64-Channel UWB Wireless Neural Vector Analyzer and Phase Synchrony-Triggered Stimulator SoC

Abstract — A UWB 64-channel responsive neural stimulator is presented. It wirelessly monitors magnitude, phase and phase synchronization of neural signals. Abnormal phase synchrony triggers programmable-waveform biphasic current-mode stim-ulation in a closed loop. To implement these functionalities, the SoC integrates 64 neural recording amplifiers with tunable switched-capacitor (SC) bandpass filters, 64 multiplying 8-bit SAR ADCs, 64 programmable 16-tap FIR filters, a tri-core CORDIC processor, 64 biphasic current stimulation channels, and a 3.1-10.4GHz UWB wireless transmitter onto a 4mm × 3mm 0.13µm CMOS die. The SoC dissipates 1.4mW/1.5mW when recording/stimulating and has been validated in early detection and abortion of epileptic seizures in freely moving rodents on-line and in early seizure detection in humans off-line. I