The big medical supply place in town is called Perkins. I believe they have a location in Sebastian (which would be closer to the resort than Vero itself.)
I'll see if I can find the number. I would give them a call and see if they could drop one off at the resort for the duration of your stay. I see their trucks all over town so I'm sure they would.
772-388-5251
www.perkinsmedicalsupply.net
You may also want to call the resort and see if they have one.