A Reconfigurable Neural Stimulation IC With a High-Resolution Strength Control and In-Situ Neural Recording Function for Cochlear Implant Systems

This letter presents a neural stimulation IC for the 32-channel cochlear implant system. A zoom current DAC (I-DAC), whose full range is reconfigured to fit the interval between the comfort (C) and threshold (T) levels, is introduced for high-resolution stimulation strength control to provide high-fidelity sound perception with minimal hardware overhead. The IC also includes an in-situ neural recording function. The effectiveness of auditory nerve stimulation is validated by monitoring electrically evoked compound action potential (ECAP) in-vivo using a rat model. It is found that the action potential amplitude increases as the stimulation current level becomes larger.