This is an article on the IET site reference RFID and the different types that can be used.

http://www.theiet.org/factfiles/it/rfid.cfm?type=pdf

The only thing with RFID is that it will not stop theft or the forgetful transfer persons. The one to have a look at is the microwave system as you can get a position on the item. Just dont know how it would affect older unscreened equipment that we all have in our hospitals.

Billy