Minor test involving hospital equipment (7)
I believe the answer is:
trivial
'minor' is the definition.
(I've seen this before)
'test involving hospital equipment' is the wordplay.
'test' becomes 'trial' (synonyms).
'involving' is an insertion indicator.
'hospital equipment' becomes 'IV' (intravenous drip).
'trial' enclosing 'iv' is 'TRIVIAL'.
(Other definitions for trivial that I've seen before include "Of little substance or significance" , "Trifling" , "Insignificant" , "Worthless" , "Of little consequence" .)