An electronic apparatus (1) including a display generation unit (110) configured to generate a display area (210) in a user interface, the display area being configured to display a 3-D model of a patient's face and a 3-D model of a patient interface device fitted to the 3-D model of the patient's face； and an interaction map unit (160) configured to generate an interaction map tool (260) in the user interface and to calculate an interaction map between the patient's face and the patient interface device indicating levels of an interaction characteristic between the patient's face and the patient interface device, wherein the interaction map tool is operable to toggle display of the interaction map in the user interface.
