Jazlin

Abstract: A novel treatment strategy for network-based psychiatric disorders is phase-locked neurostimulation. Recent electrophysiological data has shown that cross-regional synchronization of oscillations affects communication between neurons within networks.However, currently available neurostimulation systems do not have the capacity to perform closed-loop, phase-locked deep brain stimulation (DBS) between regions of the brain. The purpose of our project is to create and validate the performance of a new application specific integrated circuit (ASIC) for real-time phase estimation in an implant-feasible power budget.We conducted an in vitro saline experiment using clinical DBS leads to characterize intrinsic and extrinsic noise of our system. We found that the intrinsic electronic noise contributed to <1% of the total input-referred noise (1-500 Hz), and that DC offsets on clinical DBS electrodes in 0.9% NaCl exceeded the ± 50 mV range for on-board DC cancellation. We collected freely moving electrophysiological recordings from a Long-Evans rat to assess the bandpass filter performance on phase-locking accuracy in the theta (4-8 Hz) band. These in vivo results identified that improvements may be needed to increase the steepness of filter roll-off and stop-band attenuation of out-of-band (OOB) oscillations for accurate phase-locking in theta when significant OOB signals are present. The outcome of these experiments informs the design recommendations for the next-generation ASIC development, as part of the translational pathway of a novel phase-locked neurostimulation therapy for network-based psychiatric conditions.