Wireless Multi-Modal Brain Monitoring

DESCRIPTION (provided by applicant): Over the last two decades, there has been a growing need to record electrical signals directly from the brain in humans and animals, especially in candidate patients requiring resective epilepsy surgery. At the same time, there is an increasing demand for real-time monitoring of a larger number (gt200 channels) and different types of electrodes and modalities to provide adequate spatial and temporal resolution for pathophysiology; a challenge that becomes self-limiting and intractable with current state of practice. ITN Energy Systems, in collaboration with Yale University Epilepsy Program and Ad-Tech Medical Instruments Corporation will bring their unique expertise in biocompatible materials and sensors, nanoscale electronics, neurosurgery, neuroscience, and manufacturing, marketing and commercialization of brain implantable electrodes to develop an enabling wireless, multi-channel intracranial electroencephalogram (icEEG) implantable system/device. In the Phase I effort, we were able to successfully design and fabricate an implantable icEEG measurement and recording device. Successful operation of the device was validated as a free-standing system and then subsequently implanted in three rodents. The implanted monitoring system measured and recorded icEEG signals over the course of several days, including successful demonstration of remote powering using a radio frequency (RF) inductive link and the wireless transmission of icEEG data with a high bandwidth infrared communications link. The goal of the Phase II project will be to expand the Phase I 5-channel system for rodents into a 64-channel system with continuous icEEG recording (0.1 to 500 Hz at a 1 KS/sec sampling rate) for direct application in humans. In particular, we will 1) Optimize the current inductive RF link (13.56 MHz) and power management circuit design to reduce the footprint of the implant antenna, insure MRI safe operation, and incorporate the option of on-board power storage feature (battery and/or capacitor) for continuous uninterruptible operation, 2) Improve and expand the existing infrared link by developing and implementing software to support an IrDA protocol, 3) Reduce overall footprint by 30% using die level components on a lightweight substrate, 4) Conduct extensive biocompatibility and toxicity testing for short and long term applications, and 5) Conduct thorough rodent tests, using expanded 4 by 8 and/or 8 by 8 electrode grid arrays to optimize performance and robustness of the device. Successful completion of Phase II will validate critical building blocks of a multimodal implantable icEEG system that is inherently expandable to meet the growing needs for hundreds of measurement channels. These advances move the device towards use in patients and subsequent product development and commercialization. PUBLIC HEALTH RELEVANCE: This project proposes the design and testing of a wireless, 64-channel implantable system for the continuous recording of icEEG signals from the brain. Such a wireless system will not only eliminate tethering of patients to EEG equipment but expand the number of channels surrounding the seizure onset region in medically intractable epilepsy patients requiring surgery, monitoring of brain trauma, and the understanding of other neurological disorders. The proposed implantable technology will facilitate the direct access of electrical activity within the brain via wireless transmission of a high resolution, digital data stream that links directly into a portable laptop or waste-worn data storage system.