Article Summary
- Japan’s enforcement of JIS T 62366-1:2022 has made usability engineering increasingly important for medical device regulatory preparation.
- Global manufacturers may be able to adapt existing HFE/UE data, but must justify Japan-specific use context, localization, and risk differences.
- Testing with Japanese users can help identify language, workflow, and cultural risks before PMDA submission.
For global medical device manufacturers, usability engineering is now an important part of regulatory preparation in Japan. With the enforcement of JIS T 62366-1:2022 from April 1, 2024, usability engineering is expected to be addressed as part of the medical device development and risk management process.
This article clarifies the current landscape in Japan and what it means for international teams preparing medical device submissions to PMDA.
1. Japan’s Regulatory Approach to Usability
Japan’s medical device regulatory system is overseen by PMDA, under the Ministry of Health, Labour and Welfare (MHLW). While PMDA has published guidance documents and overview materials explaining JIS T 62366-1, these resources focus primarily on what is required rather than providing detailed implementation guidance or templates.
PMDA applies key international standards to guide usability considerations:
- JIS T 62366-1:2022 – Japan’s Industrial Standard for applying usability engineering to medical device design. Harmonized with IEC 62366-1:2015, this standard defines a structured process for identifying and minimizing use-related risks through user-centered design.
- JIS T 14971:2020 – Japan’s harmonized standard based on ISO 14971:2019 for risk management of medical devices, which includes identifying and evaluating use-related hazards.
2. What Medical Devices are Subject to Usability Engineering?
Usability engineering should be considered for all medical devices with user interaction, with the level of documentation depending on the device’s risk profile, user interface complexity, and submission pathway.
A common misconception is that usability engineering only applies to software-based or electronically controlled devices. In reality, any medical device with user interaction falls under the scope, regardless of whether it contains software or electronics. For example, accompanying materials are also considered part of the interface and must be evaluated for use-related risks.
Examples of accompanying materials include:
- Instructions for use
- Package inserts
- Training materials
- Maintenance and inspection manuals
3. PMDA Submission Pathways: Shonin, Ninsho, and Todokede
Understanding which submission pathway applies to your device is critical for determining the level of usability engineering documentation.
| Submission Type | Device Classification | Review Authority | Summative Evaluation Expectation |
| Shonin (Approval) | New or significantly modified Class III or IV devices, and certain high-risk Class II devices | PMDA | Required – Full summative validation expected |
| Ninsho (Certification) | Standard Class II devices | PMDA-registered Third-Party Certification Body (RCB) | Typically required – Extent depends on risk profile and user interface complexity |
| Todokede (Notification) | Low-risk Class I devices | No review – notification only submitted to PMDA | Generally not required |
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For Class II devices and above, typical submission documents now include:
- Application form
- Device summary and intended use description
- Risk management file (per JIS T 14971 / ISO 14971:2019)
- Clinical evaluation and performance testing data
- Labeling and Instructions for Use (IFU) in Japanese
- Quality Management System (QMS) documentation
- Usability engineering file (UEF) including:
- Use specification: Who will use the device, where, and for what purpose
- Use-related risk analysis (URRA): User tasks, potential use errors, harms, hazard-related use scenarios, risk control
- Formative evaluation summaries: Iterative testing results and design improvements
- Summative evaluation report: Final validation demonstrating safe and effective use
4. Can Foreign HFE/UE Data Be Used for Japan?
Rational Justification
Many global manufacturers with experience in FDA submissions or EU MDR compliance already conduct usability testing as a standard part of development. The good news is that existing HFE/UE work can often be adapted for PMDA submissions. However, to use foreign HFE data, it is important to provide the following:
- Equivalence of Use Context: Must prove that the intended users, use environments, and use scenarios in the foreign study are essentially equivalent to those in Japan.
- Localization Risk Assessment: Must demonstrate that Japanese-specific elements; such as language displays, unit notations (e.g., specific medical units), and localized labeling do not introduce new risks or use errors.
Integration with Risk Management
In addition to providing rationale for the above, usability engineering file must clearly link to your risk management file (per JIS T 14971). PMDA reviewers expect to see:
- Traceability: Use-related hazards identified in risk analysis must be addressed in summative testing
- Outcome-Based Evaluation: Summative evaluation is viewed as a confirmation of risk control effectiveness. Reviewers dislike conclusory statements like “safety was confirmed”; instead, documentation should state that the evaluation confirmed the design-based risk controls are effective for the identified hazard-related scenarios.
Cases Requiring In-Country Studies
Additional studies in Japan may be necessary for:
- Patient-facing Software as a Medical Device (SaMD): Software intended for use by patients rather than healthcare professionals.
- High-impact display results: Devices where the results shown on the display directly impact diagnostic or treatment decisions.
- UI misinterpretation risks: Any case where the Japanese-language User Interface (UI) might pose a risk of misinterpretation or lead to new use errors.
Why is it important?
Testing with Japanese users ensures that language, cultural context, and demographic factors are properly accounted for and may reveal use errors that wouldn’t surface in other testing environments abroad.
Conclusion
Japan’s medical device market is evolving rapidly. While HFE/UE resources and regulatory precedents remain more limited compared to the US or EU, usability is increasingly recognized as a critical element of medical device safety and effectiveness.
For international manufacturers, the April 2024 enforcement of JIS T 62366-1:2022 means usability engineering now needs to be considered as part of medical device development and regulatory preparation in Japan. Whether you are adapting existing HFE/UE work for Japan or starting from scratch, it is important to document use-related risks in a way that aligns with PMDA expectations and, where needed, evaluate the device with Japanese users.
Uism supports international medical device manufacturers with usability testing and research documentation in Japan. We help teams plan formative and summative studies, recruit Japanese healthcare professionals and patients, evaluate Japanese-language interfaces and IFUs, and prepare usability documentation aligned with JIS T 62366-1 and PMDA expectations.
If you are preparing a PMDA submission or assessing whether your existing HFE/UE data can be used for Japan, our team can help you identify the most appropriate next steps.
FAQ
Is usability engineering required for medical devices in Japan?
Yes. Conformance to JIS T 62366-1:2022 is mandatory for all medical device approvals and certifications in Japan as of April 1, 2024. This requirement ensures compliance with the requirements (specifically Articles 9 and 16) established by the Ministry of Health, Labour and Welfare (MHLW), which dictate that risks from use errors must be reduced as far as possible.
Does JIS T 62366-1 apply to Class I medical devices?
Yes. The standard applies to all medical device classes. While the level of documentation and the need for a final summative test may vary based on risk, the manufacturer must still follow a systematic usability engineering process to meet Japanese regulatory standards.
Is summative usability testing always required for PMDA submissions?
Summative evaluation is generally required for Class II, III, and IV devices. For Class I devices, summative testing is typically not mandatory, provided the manufacturer can rationally explain through risk analysis (JIS T 14971) that use-related risks are negligible. However, summative testing may still be suggested for Class I products if they are Software as a Medical Device (SaMD) or intended for general consumer/home use.
Can FDA or EU HFE/UE data be used for PMDA submissions?
Yes, but translation alone is insufficient. Overseas evaluation data can be leveraged if the manufacturer provides two specific rationales in the dossier:
- Equivalence of Use Context: Proving that the intended users, environments, and scenarios in the foreign study are essentially equivalent to those in Japan.
- Localization Risk Assessment: Confirming that Japanese language displays, specific unit notations, or cultural differences do not introduce new use-related risks.
When should usability testing be conducted with Japanese users?
Additional validation studies involving Japanese participants may be required in the following scenarios:
- For patient-facing SaMD or devices intended for home use by lay users.
- When device display results (e.g., AI-aided diagnostics) directly impact clinical decisions.
- Where the Japanese-language UI or localized labeling poses a unique risk of misinterpretation.
Are IFUs and labeling included in usability engineering?
Yes. The “user interface” is broadly defined to include all means of interaction between the user and the device. This explicitly includes Instructions for Use (IFUs), labels, packaging, training materials, and any other accompanying documentation. Because these are considered information for safety, their effectiveness must be verified during the usability engineering process.
