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Motion Control
Kenny Whitten has Utah-made artificial forearms and hands, so there's no need to worry about him getting stung by the bee that he's holding.

Kenny Whitten can run a bulldozer and a backhoe. He cares for the cows on his land in Duncan, Okla., and when he has spare time, he likes to go fishing, hunting and skiing.

He's a good carpenter, a hard worker, a dedicated dad and grandpa.

Sometimes he seems like Superman. He can pluck a bee from the air and squish it without wincing. His hands are unbelievably strong.

But he can't tuck in his own shirt. It clings to him and comes right back out of the waistband of his jeans.

His left arm is artificial from above the elbow, the right from just below, the result of a serious electrical accident when he was working for a power company. He had climbed a pole and was helping move a line when a short a mile away sent a fireball down that line to him. He was 26, father of three very young children.

He comes from the Midwest, but his arms came from Utah, part of the state's long history of innovation in the field of bionics, man-made replacements for body parts that have failed.

Think artificial arm. Artificial heart. Artificial vision. Then think beyond that. Utah researchers have been designing, redesigning, perfecting and improving artificial body parts for decades. And they plan to do it until there's nothing left to do.

Utah has been home to bioengineering efforts dating back to the 1950s. And no single institution has been more involved than the University of Utah, which has put its imprint on much of the work being done worldwide, working closely with scientists both locally and around the globe.

Some of the work has already improved lives. In other cases, it's just beginning to hold real promise.

The beat goes on

Four years ago, Reid Clark was dying of heart failure. One of the founders of Novell, the once active, adventurous man had been grounded by his failing heart.

Dr. James W. Long implanted a Thoratec HeartMate left ventricular assist device (LVAD) as part of a clinical trial to see if a patient like Clark, too old to be eligible for a human heart transplant, could survive instead with the LVAD. Younger patients were already using it with the Food and Drug Administration's approval as a bridge to transplant.

The LVAD takes over the pumping function of the heart's left ventricle. It's implanted in the abdomen and connected to the heart, powered by a portable external battery carried in a fanny pack.

A little girl, Mikayla George, 10, of Herriman, spent six weeks on a biventricular assist device before receiving a heart transplant. The device itself is the equivalent of a total artificial heart. Its two small pumps pump at different rates to accommodate the needs of the two ventricles.

The devices are both similar and different. And if you traced back the innovation that created them, you'd find they both had some roots in the artificial organ for which Utah is most famous, the artificial heart, implanted in Seattle dentist Barney Clark in 1982.

The entire world watched, and you'd have had to live on the moon not to have heard of the University of Utah, where the technology was developed, or University Hospital, where the operation took place. It was a stunning medical first.

Barney Clark lived 112 days. Other hearts have been developed since the Jarvik 7 and, indeed, there were a number of lesser-known versions before the Jarvik-7. It was tradition that the person making significant design improvements or changes place his name on the device. Dr. Robert Jarvik, whose name adorned the artificial heart placed in Barney Clark's chest, left Utah not long after and has gone on to different heart designs.

Jarvik and other U. researchers designed the heart in the artificial organ program, led by another pioneer in salvaging body parts. Dr. Willem J. Kolff invented the first dialysis machine in Holland during World War II.

The ventricular-assist devices and other heart helpers that have been developed in the 21 years since that first artificial heart implant are descendants of that early heart technology.

"Utah has deep roots and contributed immensely to the early stages of the development of artificial heart technology," said Long, program director of LDS Hospital's Artificial Heart Program.

Looking back over two decades, though, Long said, "The launching as a permanent therapy in 1982 for Barney Clark was premature. Neither the technology nor the field was ready for this."

But it had to start somewhere.

"It has taken 20 years, improvement and better understanding on how to manage these patients to really get to a successful implementation of the technology. Only in the last decade have we been able to establish evidence it's an effective therapy."

The current LVAD technology keeps people who would otherwise die alive and provides a high quality of life. But it is, itself, terminal. Its parts wear out and it has to be replaced after a few years.

Companies, including one in Utah, are working on a next-generation solution. The Utah-designed HeartQuest device is nearing its final phase of preclinical trial testing. Within a decade, Long hopes the technology will be available in the operating room.

He said better outcomes are inevitable as doctors learn to reduce complications, as patients are allowed access to devices "when they are less wasted and therefore less risky" and as technology itself gets better. The machines themselves need to last longer, Long said, at least seven to 10 years.

The new design by HeartQuest has only one moving part and it doesn't touch anything. The rotor is suspended in a magnetic field, which should take care of wear and tear. The mechanical durability is virtually limitless. And electronics can be made highly reliable. Some components will be replaceable while the pump is still in place.

"There's a lot of promise and hope out there," Long said.

A helping hand

The Utah Arm was a U. baby, born in the Center for Biomedical Design (now the Center for Engineering Design). It was spun off to a company called Motion Control, created to manufacture it, which it began doing in 1981. By modern standards, it was brilliant but primitive. There was no simultaneous control of the hand, wrist and elbow. You'd run the elbow, lock it, then run the hand.

Two decades later, the most advanced generation of the arm is controlled by a microprocessor. It talks to a laptop, so you can plug it in to diagnose problems or make adjustments. It has an auto-calibration feature as well, said Ed Iversen, who was a member of the original design team at the U. and now leads Research and Development for Motion Control.

That lets the user adjust how easy it is to run. Over the course of the day, as the muscles tire, the user can turn up the power to the arm.

Dr. Harold Sears was a student member of the design team, which was headed by Dr. Stephen C. Jacobsen, considered the inventor of the Utah Arm. It really spawned two companies; the technology was sold to Motion Control, where Sears is now general manager. The other company, Sarcos (Jacobsen's there), has moved more into robotics. Occasionally, they work together on some new development.

Artificial arms can be electronic or mechanical. Mechanical devices tend to run on cables. For arms, the cable stretches across the individual's back. He swings the arm, then shrugs his shoulders to open and close the hand.

Electronics are a lot more expensive, delicate and capable. But the price tag can make the decision. Where a mechanical prosthesis can run from $8,000 to $25,000, being fitted with and learning to use an electronic arm may cost $60,000 to $100,000.

The Utah Arm and its progeny are decidedly electronic.

The most popular design for an electronic arm uses electromyographic signals from the "remnant muscles" still in place. When you flex a muscle in the body, it puts out a certain amount of electrical signal, and the stronger you flex, the more signal it sends. Someone who has lost an arm just above the elbow could use what's left of the bicep and tricep muscles, for instance.

There are other ways to move electronic arms, including position sensors, so shrugging a shoulder can trigger it. Or a force sensor, a metal piece that reads force across the shoulders. You can even press on a touchpad. Many people born without limbs have what's called a "vestigial finger," and the arm can be designed so that "finger" can run it inside the arm.

Initially, the challenge was creating components small enough but powerful enough to get the job done. These days, tiny off-the-shelf components are readily available. It's the evolution of technology. Early computer processors took up entire rooms. Now much more powerful processors fit easily in your hand.

The newest version of the Utah artificial arm, called the U3, is a dual computer system with two processor chips in the elbow, one to run the hand and the other the elbow. The advantage of the multiple-control device, unique to the U3, is it can control the hand and elbow at the same time.

Kevin Hays, electronic engineer at Motion Control, saw a powerful demonstration of that recently at Walter Reed Hospital, where many soldiers injured in Iraq have been fitted with new limbs.

Hays saw a patient pick up garbage with his artificial hand and arm. "He let his elbow down, then brought the elbow up and let his hand relax in one fluid motion. Jaws hit the floor to watch him do it. Normally, you'd bring it up, position it and wait to lock it in place."

But it's bittersweet, Hays said. For all the improvements over the past two decades, the technology does not yet exist to move individual fingers. He's not sure he'll see it in his lifetime.

Iversen said future improvements will likely be incremental. They're trying to make arms and hands that are quieter. And faster, without sacrificing strength. They dream of an arm that will be waterproof. It's marginally water resistant, so when he washes dishes, Whitten's careful not to fill the sink too full. He wears rubber gloves. He removes his arm to swim. Should he lose his footing and fall into the pool, it would be ruined.

"We want to make them more rugged, more shock-resistant, more reliable," Iversen said.

Motion Control is field-testing a system that provides feedback about force. It has a device that pushes on the user as hard as he's squeezing. It's not needed often, one user said, but there are times it would help. He worries when he's playing with his children. The hand squeezes with about 20 to 25 pounds pressure, something a human hand does not do.

That extra force is needed because the hand has no adaptable grab. Most people can grab something by cradling it, but a prosthetic hand has to squeeze, and that takes more strength.

There are many other companies building artificial arms. Otto Bock has mechanical and electronic devices, most for below-elbow amputees. Liberating Technologies has powered elbows, as does Hosmer, which makes most of the hooks in use. That's a sister company to Motion Control, both owned by Fillauer, which makes a partial hand.

It's true of all bionic innovation. The fields are crowded with different players, each building on collective knowledge. That's part of what makes it so exciting. It's competition, but it's also collaboration. And everyone's learning.

The eyes have it

Artificial vision is nowhere close to replacing the colors, textures and shapes lost to blindness. Though research in the field is thriving around the country, there are definite hurdles that must be overcome,

said Richard Normann, Ph.D, professor of bioengineering and ophthalmology at the U. Still, there's a sense of excitement and possibility regarding the evolving field of neuroprosthetics.

"What we're doing goes well beyond artificial vision," Normann said. "We're creating new ways to talk to and listen to the neurons of the central and peripheral nervous system."

Normann's efforts revolve around the "Utah Electrode Array," created in the mid- to late-'90s. Researchers in laboratories around the world are using this array, which contains 100 needle-shaped electrodes, each of which can talk simultaneously to many individual neurons of the brain.

The array is much smaller than a penny, and the 100 electrodes seem to hold endless possibilities. The arrays are marketed through a spin-off company formed by the U. called Cyberkinetics (formerly Bionic Technologies Inc.).

The Utah Electrode Array enables new therapeutic possibilities that were inconceivable two decades ago, Normann said.

Conventional surface electrode arrays are placed on the brain's surface over the areas they are supposed to stimulate. Dr. William Dobelle, a researcher in artificial vision, put surface electrodes over the visual part of the brain in blind subjects. When he passed currents through the electrodes, they could see points of light.

A group of California scientists are achieving similar results with blind subjects by placing surface electrodes on the retinas and stimulating them.

But though somewhat satisfying, such experiments reveal little that wasn't known back in the late '60 and '70s, Normann said.

Here's why: Surface electrodes are large, each about a millimeter in diameter. However, the neurons they're trying to stimulate are relatively small. These large electrodes can stimulate a lot of neurons at once and are not particularly selective.

That's a problem, because in the human sensory systems, natural stimuli evoke very focal sensory stimulation. "To try to replicate this with large surface electrodes might not be very effective," Normann said.

The Utah Electrode Array is different, designed to be inserted into the brain instead of sitting on its surface. The tips of these microelectrodes sit right next to just a few neurons. When small electrical currents are passed through the electrodes, they stimulate only those few neurons next to the tip.

That should result in two good things, Normann said: "The amount of current needed to stimulate neurons is 100 to 1,000 times smaller than required with surface electrodes, so the Utah Electrode Array should be safer and more biocompatible. These small currents excite only a small number of neurons in the brain, producing focal stimulation." This should produce stimulation closer to normal physiological stimulation.

Still, he said, there's a potential downside. Because the Utah Electrode Array is inserted into the brain or peripheral nervous system (which is home to extensive networks of blood vessels), researchers are working to ensure safety and to verify that they can implant the array into the brain without doing significant damage.

Hear ye, hear ye

Bioengineering researchers at the U. have a contract with the federal government for work with the auditory nerve, as well.

Cochlear implants can restore a sense of hearing to the deaf, but they're not perfect. The level of hearing that's restored with current cochlear implant technology varies. Some hearing-impaired patients hear spoken speech as soon as they turn it on. Many must work at it and practice, practice, practice. Even then, some patients don't do well, though just hearing a sound, like a car horn, can be helpful.

Normann's team is trying to implant the Utah Electrode Array directly into the auditory nerve, something they've been working on for almost three years with colleagues from the U.'s Otolaryngology Department. "We're trying to demonstrate efficacy and safety of what might be regarded as the next generation" cochlear implant.

An unproven but logical theory is that the Utah Electrode Array technology can more selectively stimulate auditory nerve fibers and may result in a higher fidelity restoration of speech, Normann said.

They're also going after the motor system with the Utah Electrode Array.

In certain motor neuron diseases, communication between the brain and the muscles stops and people become "locked in" in their own unresponsive bodies. That happens with ALS, Lou Gehrig's disease. It can also happen with severe high spinal cord injuries.

"We're trying to help these individuals using the same kinds of technologies. It's an ambitious project that may take years, even decades to develop fully," Normann predicts.

When you move your fingers on a computer keyboard, the command signals that cause your finger muscles to move originate in the motor part of the brain. The "little gray cells" fire in specific patterns that are translated to activity patterns that move down the spinal cord and send their message to motor neurons, causing specific muscles to contract. When the muscles contract, sensors in the muscles, joints and skin send the movement information back up the spinal cord to the brain.

A spinal cord injury stops that communication. The signals still begin their journey in the brain, but when they hit the injury, they stop and the muscles never get the signal. The sensory information is also blocked.

"Eventually, we want to fix all these problems. The first approach is to put the Utah Electrode Array into the motor part of the brain in order to record the muscle control signals, the commands that cause the muscles to move. These firing patterns could be used to control external devices, like a robotic arm or computer monitor or a wheelchair."

That kind of research is already under way at Brown University, Normann said.

Daniel McDonnall, a student in Normann's laboratory, is implanting the array in the sciatic nerve of animals and is achieving graceful control of the force in muscles by stimulating the motor nerves similar to the way they are normally stimulated. This work hinges on, among other things, ability to selectively stimulate these motor neurons, something only possible with high electrode-count arrays.

"We're just beginning to work on one small piece of this motor-control problem. It's an exciting application," Normann said.

"All of these technologies are in their infancy, and we're still in the earliest stages of research. There are many other applications we'd like to consider. What's really important is this technology is able to achieve highly selective stimulation of a large number of neurons. That's something not possible before. Medicine can capitalize on that."

Best to come

The quest to make a broken body whole again has taken many twists and turns. When bionic work began, no one had heard of gene therapy or stem cell research. There will, one day perhaps, be many solutions to that broken body's problems. But for now, replacement-part research goes on. In Utah alone, scientists and clinicians have grappled with not only those mentioned, but artificial lung, blood, blood vessels, joints, fallopian tubes, other limbs, kidneys, the pancreas and more. While they haven't designed all of them, they've been part of testing and fine-tuning them.

They all agree on one thing: Bionics is never better than the original human version, where fingers move independently, eyes see three dimensionally, legs can jump and the heart beats automatically.

But it's getting closer.

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