Pleasure Helmets

I'm wondering if it's possible to create a helmet that emits signals that focus on and stimulate the pleasure centers of the brain such that users would experience more bliss than is possible with the best drugs known to man. The device would have to have a timer since nobody could be trusted to take it off on their own. And you'd have to warn people not to drive or operate heavy machinery while using the stimulator. I reckon each stimulator would have to be custom fitted to the skulls of users. We'd sell them from kiosks in malls, the ones where Dippin' Dots used to be.