Case has one placed in clear folder? (7)

I believe the answer is:
patient
'case' is the definition.
(a medical case)
'one placed in clear folder?' is the wordplay.
I cannot really see how this works, but
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
'clear' could be 'patent' (synonyms) and 'patent' is located in the leftover letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'has' is the link.
Can you help me to learn more?
(Other definitions for patient that I've seen before include "One getting medical care" , "One receiving medical care" , "convalescent" , "Calm" , "case for treatment" .)