A Scalable 256-Channel 12-mA 0.06%-Current-Mismatch 22-V Neurostimulator with Real-Time Current Calibration and Compliance Monitoring

Pulsed electrical stimulation (PES) is the gold standard for diagnostic [1] and therapeutic [2] applications, including functional and pathological mapping and treatment of neurological diseases with deep brain stimulation. Unfortunately, most clinical applications rely on electrode grid technologies with limited channels and poor spatial resolution. Recent advances, such as platinum nanorod electrode (PtNR) grids [3], hold the promise of PES with high channel counts, high spatial resolution, and enable heterogeneous electrode profiles (e.g., recording and stimulating contacts) in the same implant. However, new electronics are required to realize the benefits of such advanced grids. Specifically, electrical neurostimulators must simultaneously address new and challenging requirements, including a) high stimulation currents (>10mA) for electrodes of varying diameters; b) high electrode voltage compatibility (>20V) with real-time compliance monitoring; c) high channel counts (~100s) with low current mismatch <0.1%) across channels to improve stimulation focality; and d) cycle-by-cycle charge balancing to avoid electrode corrosion and tissue damage from residual charge build-up. These are the goals of this work.