Take a look at my idea: http://myhitthoughts.blogspot.com/2010/11/my-device-proposal.html
Patient ID QR codes:
- Scannable in all directions
- Small size
- Can be repeated
- Better read when bent
- More information
On wrist band:
This has already been done!
http://salmapatel.com/healthcare/qr-code-on-hospital-wristband
