Intracochlear Electric and Acoustic Stimulator Prototype: An Implantable Solution to the Hybrid Cochlear Implant

This paper reports an intracochlear electric and acoustic stimulator (EAS) prototype, which adopted the board-level integration of a piezoelectric micro-actuator and a thin film electrode array. The EAS prototype meets the cochlear size limitations, with its implant part having a maximum diagonal dimension of <; 1.5 mm, and a 21-mm-long electrode array complying with the first cochlear turn. When the electric and acoustic stimulators work simultaneously, the amplitude of the interfering stimulus' frequency component accounts for <; 2% of the base frequency component. Compared to the state of the art in the hybrid cochlear implant, for the first time, the prototype proved the feasibility of intracochlear hybrid stimulation with an integrated stimulator. The EAS prototype represents a promising solution to improve the patients' wearing comfort and application scenarios.