nature and steal concepts that emulate that functionality. what he is wearing here is an emlation of the biological knee joint. >> can we see the whole thing then? >> it extends all the way up. >> we spend years developing prototype after prototype after prototype, iterating, iterating, and iterating. often in the beginning it doesn't work at all. it is farce worse than commercial devices. by the end we often come above the water and there is a clinical benefit. >> when my legs were amputated, obviously a lot of critical nerves were amputated, were cut. those nerves used to feed muscles i used to have in my lower legs what we want to do in this field of bionics long-term is be able to talk to nerves, both collecting how a person wants to move and sending it out to a bionic device and stimulating into the nerves, into the nervous system so that