Popular, healthier gadget some patients use (7)
I believe the answer is:
inhaler
'gadget some patients use' is the definition.
(piece of medical equipment)
'popular healthier' is the wordplay.
'popular' becomes 'in' ('in' can mean trendy).
'healthier' becomes 'haler' ('hale' can be similar in meaning to 'healthy').
'in'+'haler'='INHALER'
(Other definitions for inhaler that I've seen before include "Asthmatic's aid" , "Respiratory aid" , "Spraying device to aid breathing" , "Device for, eg, asthma sufferer" , "Medical device" .)