct user group (FDA) |
| Output | Design recommendations | Pass or fail against acceptance criteria, with root cause analysis of use errors |
How large does your usability study need to be?
Every device needs usability engineering. This flow helps decide how much summative testing to plan.
How a summative usability study runs
A typical human factors validation study, from protocol to final report.
Our human factors and usability process
REGHELPS runs usability engineering as a complete service, from first analysis to the summative study report.
- 1
Gap assessment
StartWe review your existing usability records, risk file and user interface against IEC 62366-1 and FDA expectations.
- 2
Use specification and user research
UsersWe define user groups and use environments through interviews and contextual inquiry.
- 3
Task analysis and URRA
RiskWe map every task and build the use-related risk analysis that identifies critical tasks.
- 4
Known use problems
DataWe review complaints, adverse event databases and literature for similar devices.
- 5
Formative evaluations
DesignWe run expert reviews and prototype tests and give clear design recommendations.
- 6
Summative study
ValidationWe write the protocol, recruit participants, run sessions and analyse results.
- 7
Usability engineering file
DocumentationWe compile the file and write the HF/UE report for EU and FDA submissions.
- 8
Reviewer questions
SupportWe answer Notified Body and FDA questions on usability.
Common usability engineering findings
Our human factors and usability services
Human factors and usability FAQs
Which standards apply to human factors and usability for medical devices?
The main standard is IEC 62366-1:2015 with Amendment 1:2020, harmonised in Europe as EN 62366-1. IEC/TR 62366-2 gives practical guidance. In the USA, FDA expects its human factors guidance to be followed, and in the EU, MDR and IVDR Annex I (GSPR 5) require use-related risks to be reduced as far as possible.
What is the difference between formative and summative usability evaluation?
Formative evaluations happen during design to find and fix use problems early, using methods such as expert reviews, cognitive walkthroughs and early prototype tests. The summative evaluation, called human factors validation testing by FDA, is done on the final design to show that critical tasks can be performed safely by representative users.
How many participants are needed for a summative usability test?
FDA guidance recommends at least 15 participants for each distinct user group, such as clinicians, nurses, patients or lay caregivers. EU Notified Bodies generally accept the same approach when it is justified in the usability engineering file.
Do all devices need a summative usability study?
IEC 62366-1 requires summative evaluation of the selected hazard-related use scenarios for every device. How large it must be depends on risk. FDA expects human factors validation data in submissions for devices with critical tasks, especially new user interfaces, home-use devices and devices used by lay people.
Can a usability study replace clinical evaluation?
No. A usability study shows that users can operate the device safely and effectively. Clinical evaluation shows that the device is safe and performs as intended in patients and delivers clinical benefit. Both are needed, and their findings should be consistent.
What is a use-related risk analysis (URRA)?
A URRA lists every user task, the potential use errors for each, the resulting harms and their severity. It identifies critical tasks and links usability engineering to the ISO 14971 risk management file. FDA increasingly expects a URRA in submissions.
What is a user interface of unknown provenance (UOUP)?
It is an existing user interface that was not developed under IEC 62366-1, often on legacy devices. Annex C of IEC 62366-1 describes a simplified process to evaluate it using post-market data and a focused risk assessment.
Can you run usability studies for IVDs and self-tests?
Yes. IVDs, especially self-tests and near-patient tests used by lay people, have specific usability requirements under IVDR Annex I. We design studies with representative lay users, including reading and interpreting results.
Need a usability study your regulator will accept?
Share your device, user groups and target markets using the form below and we'll propose a usability plan and budget.
