DAP is often associated with fluoroscopy time within cardiology. I think, the reference to screen time means fluoroscopy time here.

Fluoroscopy

This is useful for both diagnosis and therapy and occurs in general radiology, interventional radiology, and image-guided surgery. In its simplest form, a fluoroscope consists of an X-ray source and a fluorescent screen, between which a patient is placed. However, since the 1950s most fluoroscopes have included X-ray image intensifiers and cameras as well, to improve the image's visibility and make it available on a remote display screen

https://en.wikipedia.org/wiki/Fluoroscopy

Relationship Between Fluoroscopic Time, Dose–Area Product, Body Weight, and Maximum Radiation Skin Dose in Cardiac Interventional Procedures

https://www.ajronline.org/doi/10.2214/AJR.04.1653

Dose area product (DAP) is a quantity used in assessing the radiation risk from diagnostic X-ray examinations and interventional procedures. It is defined as the absorbed dose multiplied by the area irradiated, expressed in gray-centimetres squared (Gy·cm2[1] – sometimes the prefixed units mGy·cm2 or cGy·cm2 are also used).

https://en.wikipedia.org/wiki/Dose_area_product