OU prof works on implantable hearing aid

by William Hilderbrandt

Editor: Work continues on fully implantable hearing aids. The main roadblocks continue to be battery life and surgery costs. A professor at Oklahoma University is moving ahead on an implantable aid with some interesting innovations. Here's the story from the OU Daily (http://www.oudaily.com). It is reprinted with their kind permission.

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Rong Gan is developing world's first totally implantable device

April 10, 2006

An OU professor is currently developing the world's first total implantable hearing system.

The device would be surgically implanted behind the ear and consist of three parts: a microphone and sound processor, a coil and a magnet implant.

Rong Gan is an associate professor of mechanical engineering and the Charles E. Foster Chairwoman in biomedical engineering.

Her technology is revolutionary in three ways.

It is the first completely implantable system, the first to use electromagnetic waves to recreate a natural hearing process and the first to treat sensorineural hearing loss, the most common form of loss.

She said current devices do not adequately approach the problem. To treat hearing loss successfully and relieve patients of visible aids, something innovative had to be done.

"Our purpose is to get into the inner ear," Gan said. "It's more natural, it's more clear. Conventional hearing aids are just acoustic amplifiers stuffed into the ear canal."

Previous methods used a "microphone-speaker" form of amplification.
In simple terms, they only turned up the volume.

This created two problems: All sounds, even in the background, were heard at the same volume and there was an abundance of feedback noise that could lead to burdensome headaches.

Gan's processor relays sounds at a volume proportionally, and it has zero feedback noise by using electromagnetic waves.

The processor sends an electrical signal down a coil that converts it into electromagnetic waves.

These waves then "drive" the implant, which will convert them into a mechanical vibration that stimulates the adjacent cochlea.

Basically it works, but in a significant way.

It is the first method to directly combat sensorineural hearing loss, which affects 80 percent of people with hearing loss.

The innovation is also small and safe.

The implant itself measures less than 1.5 by 2.5 millimeters, and all the components are made of biocompatible titanium.

Despite having two U.S. patent applications pending, the device is still just a prototype until Gan and her team choose a company to manufacture it.

"Right now, it's homemade," Gan said jokingly. "Progress is gradual."

Gan's device is set to revolutionize the industry after five years of research.
The same way her device is seeking FDA approval in stages, Gan said developing it operated in stages as well.

"Basic research is to understand the human body, applied research is to use this knowledge to help people," she said. "Bioengineering is combining engineering with medicine."

Sifting through files and folders on her desk, she spoke about her current concerns with the device.