THE GIFT OF ONESELF

Losing a hand is akin to losing a family member, one volunteer told Clark. “Emotionally, to get back the sense that their hand is actually alive again—which is something we can begin to do—is very, very meaningful to them,” Clark says.

“If we can give them some sensation, then they start to feel it’s theirs and they’ll use it,” adds Hutchinson.

With each volunteer, each piece of the puzzle, Clark and his team get ever closer to reuniting people with, in some senses at least, their own hand, although it’s far more than that. “I want people to have their sense of self restored, to feel whole again,” Clark says.

In 2015, the U received the ﬁrst part of a $4.8 million federal grant that funded the most recent round of testing, carrying the neural interface program from virtual reality to volunteers testing a wireless arm both in the lab and on campus grounds. The involvement of U amputation rehabilitation specialist Christopher Duncan focused in part on “taking them from basic science, watching a computerized hand on a screen moving through a range of motions, to real space.” He began by printing 3-D open-source hands and implanting sensors that meant volunteers could start to control the prosthetics with their thoughts. These accomplishments were a bridge to the LUKE hand, says Clark. The team has high hopes for the impact of the HAPTIX program. Duncan recalls how one double-amputee hadn’t felt anything with his hands in 20 years.

The volunteer had withdrawn from society to a nocturnal life of video games, which he played with his toes. But as he spent more time at the lab, “we saw him blossom,” says Duncan. “He was positively ecstatic he could feel things.”

HOLDING HANDS

As Keven Walgamott talks about the accident that claimed his left hand, he repeatedly massages the end of his arm where the hand was amputated. The Twin Falls, Idaho-born realtor was pulling a submersible pump out of a 20-foot well on his property when an arc of electricity from overhead high voltage lines struck his pole as he raised it. The electricity went in through his left hand, through his body, blew half his left foot off, and knocked him unconscious.

His prosthetist recommended him for Clark’s studies. “I thought it would be helpful if they could improve the prosthesis,” Walgamott says. “I don’t wear one now because it’s so impractical.”

After Hutchinson implanted several arrays of electrodes into the nerves and muscles in his forearm that help control the hand and wrist, Walgamott underwent tests in Clark’s lab. His amputated left arm was hidden on one side of a small barricade, but he was able to control one of Duncan’s 3-D printed hands, which was in front of him.

Once the experiments for the day concluded, Suzanne Wendleken, a student researcher, asked Walgamott if there was anything he’d like to do. “I’d like to clasp my hands together,” he said.

Clark’s ears pricked up. Not clasp the prosthetic—but “my hands.” Walgamott reached out with his intact biological hand and gripped the prosthetic. “I really felt like it was my hand,” he recalls. “For a split second, it was remarkable to be able to clasp hands again.” In the second half of Walgamott’s 14 months with the lab, the team brought in the LUKE arm and conducted the tests all over again, but this time with the more advanced LUKE arm electrically connected to Walgamott’s motor and sensory systems. He was the ﬁrst person to try the sensorized LUKE arm this way. “Not only did it move, but I felt things when I touched them, too. I hadn’t felt anything on my hand in 12 years,” he says. Walgamott turned to his wife, and she took his left hand—his LUKE hand—and shook it. Perhaps more than any other volunteer, he highlighted that “what you do when you love somebody, you touch them,” adds Duncan.

ON THE CHOPPING BLOCK

Perry Pezzarossi’s contribution to HAPTIX began in late August 2017, when his primary doctor in Louisiana referred him to U of U Health to ﬁnd an answer to the chronic pain in his right hand. For many years, since shattering his wrist in 1993 on active service, he had been forced to live with excruciating pain. He faced one solution, albeit not one he wanted to act on: amputation. Pezzarossi met with Clark, and the researchers connected the LUKE arm to him.

His wife handed a ball to the LUKE hand, and Pezzarossi tossed it back to her with his thoughts—even though his biological hand couldn’t move because of his shattered wrist. “That’s it,” he said. “Chop and swap. I’m in.” Because he lived out of state, U researchers hadn’t been considering Pezzarossi as a possible test subject. In addition, unlike the six previous volunteers who had lost their hands a decade or more before their involvement, Pezzarossi still had to go through the removal of his damaged hand before he could participate. “If I prevent one person going through what I have, then I win,” he says.

Hutchinson amputated Pezzarossi’s right hand to help reduce his chronic pain and make it possible to attach a conventional prosthetic arm. He implanted three electrode arrays in Pezzarossi’s arm nerves and 32 electrodes in his remaining forearm muscles. Pezzarossi’s long disuse of his broken, twisted hand, its aberrant movements (called dystonia), and arm-muscle atrophy all raised questions for the research team about how soon he would be able to control the arm post-surgery. They needn’t have worried. “He was very successful, right off the bat,” Clark says, controlling up to 16 different ﬂexion and extension movements of a virtual arm.