Intracranial EEG monitoring, the measurement of electrical activity directly from the cortex and sub-cortical structures, is routinely performed in humans who are candidates for resective epilepsy surgery. Similar measures are routinely performed in animals for studies of neural function and dysfunction. In humans who are being considered for epilepsy surgery up to 200 sensors are placed on the cortex and in selected subcortical structures using strip, grid and depth (Spencer Depth Electrodes) electrodes. The electrodes are maintained in place for a duration which ranges from days to weeks and brain electrical activity is continuously monitored until the patient's habitual seizures have been observed. The intracranial EEG recordings help plan the surgical procedure by locating the seizure onset area, the areas where seizures spread, as well as the location of critical cognitive functions. There are several critical limitations of the current technology. The need to have patients tethered to the EEG system increases the infection risk and surgical time and decreases patient mobility and tolerance of the recordings. The goal of this Phase I project will be focused on developing wireless transmission of four channel EEG signals with testing in rodents. An implantable wireless transmission system and an external transmit/receive unit will be developed as part of this effort; the system will use RFID technology to power the implant by means of a 13.56 MHz carrier and transmit/receive data by means of a direct infrared link to a personal computer (minimal heat dissipation without the need for an implantable battery). The device will initially be tested in rats to ensure that the system is feasible for human use and also because there is a market for these wireless transmission systems for a number of animal research directions. Besides epilepsy, these include sleep, trauma and behavioral monitoring. These rat studies will be critical in determining the refinements needed to be addressed as part of a Phase II trial aimed at using this technology in patients. ? ? ?
