cool project
although it seems highly event specific
maybe you can complete the "package" so fields can adopt this as a valid game mechanic
if I understand correctly you just need some disposable RFID elements to scan and give out to players, and give this device to a medic, and you will have accurate counting of number of heals
although, it seems the same function can be fulfilled by people simply remembering how many times they died, or watching a watch for countdowns
and this "high tech solution" will require training and extra workload and budget and problems mainly from all the RFIDs you are giving out, they can be lost in-game etc