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January 27, 2003

Working towards the 'Six Million Dollar Man'

From: Toronto Star, Canada - 27 Jan 2003


We can rebuild him. We have the technology. We have the capability to make the world's first bionic man.

— Intro, The Six Million Dollar Man

In the popular 1970s television series, actor Lee Majors played Col. Steve Austin, an astronaut and NASA test pilot horribly injured in a plane crash.

He survived and was fitted with $6 million worth of bionic parts — an arm, an eye and both legs — which give him super-human strength and speed. Austin's love interest, Jaime Sommers, has suffered a sky-diving accident and been similarly refitted with two new legs, an arm and a bionic ear.

Thirty years after The Six Million Dollar Man made its television debut, researchers are still struggling to design body parts that are faster and stronger than their biological originals.

In most cases, after expenditures far exceeding $6 million, replacement parts still can't match ordinary human capability. But major strides have been made in bionic research and many people are enjoying the results.

Prosthetic limbs with downloadable software now assist with mobility and dexterity. Implants help the deaf to hear again. And many blind people can now see with the aid of microchips and video cameras connected to the brain.

Optobionics Corp. of Naperville, Ill., is developing a silicon retina implant as a way to treat retinitis pigmentosa, a disease in which the retina's sensory cells deteriorate, gradually causing blindness.

A microchip with 5,000 microscopic solar cells is implanted in the retina so that it's in direct contact with the diseased area. When light strikes one of the light sensitive components, the chip sends an electrical signal to the damaged (but still functional) retinal cells.

"It's not a case of throwing a switch and now they are better," says David McComb, Optobionics director of public relations.

But he says the six people with the artificial silicon retina implants are doing well and most are reporting significantly improved vision. And while the company had originally expected that only those cells directly in contact with the chip would be affected, there is some evidence that cells near the chip are also improving.

Unfortunately, not all blind people can be treated with the device. Much depends on the cause of blindness and what parts of the eye are still functional.

In Lisbon, Portugal, the Dobelle Institute has made a vision system that circumvents the eye altogether.

A small video camera mounted on a pair of eyeglasses captures images of the wearer's surroundings. Those images are sent to a portable computer, worn on a belt, that converts each video frame into electrical signals. The timing and amplitude of each stimulation is critical to producing a good picture because the electrical signals are sent directly to electrodes in the brain.

Jens, a 38-year-old Ontario man who asked to be identified by first name only, is one of the first people to receive the Dobelle system.

Jens lost his sight almost 20 years ago in two unrelated accidents. He thought the Dobelle system, while still experimental, might help him and didn't let the $75,000 (U.S.) price tag deter him.

Jens' finally got the Dobelle gear last year and now looks every bit the bionic man, fitted with video camera, computer and wiring. The electrical jack on the back of his head is reminiscent of something sticking out the back of a computer.

Jens says all the expense, surgery and electrical wiring has been worth it. After years of living with blindness, he can see his children at the dinner table.

"I can't tell which children they are," Jens said of his black and white, low-resolution view of the world. "They don't even really look like children."

But he can see that someone is there — a significant step, Jens says, toward regaining the life he had before he lost his sight. Jens has only been using the implant regularly for a few months. The hope is that over time, the image quality will improve.

"This takes a lot of the awkwardness of daily life," he says.

Only 12 people in total have been implanted so far, with two more surgeries slated for this week, says Dr. Bill Dobelle of the Dobelle Institute.

"So far, they've all worked very well," he says.

The bionic ear is becoming almost commonplace. Douglas Lynch, director of corporate marketing for Advanced Bionics Corp., can hear today because of a cochlear implant made by the company in Valencia, Calif.

Lynch, 36, lost his hearing completely almost 10 years ago, when he contracted an autoimmune disease of the inner ear.

"When I lost my hearing, I had a Mustang with a V8 engine and I knew exactly what it sounded like," he says. But when he put the key in the ignition after getting the implant, he noticed the car didn't sound quite right.

There wasn't a problem with the engine. His brain just needed time to adapt. Gradually, Lynch says his brain re-mapped the sound he now heard coming from the car with the sound he remembered. Eventually, starting up the car sounded just as good as it did before he lost his hearing.

Lynch says his own adjustment is a testament to the plasticity of the human brain and its ability to adapt to bionics.

"It's the brain that's working overtime to try to fill in the gaps," he says.

Talking to him on the phone, one has to be reminded that he is deaf. His implant works so well, there is no need to repeat a question and his voice sounds fluid and natural.

Not every case works out this well.

People who are born deaf and hence have no auditory memory often have a hard time adjusting to the device and mapping all the new sounds to their visual counterparts.

The implant works by converting sounds into electrical impulses that are sent via electrodes to different parts of the cochlea, a spiral shaped part of the inner ear that Lynch equates to a rolled up piano keyboard.

Different areas of the cochlea are responsible for different frequencies of sound.

When cochlear implants were first developed in the 1970s, there was just one electrode that stimulated all of the inner ear. Current models feature multiple electrodes that go to different regions of the cochlea, allowing for a much greater range of sounds.

"They are very capable in terms of retaining a full spectrum of sound in the environment," Lynch said.

While the implant cannot be used in all cases of deafness, Lynch says it bridges the gap for hundreds of thousands of people.

The $45,000 device can be implanted as day-surgery but the procedure isn't risk-free. Health Canada and the U.S. Food and Drug Administration both issued notices last year indicating those with cochlear implants may be at greater risk for meningitis than the general population. There are only a couple dozen reported cases of people with cochlear implants contracting meningitis so far, but Health Canada is recommending people be vaccinated before getting the implant.

Meanwhile, research continues at Advanced Bionics as the company looks for new parts of the body to repair. The company is currently working on a system to aid people with urinary incontinence by stimulating the bladder with electrical signals to keep it functioning properly.

Advanced Bionics is also working with a sister company, called Second Sight LLC, on a bionic eye that would use cochlear implant technology to electrically stimulate the retina.

Unlike bionic eyes and ears, prosthetic limbs have been around since ancient times.

A Sanskrit writing from 3500 B.C. tells the story of Queen Vishpla, who replaced her leg — lost in battle — with an iron limb. While modern technology hasn't yet achieved the powerhouse limbs of Steve Austin, the parts are more than just a hunk of metal.

Today's prosthetic knees, for example, use hydraulics and microprocessors to co-ordinate leg movement at different speeds.

Adele Fifield, director of National Amputee Centre with the War Amps in Ottawa, uses such a knee. Costing upwards of $15,000, the knees are not cheap but, Fifield says, they are a significant improvement over previous models.

"Before microprocessor controlled units, you could walk at a standard gait comfortably, but anything slower or faster than that you have to wait for the limb to catch up," she says. "Now I can just suddenly start walking fast."

Prosthetic arms can incorporate the wearer's own muscular system. In a myoelectric arm, electrical signals from a remnant muscles can be picked up, processed and amplified as a means of controlling the motors in the limb. Those kinds of limbs can be expensive. Fifield estimates a myoelectric arm costs at least $15,000, with some units costing more than $50,000. A child amputee would require several limbs as the child grows.

The Bloorview MacMillan Children's Centre in Toronto has created an artificial limb that can be made to adapt to a child as the child grows.

At a young age, the child might be able to control only a single muscle for opening and closing an artificial hand. But as the child grows, and gains greater control, he or she might learn to flex two different muscles individually.

By downloading new software to the microprocessor in the prosthetic hand, the child can use one muscle to open the hand and another to close it. Because the change is simply a matter of swapping software, the device is significantly cheaper than previous ones involving all new hardware. And as the child gets bigger, the circuitry can be swapped to a bigger hand.

The problem that remains, however, is the weight and rigidity of the prosthesis itself. Motorized limbs can be heavy and stiff, unlike the soft expanding muscles of the human body.

That's where polymers come in. SRI International, formerly the Stanford Research Institute, has been working with certain polymers to use as artificial muscles.

It has long been known that certain polymers expand a little when an electric current is applied. Getting them to expand a lot was the challenge.

The stiff, copper electrodes that delivered the electricity to the polymer was physically holding it back from reaching full potential. SRI International devised a new, flexible kind of electrode made of carbon that moves with the polymer, enabling it to expand almost five times its original size.

Philip von Guggenberg, director of business development for SRI International, says the company is in "a very active discussion" with a company in the United States to develop a prosthetic device using the polymer as an artificial muscle.

There are also researchers who want to take the whole thing closer to the expectations set by science fiction — to develop systems that would give people truly super-human capabilities.

A company called Yobotics, in Malden, Mass., has developed a device that allows people to do knee bends all day with 120-pound backpack.

"Normally, you can only do 30 to 50 of them if you're good shape," says company co-founder Jerry Pratt. "With the device you can do them without getting tired."

He says the mechanical apparatus, which is worn externally on the leg, also assists in mountain and stair climbing.

The U.S. military would like to take bionic limbs one step further. Its interest is war. It doesn't simply want replacement parts for fallen forces. It wants faster, stronger soldiers, like the $6 million man.

In 2000, the U.S. Defense Advanced Research Projects Agency, or DARPA, set aside $50 million (U.S.) to develop "exoskeletons for human performance augmentation."

Working with a handful of specialized companies, DARPA hopes to make wearable gear that will enhance the average soldier's capabilities. It wants soldiers to be able to run faster and lift more gear with ease.

"Exoskeletons will also increase the lethality and survivability of ground troops for short range and special operations," says the project's initial call for research proposals. "The enhanced mobility and load carrying capability provided by the exoskeleton will allow soldiers to carry more ballistic protection and heavy weaponry."

An early, non-functional version of the suit, developed in partnership with Sarcos Research Corp. of Utah, was trotted out for publicity shots last March.

It featured large pieces of black Plexiglas, worn over the soldier's body, with hinges at various joints. A legs-only version of the suit is expected to be ready for testing this year, with testing for a full body suit slated for 2005.

DARPA's budget alone makes clear that a real-life version of Steve Austin would cost a lot more than $6 million, even accounting for inflation. We've already sunk far more than that into the research and development of prosthetic eyes, ears, arms and legs.

And the effort is changing lives. Lynch can hear his car start in the morning. Jens can see his children. Fifield can run or walk as she pleases.

It's not exactly fodder for a great spy movie but it's a start.

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