Thought-controlled bionic limbs are still a way off (though not far). In the meantime, a project at Vanderbilt University is building the next best thing: a “smart” prosthesis that gives amputees a more natural gait.
Michael Goldfarb, a professor of mechanical engineering, at Vanderbilt's Center for Intelligent Mechatronics, has been working for several years with Craig Hutto, who lost his leg in 2005 when he was attacked by a shark. Hutto, who is a lab assistant, has offered valuable input on what works and what doesn’t work for amputees. That has gone a long way towards making the bionic leg comfortable and workable in real-world conditions.
The bionic limb is a step beyong conventional prosthetic devices. It has a computer with a lot more processing power. For instance, Motors in the leg are controlled by sophisticated sensors that detect the user’s motion and move in unison. The hardware and software routinely checks if the wearer is stumbling, and if he is, causes the leg to plant itself in a stable spot.
Advances in battery and motor technologies have made it possible to run the bionic leg for days on a single charge. It;s also light, weighing about nine pounds, which makes a big difference when trying to climb stairs. Many amputees have a tough time with stairs and slopes because the artificial limb is so heavy. It's also a lot less cumbersome than exoskeleton-based designs.
All this adds up to a more natural gait.
So far, the leg has gone through seven iterations –- fifteen if you count the work done on the electronics alone. Goldfarb's team is also working on arms and an exoskeleton to aid in physcial therapy. But eventually, such prostheses will likely become commonplace, and for many people like Craig Hutto, the act of taking a stroll won't be so daunting anymore.
Image: John Russell, Vanderbilt University. A close up of Craig Hutto, wearing the leg.