The MDR aims (among other things) to guarantee safe and innovative medical devices. In order to ensure safe use, some requirements are placed on the usability of your product. These can be found mainly in the “General Safety and Performance Requirements” (Annex 1 of the MDR). Since Annex 1 applies to all medical devices, you are obliged to address usability for compliance with the requirements made there.
Summative Usability Evaluation