I had the privilege of seeing Dean Kamen speak last year about the DEKA arm. One of the things he lamented was that the FDA had to decided not to classify the arm as Class I, and as such it was getting caught up in drawn out regulation when there were people he felt it could help right now.
Video demo of the updated, 3rd-generation DEKA arm. http://youtu.be/auetIxOaSe8