Tuesday, March 15, 2011

New bionic hand gives Montana man more dexterity

From The Daily Inter Lake in Montana:

Over the last eight months, Bill Corrigan of Polson has learned how much he took his hands for granted.

While working a second job at a restaurant, he caught his left hand in a meat grinder, destroying four fingers and leaving his thumb hanging by a thin bit of ligament and nerves.

“My thumb was medically severed,” Corrigan said. “It was reattached, and I have some movement.” Luckily he was right-hand dominant but actually used both hands for many of his daily activities. Corrigan, 30, quickly learned just how many as he fumbled through everyday tasks such as cooking and dressing with just one fully functioning hand.

“It was really frustrating,” he said. “You don’t really realize what you’ve got until it’s gone.”

But last week, Corrigan, a floor manager for the Polson Walmart, was on his way to regaining some of that dexterity. He stacked cones and picked up small balls and even a package of Skittles with his left hand using his reattached thumb and four prosthetic fingers.

“I had been wondering about the sensation or feeling,” he said about picking up objects. “It’s almost like you do feel it.”

Corrigan was working with his prostheticist Doug Jack of Northern Care in Kalispell and Karl Lindborg, a specialist in myoelectric prostheses. He was near the end of an all-day fitting and training session with a prototype of a high-tech device called ProDigits made by Touch Bionics.

“He’s doing exceptionally well,” Jack said.

When Corrigan receives his custom-fitted prosthesis, he becomes one of just 40 people in the United States using the lifelike fingers powered by tiny motors. Most amazingly, he controls the fingers with his own muscles routed through a programmed microchip to bend, touch and pick up objects like a natural hand.

Through myelectic (skin) testing, Lindborg selected a pinky finger muscle, which Corrigan once used to spread his little finger, to close the bionic fingers. Large muscles that turn his hand to the right open the fingers.

By tensing a chosen muscle for two seconds, he invokes other modes, like pointing one finger.

“When we tense our muscles, there’s a little micro voltage on the skin surface,” Jack said.

Electrodes precisely embedded in a silicone glove (socket) sense the micro-volts from muscles, powering up the motors in the articulating fingers. Lindborg said that, with repetition, the brain learns the new routines so they become almost automatic.

“In just one day, he’s learning to do it,” Jack said.

Jack and Lindborg function as a team that includes occupational therapist Tim Tracy of Tracy Hand & Occupational Therapy in Kalispell. The three continue to work with Corrigan to tweak the prototype’s fit and help him master his muscle movements to operate its several modes.

“The challenge is to see if we have the best angulation to provide a functional grip,” Lindborg said, as he made adjustments to the knuckle area of the prototype.

On an earlier trip to Kalispell, Lindborg assessed what remained of Corrigan’s left hand and deemed him a good candidate for ProDigits created by Touch Bionics in 2009. Before 2009, powered hands were available only to patients with complete amputations.

“We’re the first ones on the block” with a power solution for partial amputees, Lindborg said.

To collaborate with Touch Bionics, Jack had to meet a list of qualifications, including understanding advanced technology, willingness to work collaboratively with an occupational therapist and working in an ABC Certified prosthetics facility. Jack said he welcomed the assistance with the ProDigits device.

“I could try to go about fitting this myself, but it’s in the best interest of the patient to bring in experts who do this all the time,” he said. “A lot hinges on this for Bill. He’s depending on me not to do a quick and dirty fit.”

As Corrigan worked stacking cones and picking up balls, Lindborg made adjustments to the microchip remotely through Bluetooth technology in his laptop. Graphs provided a visual display as electrodes picked up Corrigan’s muscle movements.

Corrigan’s wife, Tracee, and his friend Kyle Stinger were at his side for moral support. As he mastered moves, Corrigan relaxed and began to have fun with the exercises.

“Typically, the feeling they get is, ‘This is doable,’” Jack said. “To see the look on their face as they realize, ‘This can work,’ is so rewarding.”

In about two weeks, Jack and Corrigan will travel to California for the final step, when Corrigan receives his custom-made ProDigits. Jack said he will take a three-day boot camp in the operation of the device so he can provide follow-up care as well as learn for future patients.

According to Lindborg, many more people could benefit from ProDigits.

“There are more partial hands than upper and lower limb amputees combined,” he said.

At between $65,000 and $70,000, price might present an obstacle for those without private or government insurance coverage. But the life-changing potential for patients is priceless.

Corrigan said he didn’t know where to start with the change ProDigits will make in his life.

“Cooking for one thing — grabbing a pan instead of chasing it. Dressing, grabbing a drink of water,” he said. “This is going to be awesome.”

Although he could choose a lifelike hand, even tattooed, for the final prosthesis, Corrigan was leaning toward choosing a basic black for his. The company even offers futuristic-looking versions, like one a patient had infused with a spider web.

“I wouldn’t care if it was bright pink,” he said with a laugh. “Just as long as I have the function of it.”