[Nfbf-l] Human-machine mergers promising, but reality yet to live up to hype

[Carolyn Lapp]

    By Grant Buckler, special to CBC News, Tuesday, May 25, 2010.

Jens Naumann had been blind for 19 years. But in 2002, in a Portuguese 
hospital, the Canadian, then 39, began seeing flashes of light, then shapes 
of large objects.

That's because he was the first recipient of a brain implant called the 
Dobelle Eye.

Biomedical researcher William Dobelle worked for years to wire a tiny camera 
to a brain implant so people with irreparably damaged eyes might see again. 
It was an example of work being done in the field of neuroprosthetics, which 
explores making electronic devices communicate directly with the brain. One 
of the most common neuroprosthetic devices, the cochlear implant, has 
already helped nearly 200,000 people with hearing loss.

But technology to restore vision is still in the early development stages.
Naumann says the Dobelle Eye implant gave him only rudimentary vision: "It 
is like seeing in a way, because you did feel a visual awareness."
Still, he could navigate around obstacles, locate objects and, with 
practice, read block letters 10 centimetres high. He even drove a car - 
slowly - in a parking lot. Sadly, it didn't last.

"The device was pretty functional for as long as you could baby it and 
doctor it," Naumann recalls. But after Dobelle's death in 2004, Naumann 
could not maintain it. The implant is still in his brain, but infections 
forced removal of the connectors placed in his skull to connect the external 
camera.

Sixteen patients had the implant, he says, but none had better luck than he 
did.
The device was never approved in the U.S. or Canada - all operations were 
done in Portugal. Dobelle demonstrated the promise in feeding visual 
information directly into the brain - but also that was not ready for 
widespread use.

Neuroprosthetic progress.

It still isn't - but promising work continues in a number of areas.

While Dobelle placed his implant on the surface of the brain, for example, 
Mohamad Sawan, Canada research chair in smart medical devices and director 
of the Polystim Neurotechnologies Laboratory at Montreal's Ecole 
Polytechnique, is working on one with a needle-like probe that enters the 
cortex to reach the precise area where the optic nerve goes. Like Sawan, 
other researchers are going right into the brain so they can use weaker but 
more efficient electrical signals.

Sawan uses radio waves to connect his external camera with the brain 
implant, so there is no need for the external connectors that caused 
problems for Naumann.
The technology is still in the trial stage, Sawan says, but the use of these 
types of implants in humans might be possible in as little as four to five 
years.

His implant will allow patients to see low-resolution images, he says, but 
it will be possible to zoom in on objects, so patients should even be able 
to read:
"The patient can be completely independent."

While brain implants best suit people whose eyes are damaged past repair, 
other researchers are creating implants that go in the eye itself, 
stimulating the retina to overcome problems including macular degeneration 
and retinitis  pigmentosa.

Optobionics of Glen Ellyn, Ill., has developed a tiny chip that stimulates 
dormant retinal cells when implanted in the eye. Alan Chow, Optobionics' 
founder, says his team initially expected electrical impulses from the chip 
would simply allow patients to see some light, but they actually stimulated 
dormant cells to start functioning again, restoring near-normal vision.

Trials in about 40 patients showed that while the implant won't restore dead 
retinal cells, it works in the approximately 60 per cent of cases where 
cells are simply dormant. But faced with costs of hundreds of millions of 
dollars for more extensive testing before the device could get regulatory 
approval in the U.S., Optobionics' backers have pulled out. Chow is trying 
to revive the company, and says simpler approval procedures in Canada might 
allow his technology to be used here first.

The Boston Retinal Implant Project has tested a similar implant that 
bypasses dead photoreceptors in the eyes of patients who suffer from macular 
degeneration and retinitis pigmentosa. The researchers plan human trials of 
their latest prototype soon, and Shawn Kelly, a researcher with the project, 
says the implants would probably cost $40,000 to $60,000 (including 
surgery) -  similar to the cost of a cochlear implant.

Restoring movement.

Vision is just one area of neuroprosthetic development. Researchers are 
exploring ways to use neuroprosthetics to restore broken communications 
between the brain and other parts of the body, which could restore natural 
movement to people who are paralyzed or allow their brains to control 
prosthetic replacements for missing limbs.

A key to neuroprosthetics is the fact that the human nervous system uses 
weak electrical impulses to transmit information. The Utah Electrode Array 
is a tiny device - less than a sixth the size of a penny - that when 
implanted in the body can "talk" to nerves, telling parts of the body what 
to do.

Imagine a person paralyzed by spinal cord damage. The muscles function, but 
the brain can't communicate tell them to move. An electrode array can 
stimulate those muscles, says Greg Clark, associate professor of 
bioengineering at the University of Utah, giving the patient some motor 
control.

There are already simple systems that do this, Clark says, but they lack the 
fine control to produce smooth and efficient movement, so patients move 
awkwardly and tire quickly. By transmitting more data, the Utah Array should 
allow more precise control.

Clark says the ultimate system would use one pair of arrays to relay signals 
from the brain to nerves in, say, a leg, and two more arrays to return 
sensory feedback from the leg (so patients would feel their foot touching 
the floor, for instance).

One scientist has already tested an electrode array collecting sensory 
feedback in his own arm, and all the necessary components have been tested 
in animals. However, a complete two-way sensory and muscle control system 
has not yet been built and tested in people, he says.

Other projects focus on using the brain to directly control devices outside 
the body. The BrainGate Research Team, with researchers at Brown University, 
Massachusetts General Hospital and Providence VA Medical Center, has tested 
a brain implant that can use signals from the brain to control a computer 
cursor.

Reasoning that fine muscle control is a difficult problem, University of 
Washington researchers are taking a different tack. The Neural Systems Group 
is experimenting with a small humanoid robot controlled by sensors worn 
outside the head. Because the robot has intelligence of its own, "when you 
tell it to  pick up an object you don't have to tell it how to move its 
hand," says Rajesh  Rao, associate professor of computer science and 
engineering. So imprecise  signals from many neurons - detectable without an 
invasive implant - are enough.

Rao says the control system could use a menu where options would flash on a 
screen one by one, and the sensor would detect the user's recognition of the 
one wanted. The robot would also learn, so having once been taught step by 
step how to go to the refrigerator, the next time it would know the way.

Because this system would be worn, not implanted, approvals for its use 
should be easier, and Rao says possible entertainment uses of the technology 
could help bring the price down. Like most of today's neuroprosthetic 
research, it will take time to reach the point where the technology is ready 
for real-world  use.

Still, progress is being made in many areas that help meld humans and 
machines.
Jens Naumann's brief glimpse of the world a few years ago was a landmark 
event, and medical technology is going to make that world a lot more 
accessible to people with a range of physical challenges in the coming 
years.

Source URL:
http://www.cbc.ca/technology/story/2010/05/10/f-buckler-neuroprosthetics-med
ical-technology.html

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