64-Channel UWB Wireless Neural V ector Analyzer SOC With a Closed-Loop Phase Synchrony-Triggered Neurostimulator Karim Abdelhalim, Student Member , IEEE, Hamed Mazhab Jafari , Student Member , IEEE, Larysa Kokarovtseva, Jose Luis Perez V elazquez

Abstract

An ultra wideband (UWB) 64-channel responsive neural stimulator system-on-ch ip (SoC) is presented. It demon- strates the first on-chip neural vector analyzer capable of wire- lessly monitoring magnitude, phase and phase synchronization of neural signals. In a closed-loop, abnormal phase synchrony trig- gers the programmable-waveform biphasic current-mode neural stimulator. To implement these functionalities, the SoC integrates 64 neural recording ampli fiers with tunable switched-capacitor (SC) bandpass filters, 64 multiplying 8-bit SAR ADCs, 64 pro- grammable 16-tap FIR filters, a tri-core CORDIC processor, 64 biphasic current stimulation channels, and a 3.1–10.6 GHz UWB w i r e l e s st r a n s m i t t e ro n t oa4m m×3m m0 . 1 3µ mC M O Sd i e .T o minimize both the area and power dissipation of the SoC, the SAR ADC is re-used as a multiplier for FIR filtering and as a DAC and duty cycle controller for the biphasic neural stimulator. The SoC has been validated in the early detection and abortion of seizures in freely moving rodents on-line and in early seizure detection in humans off-line.