Question Of Mind Over Matter (Prosthetics; Prostheses)

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Question of Mind Over Matter

By Rachel Metz| Also by this reporter
02:00 AM Sep, 20, 2006

MIT assistant professor Hugh Herr is an advanced prosthetics researcher and a bilateral leg amputee, two conditions that have allowed him the rare experience of testing his gadgets on himself.

"You know how it feels when you're at the airport and you hit the moving walkway? It's kind of like that," he said of a new foot-ankle system he's developing with colleagues at MIT, Brown University and the VA Medical Center in Providence, Rhode Island.

The so-called biohybrid system sports a power pack and computer all contained within the prosthesis and uses sensors to allow more realistic movements than static, strap-on devices. The first systems have noninvasive sensors attached to the prostheses. In about two years scientists will implant sensors into study volunteers' nervous systems, Herr said.

"I've been an engineer-designer for a long time, but this is the first system (from which) I can benefit personally," he said. "It's kind of fun. I don't know why I waited this long."

Herr's enthusiasm is perhaps understandable, given his disability. But, in light of the immense strides scientists have achieved in prosthetics in the past decade, it is also well grounded. Improvements in materials for comfort and performance are part of the story. Of equal significance, scientists are probing the limits of mind-body interaction, developing tools that use artificial intelligence, muscle and neuron sensors -- and even plugging directly into the brain -- to achieve unprecedented results. Some patients need only to think to make a machine do their bidding.

The aggressiveness of the research has taken some people aback. "I would look under the hood and make sure the technology is as developed and is as good as they say it is," said Andrew Imparato, president and CEO of the American Association of People with Disabilities.

Even so, he added, further research could yield enormous benefits. "I think there's a lot about the human brain we don't fully comprehend. So if scientists are tapping into the brain to let people do things we haven't been able to do before, that's exciting," he said.

A breakthough could transform the lives of millions of people. The Amputee Coalition of America estimates between 1.8 and 1.9 million people in the United States live with some type of limb loss.

So just how close are we to a seamless blending of man and machine? In this four-part series, we take a look at some of the most promising -- and astonishing -- recent developments, from cutting-edge research labs to do-it-yourself garage mechanics that are changing our ideas of the body and its boundaries.

The Bionic Arm

In 2001, Jesse Sullivan, a high-power lineman, was nearly electrocuted and so badly injured that doctors had to amputate both of his arms. In 2002, he became the poster boy for the bionic arm when he appeared on national television wielding a computerized, biohybrid arm created by scientists at the Rehabilitation Institute of Chicago. On Thursday, Sullivan and the first woman to test the bionic arm, Claudia Mitchell, demonstrated their new abilities with the arm. Sullivan told reporters he can now trim hedges and mow the lawn. Mitchell, who lost her arm in a motorcycle accident, said the arm allows her to carry a laundry basket and fold clothes.

The researchers implant sensors within the pectoral muscles, attaching them to nerves that controlled elbows, wrists and hands before the amputations. The arm takes advantage of the fact that the brain can imagine moving an arm that isn't there -- a sometimes-unwelcome phenomenon for amputees known as "phantom arm" that can even involve pain in the missing limb.

Since the brain is still sending signals to the arm, the device can hijack messages telling muscles to move, or to feel touch or temperature. The researchers attach sensors from the device to the nerves, which attach and become intertwined with the nerves over time as the patient thinks about moving the arm.

When the prosthesis is strapped on, electrodes line up with the sensors to control the computer and motors in the bionic arm to operate the hand -- and all the user has to do is think.

The rewiring can causes minor side effects: "If you touch Jesse on his chest in certain places, he can feel it like it's his hand," said Todd Kuiken, director of the institute's Neural Engineering Center for Artificial Limbs, which developed the technology.

Five more amputees, including Mitchell, are now testing biohybrid arms. In the lab they use fancier arms with six motors, while the take-home version has three. Four of the volunteers are unilateral amputees, while one, like Jesse, has lost both limbs. All have received nerve implants, and the system is working for all but one patient, Kuiken said. The National Institutes of Health has provided $2 million of the $3 million Kuiken's lab has spent developing the arm.

A bionic leg is next on Kuiken's to-do list -- as prosthetic companies develop motorized legs, Kuiken hopes to adapt his technology to control them.

The Mind Reader

Cyberkinetics' brain-computer interface, BrainGate, is a breakthrough device for people with spinal cord injuries. Plugged directly into the brain, the device allows paralyzed people to control a computer, flip switches and move a robotic hand -- by simply thinking.

Matthew Nagle, who was paralyzed from the neck down after being stabbed in 2002, was the first patient to try BrainGate. Sitting in a wheelchair with a plug protruding from his head he amazed everyone who saw him control a computer cursor or beat them at Pong.

Cyberkinetics scientists now say that BrainGate can even pick up brain signals from "locked-in" patients who are completely without movement or speech.

"They're desperate to communicate," said Cyberkinetics CEO Tim Surgenor.

The researchers recorded cortical activity from an ALS (Lou Gehrig's disease) patient. Another study volunteer who can't speak after a brainstem stroke used the BrainGate to type.

The brain implant sends signals to an external amplifier, which sends the messages through software that generates cursor movements or other electronic activity. The test system is wired, but the company's scientists say the final product will be wireless.

Surgenor hopes BrainGate will be FDA-approved in about four years.

The Second Sight
Blind patients were granted sight earlier this year in exchange for participating in a clinical trial testing a wireless retinal implant.

Researchers at Intelligent Medical Implants and IIP-Technologies in Europe created the Learning Retinal Implant System with hopes of returning sight to patients with damaged retinas. They successfully tested the device on four patients rendered blind by retinitis pigmentosa -- a disease that causes degeneration of the retina and leads to complete blindness in just a few years for one-third of those diagnosed. It affects 1 million people worldwide.

"If you talk to those people, even one single dot makes a difference," said Hans-Gurgen Tiedtke, CEO of IIP-Technologies.

The system includes glasses featuring a wireless transmitter and a mini-camera to pick up images. The glasses connect by cable to a processor pack worn at the waist that analyzes the information like a retina would, then send the image information to a chip implanted in the retina. The chip electrically stimulates the retina so ganglion cells can pick up the images. From there, the process continues like it would in a healthy eye: the information goes to the optic nerve, then to the brain and visual cortex where the information is reassembled as a picture.

It won't restore 20/20 vision, but researchers hope patients can eventually identify doors, chairs and windows, Tiedtke said, and perhaps even pick out faces.

The study volunteers received a beta version of the system. The companies plan to launch a second clinical trial with an updated version of the technology by the end of September. Tiedtke hopes the device will be commercially available in Europe in 2008, and in the United States soon afterwards.

The Universal Prosthetic for Kids
Adults can often use one prosthetic for years. But children are constantly growing, meaning their prosthetics must be replaced as often as every six months. So Tom Chau, a scientist at Bloorview Kids Rehab in Toronto, is developing a control system that will remain a constant link between the child and the prosthetic. It will adapt to growing boys and girls, and attach to various sizes of prosthetic hands.

"Part of the solution to this problem of the child being so dynamic is you need to be able to recycle some of these components," Chau said.

Chau's system uses silicone-encased sensors with microphones that capture muscle noises. A microcontroller in the prosthetic filters out background noise and determines how the hand should move.

The prosthesis could help children participate even in high-energy activities because sweat won't interfere with the sensors, Chau said. It could even be waterproofed for swimmers.

He's first testing prototypes on adults because they generate stronger muscle signals, which makes it easier to test. Plus, they can sit still longer.

The High-Tech Knee
South Africa's Oscar Pistorius set a world record this month in the 200-meter dash at the 2006 Paralympic Athletics World Championship, using specialized "blades" to clock a time of 21.66 seconds -- fast enough to best the men's Olympic gold medal time of 22 seconds flat in 1920.

If it's exciting to watch athletes compete in running events using slick, custom prostheses, in reality such devices are more useful in a competitive sprint than getting around the house.

Bethesda, Maryland-based Hanger Orthopedic Group has helped many amputees excel athletically with high-tech prostheses. But they're also helping people with more mundane but equally important activities like walking to the bus stop or feeding themselves.

And just because the tasks are more pedestrian doesn't mean the scientists are skimping on technology. The Power Knee, for example, uses artificial intelligence to help amputees walk, get out of chairs and clear steps more naturally. The knee has motor-driven power, and an ankle sensor. On the patient's functional leg, the user wears a computerized shoe insole, which communicates with the prosthesis.

"For the first time, your left and your right foot are working together in unison. It gives you a much more stable, much more natural gait," said Dale Berry, Hanger's vice president of clinical operations. It also reduces stress on the body.

The knee system became available earlier this year for $100,000. Some customers might experience sticker shock since prosthetics that use hydraulics cost $20,000. But Berry thinks customers will be willing to pay for the improved gait.

Hanger is also working with Ossur to create a foot-ankle device that automatically adjusts to heights whether the user is walking barefoot or wearing a 1.5-inch heel. It should use less energy and look more natural than other devices, Berry said. "No other prosthetic foot can do this."

http://www.wired.com/news/technology/me ... 785-0.html

 

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Give 'em a (Working) Hand


By Quinn Norton| Also by this reporter
02:00 AM Sep, 21, 2006

Like most good open-source developers, Iraq war veteran Jonathan Kuniholm started off scratching his own itch.

Kuniholm was a graduate student in biomedical engineering at Duke University, and the cofounder of a small industrial design firm, when his Marine reserve unit was called up for service. He was shipped off to western Iraq, where, a few months into his tour, he fell victim to an IED -- blown down while on foot patrol near Haditha Dam.

The man beside him was fatally injured. Kuniholm sat up. "The first thing I noticed was that my arm was pretty seriously injured, my hand was mostly severed.... And then I noticed that my gun was broken in half."

Motor Heads
The New Bionics
The prosthetics of the not-so-distant future are intertwined with muscles, nerves … even neurons. By Rachel Metz.

Interactive Bionics Tour:
See applied prosthetics research in action.
DIY Prosthetics
Amputees who can't find the right prosthetics on the market build their own -- sometimes out of Legos. By Quinn Norton. [ You are here ]

Grow Your Own Limbs
Scientists are learning how amputees might eschew the prosthetic and grow back missing limbs. By Kristen Philipkoski. [ Coming Sep 22 ]

I Want My Bionics
What if bionics get so good that we want them even if we don't need them? By Chris Oakes. [ Coming Sep 25 ]

After escaping an ambush with the help of his companions, Kuniholm was taken back to America. Following months of surgery and rehabilitation, he found himself at Walter Reed being fitted for his first prosthetic arm -- a myoelectric limb that looked and felt like a smooth plastic doll's hand.

He was not impressed. The design was relatively advanced for a prosthetic, and represented a cosmetic improvement over the traditional hook design. But it was slow to operate, and not strong enough to hold a fork or open a door. Handling a soldering iron would be out of the question.

But as a dismayed Kuniholm recovered in the hospital, his engineering colleagues at Tackle Design in Durham, North Carolina were already exploring his options.

Kuniholm founded Tackle -- an industrial design skunkworks -- with several fellow students in 2003. Now his partners were determined to find the best technology to replace his lost limb. What they found was this: The best simply wasn't very good. "We were very disappointed with what was out there," says Tackle partner Jesse Crossen.

The majority of people using upper limb prosthetics still use a basic hook design that hasn't seen much progress since 1912. And the so-called "state of the art" upper limb prosthetics, while cosmetically advanced, are still based on 50-year-old technology, and are barely useful.

The prosthetics are activated by muscle signals read from the skin surface of the remaining limb, but offer few actions, have little strength, and require a battery. They are often slow to respond. As a result, very few amputees use them for very long, and half of those with upper limb loss use nothing at all, estimates Kuniholm.

When Kuniholm got out of the hospital, he and his partners decided they'd have to improve the state of the art themselves. "We knew that for years to come we'd be working on prosthetics," says partner Chuck Messer. The next question was, what would they do with the resulting intellectual property?

"We realized if we don't open our designs up they are going to languish on Jon's arm," says Crossen.

And with that, the first open-source prosthetics community was born.

Founded last year, the nonprofit Open Prosthetics Project applies the ethical and intellectual property foundation of open-source software to the task of building better artificial limbs. The project releases its experimental designs to its website in the public domain, free for anyone to use, forever. Anyone can download the STL files, tinker with them in CAD software, and submit them to a rapid manufacturer, such as a prototyping 3-D printing company.

This lets anyone turn out a customized prosthetic device without incurring tens of thousands of dollars in production costs. A user with a few hundred dollars to spend can be holding the physical reality within a week, though the post processing would still require some expertise.

"You have to drill screw holes and tap the threads yourself before a prosthetic would be usable," says Kuniholm.

So far, the project has produced a handful of useful homebrew prosthetic hacks, and is closing in on a solution that would dramatically improve the functionality of the common hook device.

The standard hook today comes in two basic types. In one, the metal hook is closed normally, and you shrug your shoulder to open it, maintaining the shrug as long as you want it open. The other type is normally open, and you shrug to hold it closed.

Open Prosthetics' experimental design incorporates both modes in one hook, using a pin/spring/cam set-up controlled by the intensity of the wearer's shrug: A limited shrug momentarily opens or closes the hook, just like the traditional design, while a full shrug acts as a toggle, reversing the hook from open to closed, or visa versa, and leaving it there until the next actuation.

They've built and rebuilt two versions of this positional hook, and they have a working prototype of the entire limb made from LEGO Technic parts. (This video demonstrates the strength difference of the two modes in picking up a small object.)

Another design in development would eliminate the mechanical hook altogether, replacing it with a realistic vacuum-actuated hand that can curl tight around a graspable object. (video)

Other Open Prosthetics innovations are do-it-yourself projects and simple hacks that, while less ambitious, are no less important. One of these was contributed by Robert Haag, an IT salesman from Atlanta, whose son Michael was born with an unformed left hand.

The first problem Haag encountered was getting Michael, now 2-years old, to understand what his prosthetic was for. "Michael is too young to train," says Haag. "Everything is done with play."

But his son didn't notice when he was opening and closing the prosthetic, and couldn't concentrate enough to use it. Haag found himself frustrated by the dearth of solutions available from existing technologies and techniques. "I wanted to jump in there and start doing something about it instead of just waiting for someone to solve the problem," Haag says.

He first devised a system to play a sound clip when his son opened the hook on his arm, and another when he closed it. But without an engineering background, Haag found himself blocked at interfacing the electronics with the arm.

He went back to the garage with a Dremel in hand, and, taking a different approach, converted a child's Spider-Man fishing pole into a replacement terminal device -- the modular part of a prosthetic that screws into a mount on the remaining portion of the limb.

The hardware hack was successful. Michael could cast his fishing hook out, Haag would attach a toy, and Michael could reel it back in. (video) For the first time, his son was engaged and doing more with a prosthetic than he could on his own.

Haag posted instructions for building the fishing rod terminal device on the Open Prosthetics website, as well as the plans for his incomplete audio trainer, which he hopes someone else will bring to fruition. "I'm out to help my son," he says, "and anyone like him."

Such DIY solutions are as much a part of Open Prosthetics as its polished design plans, and the project has started to feature instruction on how to build prosthetics out of supplies you can get at the local Fry's or WalMart.

It's trying to unite a demographic that's been left behind by market economics, says Kuniholm. "Everybody who deals with these issues have been solving (these problems) in their own little world. We want to create a true community."

As of 1996, the last year anyone counted, there were an estimated 1.2 million people in America living with limb loss, according to the National Center for Health Statistics. But more than 90 percent of these were missing legs or feet, not hands, estimates the Amputee Coalition of America.

The Iraq war and stories like Kuniholm's -- solders saved by body armor at the cost of an extremity -- will push up the number of upper limb amputees, but by far the biggest cause of limb loss remains foot amputation in advanced diabetes. "The average amputee in America is over 50, not very active, and looking for a foot," says Kuniholm.

That means most R&D money in prosthetics goes to feet. Open collaboration can help fill that gap, and it's particularly well suited for upper limb prosthetics. People expect their hands to serve them in highly individualistic ways. A rock climber, a knitter, a farmer and a typist don't really have the same hands. Right now, they can't hope for one prosthetic to suit each situation or aesthetic.

Kuniholm clearly doesn't want that moment outside Haditha to define him or his work. The motivation to open his prosthetic designs is partly about building community and creating an environment for iterative design, but it's also partly about enlisting the power of many eyes and minds to build better hands, so that he doesn't have to devote his life and business to doing it all himself.

"I didn't feel like only dealing with this problem," says Kuniholm.

As for Haag, it was one morning in his bathroom that he really understood what he wanted for his son, and it wasn't something government grants or medical companies were ever going to give him. He was looking at his toothbrush, a piece of curved space-age plastic, covered with racing stripes and stylish grooves.

He realized that as a society, we've made toothbrushes cool. "I'm looking at my toothbrush, and I'm looking at his limb, and looking back at my toothbrush ... why can't we make this limb as cool as this toothbrush?"

These days he doesn't fantasize about a realistic looking hand for Michael. He tends to think about brushed stainless steel, or flame streaks embedded in clear plastic. He wants the other kids on the schoolyard to look at his son's helping hand, and say, "Wow, I want one of those!"

Kuniholm agrees. His work won't be done until he's made "something that's so cool, somebody with two arms would want an amputation to get one."

http://www.wired.com/news/technology/1,71797-0.html

 

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What if Bionics Were Better

By Chris Oakes| Also by this reporter
02:00 AM Sep, 25, 2006

Phillipa Garner is a self-described "gender-hacker."

In 1993 at the age of 51, she underwent sex reassignment surgery. That was just the beginning of her quest for self-improvement. She followed the sex change with more modification: vaginoplasty, brow reduction, cheek implants, breast implants, lip augmentation and a face-lift. And she'd happily sign up for more, she says.

"I would be inclined to go through with some pretty radical conceptual self-improvement procedures," Garner said. "I think of cosmetic surgery as collaborative art.... And when I next have disposable income, I'll be back in the O.R."

Garner is part of a tiny population of early adopters eager to test bionics by choice rather than out of need. Any company that comes out with, say, a bio implant for Wi-Fi connectivity or devices that interact directly with the brain, can put Garner on the waiting list, she said.

I Want My Bionics
What if bionics improve so much we want them even if we don't need them? By Chris Oakes. (You are here.) Such desire for radical body transformation remains very much on the fringe, and represents behavior that many if not most people would consider taboo. But the distance between denial and acceptance could turn as much on what current machines can and can't do, as it does body image.

In science fiction, advanced bionics that not only replace but surpass human potential are often treated as a given. Although today's technologies come nowhere close to that ideal, it's increasingly tantalizing to ponder what-if scenarios.

To Garner, surgical enhancements fall right in line with her vocation. A freelance illustrator whose work includes monthly satire in Car & Driver magazine based on cheekily modified car concepts, she has also produced a stream of personal vehicle designs for more efficient transport of the human body.

Whether she's modifiying vehicles or her own body, it's all part of the same quest for improvement.

"I felt that my situation in general was screaming out for a monkey wrench in the works," she said. Will the day arrive when she might swap her legs for some that can attach directly to one of her modified vehicles? Scientists say the technology isn't there yet -- and Garner may have quite a while to wait.

Control and reliability is a necessity in limb design. Researchers working on prosthetic limbs say the devices must be flawless before they can be seen as a desirable replacement to a biological arm or leg.

"If you try to replace something on the human body, you have to do it in the way that the individual will feel exactly that they have the full control of the mechanism," said Stephane Bedard, founder and chief operating officer of Quebec-based Victhom Human Bionics.

Victhom's Neurostep technology is in clinical trials. Components are implanted in a limb that has suffered nerve damage -- the device detects normal nerve signals sent to move a muscle or joint, then relays them electronically to the target muscle. The goal is for the patient to regain abilities like flexing joints, balance and stability of movement. Even such sophisticated technology, however, won't get much use if it's not convenient, experts say.

"Give a person an absolute state-of-the-art prosthetic limb with all the robotics technology we have and all the sensors we have and see if they're still using it in six months," said biomedical engineer and neuroscientist James Patton. "Most of them don't even put it on in the morning."

Patton works in the Robotics Lab at the Sensory Motor Performance Program of the Rehabilitation Institute of Chicago. Patton said amputees often choose simpler prosthetics that emphasize realistic appearance over function -- or the plain old "hook" -- because they get more done with it.

One accidental poke in the eye is a deal-breaker for anyone trying a prosthetic. Any malfunction destroys a user's trust, Patton said.

And unless a prosthetic performs even better than a natural-born limb, it's not likely able-bodied customers will be lining up.

"If one day a bionic hand outperformed a biological hand just on sheer practical performance -- like dexterity, strength and speed -- I'd probably consider replacing my biological hand," said Kyle Peterson, a 21-year-old information science major at the University of North Florida in an e-mail.

A technology enthusiast in general, Peterson's imagination regarding prosthetic possibilities was first fostered by the development of the Cyberhand. In November 2005, European scientists presented their prototype Cyberhand. The user could feel and touch, as well as make the hand grasp and move in response to their own nerve signals. Nerves in the wearer's arm fire an intricate package of touch and temperature sensors, motors, articulated joints and controls.

The Cyberhand was designed for amputees. But the prototype caught the attention of imaginative gadget freaks. Some, including Peterson, have mused over whether they might ever consider buying their own. But first, he'd want a safety guarantee. "No crushing babies or poking my eyes out when trying to put in my contacts," he said.

Body-modification enthusiast Garner said she is more compelled by implanted communications or entertainment technology. "I'd like to turn myself on via a TV-style remote or perhaps a tongue-operated keypad in the roof of my mouth."

Inventor and author Ray Kurzweil, author of The Singularity Is Near: When Humans Transcend Biology, is an optimistic visionary when it comes to the potential for the human body to intertwine completely with technology. But he doesn't downplay the difficulties involved. "People find it daunting ... we're not going to get there in a single leap."

Other futurists agree. When looking forward at radical leaps in medicine and technology, there is sometimes a tendency to draw stark visions of radical change and to imagine crossing them in ways that seem unappealing from today's perspective. Imagining the line between needing and wanting these technologies is to forget how change happens, some researchers say.

"I don't think it's possible to create a distinction between need and want," said Steve Mann, a pioneer in wearable computing technology and electrical and computer engineering professor at the University of Toronto. "Do we really need clothing? It's hard to say," Mann said. "It becomes a technology that receives widespread acceptance because it provides a mixture of need and want."

Some of Mann's donnable devices creep toward early bionic-like complements, if not replacements, to human function. His wearable EyeTap is an always-on eye-cam that has been adapted for control via signals sent from the wearer's occipital lobe.

Nonetheless, whether people will want to surrender their natural limbs when they don't need to may be another story. Dr. Henrik Christensen, a professor at the Royal Institute of Technology in Stockholm, is on the steering committee of the Neurobotics project. The European Commission-sponsored initiative is led by Paolo Dario, the Italian researcher who also led the Cyberhand team.

Christensen said scientists can build in technical safeguards, such as the Neurobotics projects standards to secure human-to-machine communications -- and prevent devices from being taken over maliciously, one ominous possibility. But some of the bigger questions of societal acceptance and rejection of man-machine convergence will certainly be influenced by society itself.

Kurzweil says the vision of permanence is incorrect, anyway. Invasive, permanent bionics are unlikely to be humanity's path into a bionic future. "Temporariness really changes the equation," Kurzweil said. "I think people will be hesitant to make an irreversible decision, unless there are very compelling advantages."

Temporariness was in fact the critical factor for Paris-based Brenda Nahon, another conventional example of a person who chose cosmetic surgical change because she simply wanted it: breast implants. As she pondered the operation, it was the possibility of later having the implants removed that clinched the deal.

"To me, it wasn't a permanent thing -- even though it will be permanent," Nahon said. "I knew that if I didn't like it, I could go back to what I was."

Nahon's plastic surgeon, Dr. Pierre Nahon (also Nahon's brother-in-law) is rigorous about making sure a patient understands the psychological as well as physical impact of cosmetic surgery. Too many operations are performed, he said, without the doctor and patient being aware of the risks.

Nahon believes the questions will be the same when it comes to tomorrow's more advanced surgeries.

"Sometimes you do a very nice operation, but the patient was not expecting the psychological effects," Nahon said.

http://www.wired.com/news/technology/1,71840-0.html