BREAKTHROUGH FOR THE DISABLED`Bionic' arm brings back sense of touchTechnology links computer, nerves
By Kelly Kennedy
Tribune staff reporter
SourceJune 23, 2005
Jesse Sullivan lost both of his arms at the shoulders, but with the help of a prosthetic hand and a set of rewired nerves, he can now feel--and sense hot and cold--almost as if he had real fingers.
Two years ago, experts thought this advance in technology was at least a decade away. Now they see it as a leap forward in treating victims of stroke, lost limbs and paralysis.
Sullivan, 58, sees it as a step toward his fishing pole.
"That's where I'm going with it," Sullivan said at a news conference in downtown Chicago announcing the new technology. "And I think I'll be able to tie my own shoes."
Sullivan grinned as his doctor, Todd Kuiken, director of amputee programs at the Rehabilitation Institute of Chicago, showed a video of Sullivan using his prosthetic left hand to pick up eggs without breaking them. He could feel how tightly he held the eggs.
Of course, his setup is different from a typical person's. A lineman for a Tennessee power company, Sullivan in 2001 grabbed a high-tension wire carrying 7,400 volts of electricity, which incinerated his arms.
After the accident, Kuiken pulled out the four main nerves that used to connect to Sullivan's arms and fastened them just beneath the skin on his chest.
Sullivan's prosthesis has a computer in the forearm that is wired to a mechanical hand and to a "plunger" device on his chest. The hand sends signals up the wires to the plunger, which pushes the skin. That stimulates the nerves in his chest to transmit sensations to the brain as if the nerves were still connected to his real hand.
On Wednesday, when Kuiken touched a spot on Sullivan's chest, Sullivan said: "Oh, that's right between the finger and thumb on the back side of the hand."
If Kuiken touches one of Sullivan's prosthetic fingers, Sullivan can feel it and say which finger it is.
His brain doesn't register that the sensation comes from his chest. His brain interprets the signal as coming from the prosthetic hand.
"The first time I put this on, it was a feeling that's hard to explain," Sullivan said. "It lifts you up and gives you hope."
Kevin Englehart, associate director of the Institute of Biomedical Engineering in Fredericton, New Brunswick, said he invited Kuiken to be the keynote speaker at the Myoelectric Controls Symposium this summer because the research community sees his work as a breakthrough.
"When I realized what it could do, I thought, `This changes everything,'" Englehart said. "Todd's getting at the nerves that still contain information--information that normally would have been lost. He's really cheating, but in a good way."
Myoelectric refers to using electricity created in muscles to control outside electronic devices. In working with people who have lost whole limbs, doctors have been trying to figure out a way to control an elaborate prosthetic device with few remaining nerves and muscles.
"We hit a wall years ago, and Todd redefines the rules," Englehart said.
Sullivan made the news two years ago when Kuiken succeeded in transmitting brain signals to the prosthetic arm through the same nerves. Sullivan had only to think about moving his arm, and it moved.
However, to raise his arm straight in front of him, he had to either bend over and let gravity move it, or push it against a table, then hold it still for two seconds until it locked into place. That made simple tasks such as eating tedious, he said.
In the model introduced Wednesday, six motors, including humerus and wrist rotators, allow him to move his elbow, shoulder and hand at once: He can put his hat on in one movement just by thinking about it.
To demonstrate, Sullivan tried to pick up a water glass from a table. The first time, he dropped it. The second time, he wrapped his prosthetic fingers around it and picked it up, then set it back down.
"I just do it like you do," he said. "I have to concentrate on that glass, but I can do it."
The new prosthetic arm is still in the experimental stage, so Sullivan normally wears the device he must lock into place while eating, and that doesn't allow him to "feel." Kuiken hopes to have him using the new arm full time by the end of the year. So far, parts have cost about $100,000, but research and time have cost much more.
The institute recently received a grant from the National Institutes of Health to fit a female veteran from Arkansas with an arm system she can wear all the time, Kuiken said. He has already performed similar nerve-rewiring surgeries for three other people. Two succeeded, and one failed because the damage to the patient's nerves was too severe.
Wayne Lerner, president of the Rehabilitation Institute, announced at Wednesday's news conference a $5 million gift from the Searle Funds at the Chicago Community Trust to establish the Searle Program for Neurological Restoration. Institute researchers will use the funds to continue Kuiken's work.
They also hope to help patients control wheelchairs through brain/machine interface and to communicate by typing messages with thought. Kuiken said he wants to work on a prosthetic leg with motors and sensors that would allow amputees to "feel" when they take steps--something he sees as particularly timely for injured soldiers returning from Afghanistan and Iraq.
Sullivan sees it as timely for everyone in his situation.
"Nobody wants to be an amputee," he said. "The future is out there, and I'm looking forward to it."
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kkennedy@tribune.comCopyright © 2005, Chicago Tribune