‘Luke Skywalker’ bionic hand could help amputees feel again
To lose a hand is to lose part of yourself, said Gregory Clark, associate professor of biomedical engineering at the University of Utah. And while prosthetic hands have been in use for thousands of years, there is room for improvement.
Researchers at the University of Utah, with the help of other organizations including Blackrock Microsystems and DEKA, have been on a mission to do just that. They have developed a prosthetic system that will allow patients to regain their sense of touch.
“Traditional prosthetic hands lack sensory feedback, which makes them clumsy to control and makes them feel unnatural,” said Clark.
As a result, the team added sensory feedback to an advanced bionic arm called the LUKE arm. It’s named for the robotic arm Luke Skywalker receives in “The Empire Strikes Back.”
They used output from arm sensors to control the stimulation of sensory nerve fibers which convey information to the brain and create the sensation of touch. To re-create that sensation, electrodes were connected to the inside of nerves.
“The participants can feel over 100 different locations and types of sensation coming from their missing hand,” said Clark.
The sensations include different types of touch, such as pressure, flutter or vibration, temperature, and pain. According to Clark, users can also feel the location and contraction of their muscles, even though the muscles aren’t actually there.
“That’s because we can send electrical signals up the sensory fibers (biological wires) from the muscles, so the brain interprets them as real,” he said.
And just as the brain is able to interpret the electrical signals, the motor signals from the brain register with the LUKE as well.
Clark said that when a user thinks about moving their hand, whether they have one or not, the brain will send a motor signal down the nerves.
“If we record and interpret those motor
signals accurately, then the user can control a prosthetic arm naturally and intuitively, just by thinking about it — much as they used to do with their biological arm,” said Clark.
Keven Walgamott was a participant in the study. He used the arm for the first time in 2017.
“It almost put me to tears,” Walgamott said in the press release. “It was really amazing. I never thought I would be able to feel in that hand again.”
The next immediate step is to make the system portable so that take-home trials can be feasible.
The prosthetic is pending FDA approval, Clark said, but they are hoping to start take-home trials within the coming months. They are also hoping to make wireless versions so users don’t have to have wires sticking out as they do with the current model.
Commercial versions will take years to become available.
“Sensation restores not only the ability to feel again — it also partially restores the sense of feeling whole,” said Clark.