Purdue University researchers have developed new miniature devices designed to be implanted in the brain to predict and prevent epileptic seizures and a nanotech sensor for implantation in the eye to treat glaucoma.
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 research represents half of a larger collaboration at Purdue focusing on creating a neuroprosthesis that dispenses a neurotransmitter called GABA and calms the brain once the onset of a seizure is detected. This work is a collaboration between Irazoqui and Jenna Rickus, an assistant professor of biomedical engineering.
Another biomedical engineering project from Purdue involves the development of a sensor to be implanted in the eye to monitor glaucoma by measuring pressure in the eye's interior.
"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."
The pressure sensor, which is placed between two layers of tissue in the eye, measures the interocular pressure and transmits the information to an external receiver so pressure can be continuously monitored, Irazoqui said.
The Purdue researchers are planning to conduct animal trials by December and human trials within 18 months. The latter device is fully implantable and includes a battery.
Illustration: Pedro Irazoqui, assistant professor of biomedical engineering at Purdue. –Purdue News Service photo/David Umberger.
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