22.7 A Programmable Wireless EEG Monitoring SoC with Open/Closed-Loop Optogenetic and Electrical Stimulation for Epilepsy Control

The number of studies on closed-loop detection and electrical stimulation systems [1]–[2] for efficient control of neurological disorders is increasing, because recent clinical studies have shown their efficiency and usefulness in symptom suppression. Electrical stimulation can produce enough stimulation to affect a large range of nerves. However, all nerves near the stimulus are excited and hurt, and over time, currents start to exceed acceptable limits. Therefore, optogenetic stimulation [3]–[4] has become compelling in recent years due to several advantages: (1) no artificial noise on the EEG; (2) ability to stimulate specific nerves; and (3) no injurious effects on nerves. In this study, a wireless programmable stimulating system-on-chip (WPSSoC) is reported that provides wireless open/closed-loop optogenetic and electrical stimulation to improve treatment for epilepsy suppression. The system is demonstrated on programmable stimulation parameters wirelessly controlled by a software Graphical User Interface (GUI) on a computer. Moreover, an animal experiment conducted on optogenetic tissue was successful, thereby demonstrating that the nerve injury on optogenetic stimulation is lower than that of electrical stimulation.