[shadesandcolour]

QR code on the wall is probably better in this case because it's easier to spot from a head mounted display. The barcodes on wristbands are used mainly for patient ID when administering medications, where the user is close to the patient. Being able to walk into a room and look at the same place each time has the advantage here.

[keithflower]

Maybe. But the ERs I work in rarely have one patient rooms, and the patients have a tendency to wander.