Tight band forms part of medical device (9)
I believe the answer is:
stringent
'tight' is the definition.
(synonyms)
'band forms part of medical device' is the wordplay.
I cannot really understand how this works, but
'band' could be 'ring' (a ring is a band of metal) and 'ring' is found within the answer.
'part' could be 'tent' (I have seen 'part of camp' mean 'tent' so perhaps 'part' could also mean 'tent') and 'tent' is found within the remaining letters.
A single letter 's' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for stringent that I've seen before include "(Rule) allowing no discretion" , "Harsh" , "binding" , "Uncompromising" , "Tight" .)