New prosthetic leg controlled by the mind

Doctors in Europe have unveiled the first viable brain-controlled bionic leg in Copenhagen, working without external computers and working much more like a real leg than ever before.

We've seen plenty of brain-controlled prosthetic limbs before in labs, but they come with a couple of problems. They rely on electrodes implanted on the brain, which plug into an external computer to interpret signals. The Proprio Foot makes this a more realistic prospect to use in the real world, as the surgery to implant its hardware takes only 15 minutes and it doesn't require an external power source.

So how does it work? The two implanted myoelectric sensor (IMES) modules are attached to nerves in the leg with small incisions (only one centimetre incisions). Magnetic coils are placed in the socket of the prosthetic, meaning they can draw power from the current generated, eliminating the need for some form of battery.

The motorised angle joint moves forward and back depending on the signals received from the patient. With that, the user can distribute their weight more efficiently and get around better because of it. What's also great about this way of working is getting the patient to use muscle contractions in the remaining limb to activate it. This leads to improved strength and a decrease of being prone to atrophy.

So far, a small group of testers have loved it, and the team are planning to go into clinical trials and sell the Proprio Foot as a medical device after approval. Ossur hopes to bring it to market in as little as three years.