"We plan to spend this $6.7 million to further develop technology that we hope will someday help blind individuals see, allow paraplegics to stand and eventually walk, and let people with vocal cord problems speak," says Richard Normann, a professor of bioengineering and ophthalmology who is helping spearhead the project.
The money is in the form of four grants from the National Institutes of Health to scientists at the university's College of Engineering and University of Utah Health Sciences Center. The projects receiving the funding are intended to expand the Utah Electrode Array technology that Normann first developed in 1989.
The Utah Electrode Array is a silicon chip measuring a quarter-inch on each side and containing 100 tiny electrodes in a 10-by-10 grid. The array is implanted under the dura, which is the membrane covering the brain.
Normann pursued commercial development of the Utah Electrode Array by forming a spin-off company name Bionic Technologies, LLC, which he and co-owner Brian Hatt sold to Cyberkinetics Neurotechnology Systems, Inc. in 2002. Cyberkinetics incorporated the array and other technologies into its BrainGate System, and implanted a Utah Electrode Array into a paralyzed human patient for the first time in June 2004. The electrodes, which poke into the part of the brain controlling movement, allowed the patient to control a computer screen cursor by thinking about moving the cursor.
Now, "we are trying to make the system even better" by developing a "smart" wireless electrode array so it won't be necessary for people using the device to have 100 wires emerging from their skull, something that raises the possibility of infection and also of getting the wires snagged while the person is using a wheelchair, Normann says.
"To go from a bundle of wires sticking out of somebody's head to a totally implantable system that is invisible will be a major advance in this technology," he adds.
Normann has spent more than a decade developing the Utah Electrode Array so it eventually can be implanted in the brains of blind people. They would wear a tiny eyeglass-mounted camera to collect visual information, and then relay it to electrodes in the brain's visual cortex. The wireless array would make such an artificial vision system easier for blind people to wear and use.
Here are details of the four grants, which total as much as $6.658 million:
They will develop a wireless version of Utah Electrode Array, which will look much like the original but will be slightly larger and "will have electronic circuitry integrated into it to amplify the signals from each of the 100 electrodes, do signal processing on those signals [to filter out noise and other unimportant information] and send those signals wirelessly to a receiver located outside of the body," Normann says.
The researchers will use a version of the electrode array that has electrodes of varying lengths, from 0.5 to 1.5 millimeters, so that when it is implanted on nerves that control the legs or arms, it will come into contact with multiple nerve fibers within a nerve and not just those at a single depth within the nerve.
"This opens up a whole bunch of new applications, one of which is to implant these electrodes in the peripheral nerves of the legs of a paraplegic," says Normann. "We believe that if we implant three Utah Electrodes Arrays into three different nerves in each leg - a total of six electrode arrays - and stimulate them appropriately, we should be able to help the paraplegic to get out of the wheelchair, stand up and eventually walk using his or her muscles," although that won't be tried until after pre-clinical feasibility studies.
Another use would be to implant the array in nerves that control the bladder, with the array run by a switch. This could allow a paraplegic to regain control of urination.
So far, nonfunctioning arrays have been implanted in nine temporal lobe epilepsy patients before they underwent unrelated brain surgery for their disorder. The tests found no problems. The arrays have been implanted in animals for up to three years. Nevertheless, the body's immune system tends to "wall off" any foreign material implanted in the brain, so Tresco and Normann will develop new coatings for the array "so the brain is even more unaware of the fact it has been implanted," Normann says.
Smith says the project will determine the feasibility of using a Utah Electrode Array to restore the ability to speak in certain people by stimulating nerves that control the vocal folds (also known as vocal cords), which are the voice-producing folds of tissue in the voice box or larynx.
The vocal folds open when we breathe and close when we speak. Some people lose their voice when a vocal fold is paralyzed by stroke; trauma; damage during surgery of the neck, thyroid or chest; or a tumor that impinges on the nerve to the vocal fold.
"This device is going to be used in an attempt to reanimate the vocal folds to restore the normal movement, both the opening and closing movement of the vocal folds," Smith says.
The existing Utah Electrode Array will be used in initial tests, but Smith says he hopes a wireless version ultimately will be available to help restore speech.
Scientists at the New York State Department of Health recently gained publicity for a noninvasive method of allowing paralyzed people to control computers or other devices by reading brain signals using 64 electrodes in a cap placed on the scalp. Its major advantage is that nothing needs to be surgically implanted.
But Normann says the method has a big disadvantage, namely, that signals from nerve cells in the brain are weak and "smeared" together by the fact that the skull and scalp jumble the signals, meaning a paralyzed person using the device could control a computer or other device only very slowly and with considerable training.
Implanted electrodes can more precisely "listen" to individual nerve cells and record their activity, allowing paralyzed people to control computers or their own limbs much more quickly, Normann says.
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