Bionic leg helps amputees walk

A new, lightweight bionic leg uses AI to help users to walk longer and with less stress

Spotted: Readers of a certain age may remember hit TV show, the “Six Million Dollar Man,” whose bionic limbs allowed him to jump farther and run faster than the villains around him. Now, researchers in Utah may have created the first real bionic device – a self-powered prosthetic leg with an on-board computer. 

The bionic limb was developed by a University of Utah team, led by mechanical engineering assistant professor, Tommaso Lenzi. The leg uses sensors, motors, and artificial intelligence, to give the user the ability to walk longer and with less stress on the body than with a non-powered prosthesis. 

The leg uses custom-designed force and torque sensors, accelerometers and gyroscopes to determine its position in space. These inputs are used by the computer to perceive the environment and the user’s motions, step length and walking speed. Based on this real-time data, it then provides the right amount of power to the motors in the joints, to assist them in moving.

To keep the weight down, the team designed the leg so that all of the elements mesh together, like gears on a bike. The limb is built of lightweight aluminium and titanium and uses small, built-in batteries. Speaking to the University of Utah, Lenzi says: “If you walk faster, it will walk faster for you and give you more energy. Or it adapts automatically to the height of the step. Or it can help you cross over obstacles.” 

While the new leg is lighter than other bionic legs in development, it is not the only one. ETH Zurich recently developed a limb that mimics how nerve endings communicate with the knee, and a smart bionic hand has been developed by a team at Newcastle University.