A High-Resolution Opto-Electrophysiology System With a Miniature Integrated Headstage

This work presents a fully integrated neural interface system in a small form factor (1.9 g), consisting of a μLED silicon optoelectrode (12 μLEDs and 32 recording sites in a 4-shank configuration), an Intan 32-channel recording chip, and a custom optical stimulation chip for controlling 12 μLEDs. High-resolution optical stimulation with approximately 68.5 nW radiant flux resolution is achieved by a custom LED driver ASIC, which enables individual control of up to 48 channels with a current precision of 1 μA, a maximum current of 1.024 mA, and an update rate of >10 kHz. Recording is performed by an off-the-shelf 32-channel digitizing front-end ASIC from Intan. Two compact custom interface printed circuit boards were designed to link the headstage with a PC. The prototype system demonstrates precise current generation, sufficient optical radiant flux generation (Φ
_e
> 0.16 μW), and fast turn-ON of μLEDs (
t
_rise
<; 10 μs). Single animal in vivo experiments validated the headstage's capability to precisely modulate single neuronal activity and independently modulate activities of separate neuronal populations near neighboring optoelectrode shanks.