Better Living Through Implants
Imagine if you could learn to fly a helicopter by downloading software directly to your brain. Imagine if your eyes could see an object, overlaid with data, miles away in the dark. These science-fiction scenes from The Matrix and Terminator movies may be less fictional in the future, thanks to the fascinating science behind medical implants.
Interdisciplinary teams of surgeons, researchers, engineers, and computer scientists are creating complex electronics designed to work within the human body to simulate human functions. Today's bionic technology helps people suffering from disease or disability, and may pave the way to a future where the blind can see and the deaf can hear. Researchers have achieved breakthroughs in medical science, but the level of improvement these advances offer doesn't approach the level of typical human sight, sound, thought, or movement.
But implants are getting better, faster, and smaller; and experts say that they could be used to augment healthy human performance within five to ten years. A look at the current research in medical implants shows not only unprecedented potential for curing disease but also a new paradigm for understanding human potential.
Since the late 1980s, the Boston Retinal Implant Project has been working to develop an eye implant for treating retinitis pigmentosa and age-related macular degeneration, two leading causes of blindness. The airtight titanium implant contains a 200-channel chip that sits in the eye socket and a wire coil that encircles the iris of the eye; a wireless computer-based controller outside the body handles data transfers. MIT visiting scientist and project member Dr. Shawn Kelly has been working on the project for 14 years. He expects to start human clinical trials in three years.
Patients fitted with the implant will wear glasses with a camera and carry a small pocket computer with a battery. The computer will read and analyze images and then send data to the implant, which will use electrodes to deliver electrical impulses to retinal nerve cells. They will see hundreds of pixels of data, rather than the millions of pixels of healthy sight, and they will need therapy to teach their brains to interpret the patterns of dots and color information.
"It will be a pixel scoreboard kind of image," says Kelly.
But could implants eventually move beyond correcting vision to making it superhuman? Kelly speculates that the field of brain/machine interfaces, including the interface related to eyesight, will move toward performance enhancement, but any such application is a long way off.
"It's just not there yet to risk someone with totally healthy vision," says Kelly.
But even if the implant weren't ready to dole out bionic vision, what if the input device were? What if you replaced the camera used to feed images to the implant with a night-vision camera that could give the user sight in total darkness?
That's the hypothetical scenario posed by Dr. Brian Mech, vice president of business development at Second Sight Medical Products, whose Argus II eye implant system is currently in clinical trials.
The Argus II consists of electronics implanted in the eye, a camera mounted in sunglasses, and a video processor and battery pack worn on a belt. The implant has 60 electrodes, which loosely translates to a total of 60 pixels in an entire image. Keep in mind that a standard Web graphic contains 72 pixels per square inch; still, in the night-vision scenario, 60 pixels might be better than what you'd see on your own when the lights go out.
The previous Argus model had 16 electrodes. The next generation will have 240 electrodes, and a 1000-electrode device is on the drawing board.
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