The most innovative technology for Valentine's Day since Cupid figured out how to keep a bow on his back has arrived.

Japanese lingerie company Ravijour has developed a bra which can be unhooked only if the woman wearing it is in love.

The ‘smart bra’ keeps tabs on the woman’s heart rate, which it then sends to an app. If the heart rate reaches a level consistent with being in love, the bra magically pops open (somehow, we think the heart rate may also be triggered if, say, Brad Pitt walked into the room). How the bra can determine the specific heart rate for individual women remains about as much of a mystery as the age-old question, "Why didn't he call?"

Ravijour claims the smart bra will be a welcome way for ladies to fend off men, although there are issues that develop when the heart rate increases in non-romantic situations. No woman wants her bra to open up while she’s running on a treadmill, giving a big presentation at work or trying to get out of a speeding ticket (well, maybe the speeding ticket…).