Medary.com

At Science Blog:
Brain implants predict and prevent epileptic seizures:

One research project focuses on a tiny transmitter three times the width of a human hair to be implanted below the scalp to detect the signs of an epileptic seizure before it occurs. The system will record neural signals relayed by electrodes in various points in the brain, said Pedro Irazoqui (pronounced Ear-a-THOkee), an assistant professor of biomedical engineering.

"When epileptics have a seizure, a particular part of the brain starts firing in a way that is abnormal," Irazoqui said. "Being able to record signals from several parts of the brain at the same time enables you to predict when a seizure is about to start, and then you can take steps to prevent it."

Data from the implanted transmitter will be picked up by an external receiver, also being developed by the Purdue researchers.

The most critical aspect of the research is creating a device that transmits a large amount of data at low power. The transmitter consumes 8.8 milliwatts, or about one-third as much power as other implantable transmitters while transmitting 10 times more data. Another key advantage is that the transmitter has the capacity to collect data specifically related to epileptic seizures from 1,000 channels, or locations in the brain, Irazoqui said.

"The fact that this circuit can deliver such a vast amount of data and, at the same time, be less power hungry than anything else that's out there is what makes this important," he said.

Another implant project seeks to monitor eye pressure in order to prevent onset of glaucoma:

"Glaucoma is one of the big two irreversible, but preventable, causes of blindness," Irazoqui said.

The disease causes blindness from a buildup of fluid pressure in the interior chamber of the eye, killing fibers in the optic nerve. Glaucoma patients go to the doctor periodically to have their eye pressure checked. If it is high, the doctor prescribes medication or performs surgery.

"The problem is that your interocular pressure spikes over hours, sometimes minutes," Irazoqui said. "So you can be fine today and fine in six months and spend three months in the middle where it's very high, killing your optic nerve. What you really need to do is check it often, every couple of minutes, but you can't go to the doctor every couple of minutes for the rest or your life. So what you need is a device that measures your eye pressure continuously."