Bluetooth SMART : heart rate sensor... protocole ?

Hello,

I would like to interface this sensor (like this one in France) through an HC-O6 which is well know here !

I try to find reference on the protocol used by this sensor sold by many sport vendor and for which we can found many applications for androïd, but till now I am not able to found the protocol used by these sensors. Any tips will be welcome !

Jean-Marie