A team from the University of Pittsburgh is working to connect patients with artificial limbs and the nervous system to give patients a sense of touch.
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Scientists want artificial limbs to feel real. Scientists are creating bionic arms and legs that provide a sense of touch. John Hamilton of NPR reports on the work of researchers at the University of Pittsburgh.
John Hamilton, Byline: The group has more than 80 people from 10 different labs. Lee Fisher is a bioengineer who runs one of those labs. He says their inspiration came from Star Wars.
Lee Fisher: When Luke Skywalker gets that mutilation, they give him this new hand, and this – you can’t say it’s not his own hand.
HAMILTON: One reason – Luke’s prosthetic arm feels the same pressure and pain as usual. Fisher says we rely on the feeling of touch even for simple tasks, such as holding a cup of coffee. So Pittsburgh scientists are looking for ways to get sensitive information from artificial limbs and transmit it to the user’s own nervous system. For example, Fisher’s lab is using a device attached to a person’s spine.
Fisher: It basically looks – almost like a spaghetti noodle. They can be inserted through a needle.
Hamilton: The device is designed to stimulate the nerves of people with chronic pain, but Fisher’s lab is using it to relay information from artificial hand or foot sensors. He says the technique is to stimulate the same nerve fibers that were once attached to a person’s own organ.
Fisher: The first thing we try and understand is, how does the stimulus feel? So can we create a sensation that feels like it’s coming from their missing arm or their missing leg? Can We Change Intense Feelings?
HAMILTON: A four-person survey says the answer is yes Pat Bain, whose right hand was amputated to stop the infection, described in a video produced by the university how the stimulus felt.
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Pat Bain: I know there are no hands, but I can feel it. They can feel the palm of my hand that it is the palm of my hand.
Hamilton: Artificial legs and feet work better with the feeling of touch. “Because we rely on the constant response of our feet to stay straight,” Fisher said.
Fisher: We’re basically like an inverted pendulum that you have to rotate to maintain balance, and the sensitive response of your feet allows you to do this.
HAMILTON: Fisher says a test that adds an artificial leg reaction could help at least one limb.
Fisher: We’ve seen improvements in her balance while standing, some stability in her walking, and some improvement in her confidence – so how comfortable she feels.
Hamilton: The feeling of touch can help even those whose limbs are numb. For years, the Pittsburgh group has been teaching paralyzed people to control a robotic arm using only their thinking.
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HAMILTON: Jane Collinger, a rehabilitation scientist, says they now want to add a touch of touch to this robotic weapon called the Kuka.
Jane Collinger: Kuka is an art robot. We chose it because it’s fast, and it can be fairly flexible.
HAMILTON: Theoretically, Collinger says, robots can help a paralyzed person regain some independence.
Collinger: Being able to feed yourself – isn’t it? – Being able to make a meal, be able to dress, play, do anything, really, whatever you want.
HAMILTON: But these kinds of things are difficult when a person has to rely only on their eyes to know what an artificial hand is doing. Robert Gant, a biomedical engineer, says the feeling of touch makes it a lot easier.
Robert Gantt: It takes half the time for someone to pick up objects and move them around. And many of those trials actually happen fast enough to be considered what we would call competent-body performance.
HAMILTON: So far, scientists can only provide a very basic sense of touch. Gunt says it’s good enough to know when there’s weight on one foot or when an arm is facing something.
Gant: Our ability to differentiate between different types of objects, textures, surfaces – this is a difficult problem.
HAMILTON: Tough, he says, but not out of reach.
John Hamilton, NPR News.
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