NMPA published the “Medical Devices Usability Engineering Guideline” on March 19, 2024. Below is the “Interpretation on Device Usability Engineering Guideline” issued on March 27, 2024.
For the first batch devices included in the Usability Engineering Guideline, please click HERE
Background
Human-machine interaction is essential for the intended use of medical devices, which is a prominent characteristic of such devices. Data indicates significant issues with the usability of medical devices, leading to considerable usage risks, mainly due to usability issues.
In recent years, regulatory agencies such as those in the United States and the European Union have issued multiple usability guidelines and standards, gradually strengthening regulatory requirements for medical device usability. China officially implemented the GB 9706.1-2020 series of standards on May 1, 2023, which also clearly outlines usability requirements.
Application Scope
The guideline applies to the registration declaration of usability engineering for Class II and Class III medical devices and do not apply to in vitro diagnostic reagents. Applicants can refer to requirements in the guideline to conduct all usability engineering work for medical devices.
User Interface Verification and Validation
User interface verification and validation are important components of medical device design verification and validation, where user interface verification is part of design verification and user interface validation is part of design validation. From the perspective of usability engineering, user interface verification is also known as formative evaluation, and user interface validation is known as summative evaluation.
User interface verification can use or combine methods such as expert review, cognitive walkthrough, and formative usability testing. User interface validation can use or combine methods such as summative usability testing and comparative evaluation with equivalent medical devices. In principle, summative usability testing methods should be used for entirely new products, while mature products can use comparative evaluation methods with equivalent medical devices.
Usability testing refers to the evaluation of user interfaces based on observed data and interview data from users completing operational tasks in expected usage environments, i.e., user interface testing conducted in simulated or real usage environments. Applicants for registration can conduct summative usability testing using methods such as simulated testing (based on simulated usage scenarios or self-built usability laboratories) and on-site testing (based on real usage scenarios), or commission third-party usability laboratories (including testing institutions, universities, research institutions, etc.) to conduct summative usability testing.
Equivalent medical devices refer to similar medical devices that have been registered and marketed domestically and are essentially similar in terms of intended use, target population, structural composition, users/user groups, user characteristics, usage location, environmental conditions, key tasks, human-machine interaction methods, user training, etc. Applicants for registration can refer to the methods of comparative clinical evaluation for similar varieties and conduct comparative evaluations of equivalent medical devices based on differences between the applicant’s medical device and equivalent medical devices, as well as new usage risks.
Relationship with Clinical Trials
Certain key task tests in user interface validation may cause severe harm or death to subjects and cannot be performed in clinical trials. At the same time, user interface validation testing has specific requirements for the number of test participants, which may not always be met in clinical trials. Therefore, clinical trials generally cannot replace user interface validation testing but can support and complement it.
In special circumstances, if clinical trials can meet the requirements of summative usability testing, they can be used as user interface validation testing.
Imported Medical Devices
Imported medical devices have differences in users and usage scenarios between China and foreign countries, and there are also differences in registration requirements for usability engineering between China and foreign countries. Therefore, imported medical devices generally need to conduct user interface validation work in China based on the usage risk level unless supported by detailed data proving that the differences between China and foreign countries have no significant impact on user interface validation.
For medical devices with high usage risks, applicants for registration need to conduct a comparative analysis of usability engineering differences between China and foreign countries based on users, usage scenarios, and registration requirements, and submit corresponding usability registration declaration materials according to the analysis results, and conduct user interface revalidation if necessary.
For medical devices with medium and low usage risks, applicants for registration only need to submit usage error assessment reports and overseas usability engineering research materials.
Ready-Made User Interfaces
Ready-made user interfaces refer to user interfaces for which applicants for registration have not conducted (or cannot prove) complete usability engineering lifecycle control.
The safety and effectiveness of ready-made user interfaces can be confirmed using comparative evaluation methods with equivalent medical devices, focusing on analyzing the usage problems of ready-made user interfaces after they are marketed. If confirmation cannot be obtained, a reconfirmation of self-developed user interface requirements is required.
Multiple ready-made user interfaces can be used for medical devices, and after confirming the safety and effectiveness of each ready-made user interface, the safety and effectiveness of all user interfaces should be confirmed from the perspective of the entire medical device product.
Combination Use
If the expected purpose of a medical device can only be achieved through the combined use of a host with dedicated active accessories, a host device with dedicated passive consumables, a host device with dedicated reagent kits, or the combination use of medical devices and drugs, the applicant for registration needs to conduct user interface confirmation for the medical device system as a whole and submit usability engineering research materials for the medical device system in their respective registration units, or submit corresponding usability engineering research materials based on the usage risk level.
Application Instructions
From October 8, 2024, certain medical devices intended for submission should submit corresponding usability declaration materials according to specific circumstances. Medical devices already under review do not need to submit usability declaration materials.
For medical devices intended for registration, those with high usage risks should submit usability engineering research reports, while those with medium and low usage risks should submit corresponding registration declaration materials if the product guidelines have usability or usability-related requirements (such as simulated usage), otherwise, usage error assessment reports should be submitted in other cases.
For medical devices intended for registration changes, there is no need to supplement usability engineering research materials for the products before changes. If substantial changes are made to users, usage scenarios, or user interfaces, usability declaration materials should be submitted according to the previous requirements.
For medical devices intended for registration renewal, there is generally no need to submit usability declaration materials.