Miniature devices treat epilepsy, glaucoma.

• Position: Implants

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 have been developed by researchers at Purdue University, West Lafayette, Ind.

A tiny transmitter three times the width of a human hair can be implanted below the scalp to detect the signs of an epileptic seizure before it occurs. The system records neural signals relayed by electrodes in various points in the brain, indicates Pedro Irazoqui, 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 explains. "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 is picked up by an external receiver.

The most critical aspect of the research is creating a device that transmits a large amount of information 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 information. 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. While the transmitter and its battery are implanted below the scalp, the electrodes that pick up data are inserted directly in the brain through holes in the skull and then...