The Download: mind-controlled prosthetics, and the price of AI training data

What's new: When someone loses part of a leg, a prosthetic can make it easier to get around. But most prosthetics are static, cumbersome, and hard to move. A new neural interface connects a bionic limb to nerve endings in the thigh, allowing the limb to be controlled by the brain. How they did it: First, patients undergo surgery to connect shin muscle, which contracts to make the ankle flex upward, to calf muscle, which counteracts this movement. The prosthetic can also be fitted at this point.