User interface

Because labeling and training materials are part of the user interface, changing the instructions can be a user interface change that needs human factors review. Under FDA's 510(k) change guidance, user interface changes can also affect whether a new submission is needed.

means by which the USER and the MEDICAL DEVICE interact Note 1 to entry: ACCOMPANYING DOCUMENTATION is considered part of the MEDICAL DEVICE AND ITS USER INTERFACE. Note 2 to entry: USER INTERFACE includes all the elements of the MEDICAL DEVICE with which the USER interacts including the physical aspects of the MEDICAL DEVICE as well as visual, auditory, tactile displays and is not limited to a software interface. Note 3 to entry: For the purposes of this standard, a system of MEDICAL DEVICES can be treated as a single USER INTERFACE.

IEC 62366-1:2015+AMD1:2020, clause 3.26

User interface is defined as the means by which the user and the medical device interact (section 3.26) o Note 1 to entry: Accompanying documentation is considered part of the medical device and its user interface. o Note 2 to entry: User interface includes all the elements of the medical device with which the user interacts including the physical aspects of the medical device as well as visual, auditory, tactile displays and is not limited to a software interface. o Note 3 to entry: For the purposes of this standard, a system of medical devices can be treated as a single user interface.

MDCG 2021-6 Rev.1, Question 17 (quoting EN 62366-1)

Means by which the user and the medical device interact. [Note: Examples include packaging, labeling, training materials, physical controls, display elements, alarms, and logic of operation of each device component.]

FDA guidance: Applying Human Factors and Usability Engineering to Medical Devices (August 2026), Section 3, Definitions

A device user interface includes all points of interaction between the product and the user, including elements such as displays, controls, packaging, product labels, and directions for use.

FDA guidance: Deciding When to Submit a 510(k) for a Change to an Existing Device (October 2017), Appendix C, Significant Terminology