We travel with medical equipment that requires inspection. Not all medical equipment will, for example a CPAP will not.
We have followed Special Services advice, and when we get to security at the port, tell them we have medical equipment that Special Services says we are to take to Guest Services on board the ship to have it inspected; we carry a copy of the email that Special Services sent us explaining what to do and one time we have had to show that note as security wanted to confiscate the equipment and send it for inspection themselves, and there was no way I was letting that happen.
So it goes through security screening like the rest of our carryon luggage and then we take it to guest services (not our first stop, but either before we get our room or shortly after we stop at guest services with it). At guest services I explain what it is and what I was directed to do and that it needs inspection. I have it in its own bag with a luggage tag on it with out name and sateroom number and inside the bag a sheet of paper with our name and stateroom paper and the words MEDICAL EQUIPMENT. I also have a "MEDICAL" tag for the outside of the bag. On the note inside the bag I handwrite "This is medical equipment; please handle with clean hands/gloves and return it to our room as soon as possible. Thank you."
The bag with equipment in it is returned to our room early that evening.
While at guest services we also pick up the extension cord we arranged to borrow. There is a $50 deposit that they will refund when you return it to guest services.