Inductively-powered direct-coupled 64-channel chopper-stabilized epilepsy-responsive neurostimulator with digital offset cancellation and tri-band radio

An inductively powered 0.13μm CMOS neurostimulator SoC for intractable epilepsy treatment is presented. Digital offset cancellation yields a compact 0.018mm² DC-coupled neural recording front-end. Input chopper stabilization is performed on all 64 channels resulting in a 4.2μVrms input-referred noise. A tri-band FSK/UWB radio provides a versatile transcutaneous interface. The inductive powering system includes a 20mm × 20mm 8-layer flexible receiver coil with 40% power transfer efficiency. In-vivo chronic epilepsy treatment experimental results show an average sensitivity and specificity of seizure detection of 87% and 95%, respectively, with over 76% of all seizures aborted.