Minimally Invasive Subdermal Wireless EEG Sensor Arrays for Home Monitoring of Epilepsy

Currently, the principal diagnostic method for the large patient population, like those with epilepsy, is based on short term stays in a hospital. Therefore, it is increasingly recognized that for many patients, it can be of paramount importance to be able to record neural activity continuously over weeks and months since a clinically informative assessment could vastly improve clinical diagnostics and patient care. We propose a scalable approach for a multielectrode, minimally invasive wireless EEG device for long term neurological event monitoring in home and mobile use. At the core of the proposed technology is a monolithic wireless sensor, a millimeter-wide, less than quarter millimeter thick multielectrode polymer strip, several of which can be inserted in a doctor’s office into subdermal space using a syringe type of carrier for recording brain signals over large areas. A tiny radio chip is integrated in the strip which is externally powered and transmits EEG signals through the scalp to an external receiver. In a first step, we demonstrate the capability of the 500 µm × 800 µm four-channel custom ASIC to record gamma band EEG signals in saline when integrated onto the multielectrode strip.