I read a couple weeks ago, that when the next tizen OS update comes out, it will start rolling out blood pressure monitoring in certain countries, as it gets approved, but that it will need to be calibrated with a cuff... I actually don't know much about blood pressure monitoring so I don't exactly know what monitoring with a cuff to calibrate it has to do or how that would work but I have used a blood pressure monitor before so if it's what I think then you would just take a blood pressure monitor measurement thing while wearing the watch and then input the results and then somehow that calibrates your watch I guess... But again that's if my limited knowledge is correct...