Wednesday, May 2, 2012

Developing Early Warning System

Epilepsy affects 50 million people worldwide, but in a third of these cases, medications are unable to keep seizures from occurring. One solution is to shoot a short pulse of electricity to the brain to stamp out the seizure just as it begins to erupt. But brain implants designed to do this have run into a stubborn problem in that too many false alarms are triggering unneeded treatment.

To solve this problem, Sridevi Sarma a Johns Hopkins Assistant Professor of Biomedical Engineering has devised new seizure detection software that in early testing has shown a significant cut in the number of unneeded pulses of current that an epilepsy patient would receive.

Sarma’s new software has been tested on real-time brain activity recordings collected from four patients with drug-resistant epilepsy who experienced seizures while being monitored. In a study published in the journal “Epilepsy & Behavior”, Sarma’s team reported that the system yielded superior results, including flawless detection of actual seizures and up to 80 percent fewer alarms when a seizure was not occurring. Although the testing was not conducted on patients in a clinical setting, the results are promising.

Further fine tuning of the seizure detection software is underway using brain recordings received from more than 100 epilepsy patients at Johns Hopkins Hospital where several epilepsy physicians have joined in the research. Sarma hopes that within two to four years, she hopes to see her system incorporated into a brain implant that can be tested on people with drug-resistant epilepsy.

The research focuses on a system with electrodes implanted in the brain connected by wires to a neurostimulator or battery pack, and a sensing device also located in the brain implant that detects when a seizure is starting and activates the current to stop it.

Ideally, Sarma would like to see the software embedded in a microchip that would continually check electrical activity in the brain and launch electrical stimulation whenever, a seizure is just beginning to form. The device would operate as a closed loop system.

Her team’s new system for seizure detection with reduced false alarms is protected by a patent obtained through the Johns Hopkins Technology Transfer office.

For more information, email Stridevi Sarma at