Why demonstrate the system with a drone? "It's more manageable to test in protocol than it is to do on a patient with a prosthetic arm," he says. In the published paper, the pilot is illustrated as someone in a wheelchair, sitting in front of a laptop that's streaming back everything the drone sees. A thought-controlled wheelchair would probably help that person out more, but ground-bounded wheelchairs rarely encounter something both drones and arms deal with every day: precisely navigating three dimensional space. Flying a drone through a hoop turns out to be good practice for maneuvering a hand to a mouth, say, or putting an arm through a sleeve.