It's used for patient examination (7)
I believe the answer is:
scanner
'examination' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for scanner that I've seen before include "Doccument copier" , "Imaging and reproductive device" , "Medical camera" , "Digitiser; hospital machine" , "Device used to help medical diagnosis" .)