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December 3, 2002

HEATHER NEWMAN: Center works on ways to restore senses

From: Detroit Free Press, MI - 03 Dec 2002

The Center for Wireless Integrated Microsystems is working on ways to give back hearing, muscle control and maybe sight

December 3, 2002


Michigan researchers are working on tiny gadgets with enormous goals: offering high-quality hearing to deaf people, motor control to people who have seizures or tremors and someday, perhaps, sight to blind people.

All three functions rely on one simple-to-describe, hard-to-build technology: The ability to collect information and turn it into precise electrical signals delivered directly to the human nervous system.

The Center for Wireless Integrated Microsystems, a joint project of the University of Michigan, Michigan State and Michigan Tech, is leading the research in Ann Arbor. So far, they've produced an improved cochlear implant -- a controversialdevice that translates sound into electrical stimulation of the ear's nerves and gives a limited number of deaf people some hearing. The implant is many times smaller and, simultaneously, more powerful than current models.

Basically, the device is a normal-sized flat battery attached to a toothpick-sized strip of what looks like mylar. It's called a thin-film electrode array. The strip is designed to be inserted into the ear and wound around the spiral-shaped path to the inner ear.

The tip of the device is loaded with points that can stimulate sensitive areas of the inner ear electrically. The new device has many more stimulus points than can be built in the cochlear implants available today. That's important, because the more precise the device can be about where and how it stimulates nerve fibers, the more it can simulate a full range of sounds.

A small processor is built into a clip-like device that rests behind the ear. It captures sounds and translates them into electric pulses to send down the strip.

The new implant is still in the animal testing phase -- the first device was implanted in a guinea pig last week. It's the farthest along of the devices the Wireless Integrated Microsystems scientists are working on.
Going with the flow

Designing any implant like this is challenging, said Joseph Giachino, director of external programs for the center. These are micro-machines. They are incredibly tiny and incredibly complex, and the human body is one of the hardest environments to build for.

"You need to have something that's compatible with the body and won't be attacked by the body," he says. "You have to design the thing such that the parts that have to be protected are, and those that have to be exposed are, andthe two are connected. Outside of that, it's really simple."

Bryan Pfingst, a professor in U-M's department of otolaryngology, says last week's surgery was to test the procedure Michigan Tech researchers developed to place the implants in the ear precisely.

Eventually, many more guinea pigs will be implanted. They've been trained to press a button when they hear particular sounds, and to hold down the button and release it when sounds change.

Experts are looking forward to thin-film implants being approved for people. Dr. John Niparko, director of the Division of Otology, Neurotology & Skull Base Surgery at the Johns Hopkins Hospital in Baltimore, has performed more than 800 cochlear implants using the existing technology. He did the highly publicized implant surgery on former Miss America Heather Whitestone McCallum in the summer.

"Implants have gotten smaller, faster and smarter; more like the human ear," he says. "The cochlear implant can almost guarantee some hearing. The technology that's being developed at the University of Michigan addresses the needs that many deaf people have. I think they're on the right track."
Some harm with the benefit

Current cochlear implants have a number of drawbacks. They require major surgery, for one, and can eliminate any remaining natural hearing. Because of the trouble involved, most people who opt for the implants get them on just one side, making it difficult to clearly hear sounds coming from the opposite ear.

Experiences with the implants vary in terms of how much people can hear and how much sense the sounds makes. Some people who lost their hearing late in life say it sounds like a bad AM radio station. Others find they're able to hear all single sources of sound clearly, such as the voice of a person they're talking with, but they don't enjoy more complex sounds, like music, because of poor balance.

Because of their large size, current cochlear implants often stimulate several nerve fibers at once, so people might hear "ah" and "ooh" as roughly the same sound. And because every implant is essentially handmade, they're extremely expensive -- up to $30,000 including the cost of the surgery.

The new implants aim to correct some of the drawbacks. The additional transistors on the end of the implant are intended to make the device more precise and to offer greater sound quality. Lower power draws mean batteries won't have to be replaced as often. And because they could be mass-produced, they're likely to be much less expensive, and that might make double-implant operations common.
Patient, spokeswoman

Donna Sorkin of McLean, Va., was considered a poor candidate for an implant 10 years ago. She had started losing her hearing more than a decade earlier, and was 39 when the operation was done.

Most physicians prefer implant patients to be quite young, so they can learn the listening techniques required to sort out the sounds from the implant. But she's never regretted the decision, and now works for Cochlear America, a company that makes current-generation implants.

"I got off the plane and had a message on my cell phone to call" Niparko, she says. "I had a five-minute conversation on a cell phone. Now I'm talking in a car with two children in the back seat. I'm deaf. Without this implant, I can't hear anything. I had never used a cell phone before. I hadn't used any kind of phone for four years. The freedom that it's given me is I can travel, and do things."

The voices of the people she knows sound much like she remembers them, Sorkin said. Situations where there are a lot of conflicting sounds are still difficult to handle.

"It's better than I thought it was going to be. The sounds of birds in the summer is really beautiful. I can even identify a bird by its song. I never dreamed I would be able to do that again," she says. After the surgery, her young son razzed her about being surprised by her car alarm, she says.

McCallum has had a similarly joyful experience hearing new sounds, Sorkin says. She was speaking from McCallum's car during a recent visit to Atlanta. But because she has been profoundly deaf since she was 1 and got the implant at 29, McCallumhas a long way to go before she's able to do things like use a cell phone in a car crowded with youngsters -- if she ever does.

Sorkin and McCallum don't represent the entire deaf and hard of hearing community in their decisions to have the surgery. There is a segment that feels implant surgery isn't necessary and can harm the social adjustment of deaf people by making them neither fish nor fowl.

"The person suddenly is looked upon as neither hearing nor deaf," says Sparks-Chellee Phillips, president of Onward & Upward Enterprises in Valparaiso, Ind. "Hearing people see the bulge and the wires and know the person is implanted with something that differentiates him from others. Deaf people, on the whole reject cochlear implants and those who are implanted. Thus, these are people without a culture."

She also worries about the physical side effects of the implant surgery. It can cause seizures if there are infections and prevents patients from getting MRIs. Having it rules out contact sports, too.

Still, those arguments are unlikely to alter the progress of the scientists working on new and better implants. What may be more exciting is the possibility that the same technology could be used down the road to assist people who have other disabilities.

Giachino said the center has designed a prototype that looks like a microchip with multiple thin-film fingers forming rows off the bottom. It could be implanted in a precise point along the spine, and monitor the nervous system activity that stimulates tremors among people with Parkinson's or other diseases, or seizures among people who have epilepsy.

The device could add its own stimulation to the nervous system, and possibly inject medicines, to counteract the effects. Giachino said he's seen demonstrations of external devices that returned full motor control to a person with severe Parkinson's tremors.

The holy grail, of course, is a gadget that could offer blind people the opportunity to see. Right now, the limitation is the sheer amount of information involved in the three-dimensional picture our eyes draw electrically.

No technology currently available could absorb all that information, translate it into the incredibly complex electrical impulses it would require, and transfer those to the appropriate tiny points on the brain -- let alone process it fast enough to practically serve as replacement sight.

But that doesn't mean scientists aren't continuing to try.

"Will we get there? Sure," Giachino says. "In my lifetime? Probably not."

Contact HEATHER NEWMAN at 313-223-3336, or

© copyright 2002 Detroit Free Press