http://bit.ly/HbJvuA An anesthesiologist helped analyze Bane's mask and came up with some cool theories on how it might work in TDKR. After seeing the movie a few times, I've been wondering how he can replenish his mask with a painkilling gas. I kind of wish Nolan had explained the science behind Bane and his mask (wasn't there an outtake online with Wayne and Fox discussing this?) but I guess he left it up to the viewers to either figure it out themselves or just accept it for what it is. I feel it might be best to accept it at face value and not question it too much, but the theories this doctor comes up with are pretty interesting from a scientific point-of-view.