NMPA published the “Medical Devices Usability Engineering Guideline” on March 19, 2024. NMPA believes that, in improving the usability and the design of devices to minimize potential use errors and resulting harm, manufacturers will be able to assess and reduce risks associated with medical device use.
From October 8, 2024, submission materials of certain medical devices will have to include the usability engineering information.
Referenced by FDA guidance of “Applying Human Factors and Usability Engineering to Medical Devices”, “Content of Human Factors Information in Medical Device Marketing Submissions”, etc. the NMPA guideline is to keep up with the international standards.
Application Scope
This guideline is applicable for usability engineering design and related submission of Class III and Class II medical devices. The following devices are included in the trial list:
- Cardiac Radiofrequency Ablation Equipment
- Cardiac Radiofrequency Ablation Catheter
- Cardiac Surgical Radiofrequency Ablation Equipment
- Cardiac Surgical Radiofrequency Ablation Clamp/Pen
- Surgical Navigation and Positioning System (with Robotic Arm and End Effector)
- Endoscopic Surgical System
- Vascular Interventional Surgery Control System
- Therapeutic Ventilator
- Home Ventilator
- External Defibrillator
- Hemodialysis Equipment
- Continuous Blood Purification Equipment
- Artificial Liver Device
- Implantable Circulatory Assist Device
- Implantable Drug Infusion Device
- Infusion Pump (Class III)
- Needle-Free Injector
- Infusion Pump (Class III)
- Insulin Pump (Class III)
Basic Principles
The document establishes three principles for manufacturers to consider:
- Usability Engineering Positioning
Usability of medical devices is integral to their safety and effectiveness, requiring analysis and control of usage risks based on intended use, usage scenarios, and core functionalities. Usability engineering should be conducted in conjunction with user and usage scenario considerations to ensure the safety and effectiveness of medical device usage.
- Risk-Oriented Approach
Issues with usability of medical devices can lead to usage risks, affecting their safety and effectiveness. Enhancing usability, especially in scenarios involving new usage methods, steep learning curves, non-professional users, complexity of operations, life support, drug-device combination, emergency situations, home use, and special populations, is essential to mitigate usage risks. Usage risks are categorized based on the severity of harm they may cause, ranging from high to low. Risk management, including methods such as Failure Mode and Effects Analysis (FMEA) and Fault Tree Analysis (FTA), should be integrated with usability engineering to control usage risks and ensure they remain at acceptable levels.
- Lifecycle Management
Usability engineering considerations should be integrated throughout the entire lifecycle of medical devices. Prior to market entry, usability engineering should be incorporated into the design, development, and risk management processes to identify and mitigate foreseeable usage risks. Post-market, usability issues, including adverse events and recalls, should be analyzed to address unforeseen risks and further improve the safety and effectiveness of medical device usage. Usability engineering is an iterative process, and traceability analysis within the quality management framework is necessary to ensure accountability and continuous improvement.
Usability Engineering Process
Usability engineering requires applicants to establish a comprehensive process within their quality management system. This process involves activities like requirement analysis, design, implementation, validation, confirmation, and changes, with risk management and traceability analysis embedded throughout. Each activity necessitates corresponding documentation. Requirement analysis defines user interface concepts and forms specifications, while design translates these into standards. Implementation involves realizing design specifications, incorporating risk management. Validation ensures adherence to design, while confirmation ensures meeting requirements and acceptable risks. Change activities include evaluation, planning, implementation, validation, confirmation, risk management, traceability analysis, and documentation control.
User Interface Validation and Confirmation
Validation and confirmation shall consider special user groups and environments. Validation methods include expert reviews, cognitive walkthroughs, and formative usability testing. Confirmation methods include summative usability testing and comparative evaluation with equivalent medical devices. Reports detailing the procedures and findings of these evaluations are necessary for regulatory purposes.
Technical Considerations
NMPA pointed out six areas to be given for special consideration:
- Clinical Trials
Clinical trials must prioritize the protection of participants’ rights, particularly patients. Certain critical tasks in user interface confirmation testing might pose risks of severe harm or death to trial participants and thus cannot be executed within clinical trials. Additionally, the specific requirements for the number of participants in user interface confirmation testing might not align with the number available in clinical trials. Therefore, clinical trials usually cannot replace user interface confirmation testing but can supplement and support it.
- Imported Medical Devices
Due to differences between domestic and foreign users and usage scenarios, imported medical devices may require specific user interface confirmation work to ensure their safety and effectiveness in China. Analyzing differences in usability engineering requirements between countries is crucial. For high-risk devices, an analysis of these differences is necessary to determine whether imported user interface confirmation data are acceptable. If not, confirmation testing may need to be conducted in China.
- Pre-existing User Interfaces
Pre-existing user interfaces, lacking complete usability engineering lifecycle control, must meet specific quality control requirements during medical device usability engineering processes. Their usage requires careful consideration of post-market usage issues and compliance with applicable standards.
- Combination Usage
For medical devices that require combination usage, overall user interface confirmation should be conducted at the system level. Documentation submission for registration should align with the risk level associated with the combination usage.
- Standards
International, national, and industry standards related to usability engineering, ergonomics, and safety should guide medical device usability engineering activities. These standards outline process requirements and may include user interface specifications and safety considerations.
- Usability Engineering Changes
Changes in medical device usability engineering should undergo verification and confirmation activities aligned with quality management system requirements. Substantial changes to users, usage scenarios, or user interfaces usually necessitate registration amendments. Other usability engineering changes should be controlled through quality management systems and documented for system audits or registration amendments. If changes affect the risk level, corresponding documentation should be provided for registration.