Design of a Bone-Guided Cochlear Implant Microsystem With Monopolar Biphasic Multiple Stimulations and Evoked Compound Action Potential Acquisition and Its In Vivo V erification

Abstract

A CMOS bone-guided cochlear implant (BGCI) microsystem is proposed and verified. In the implanted Sys- tem on Chip (SoC) of the proposed BGCI, the evoked com- pound action potential (ECAP) acquisition and electrode–tissue impedance measurement (EAEIM) circuit is integrated to mea- sure both ECAP and electrode–tissue impedance for clinical diagnoses. Both positive-/negative-voltage charge pumps and monopolar biphasic constant-current stimulation (CCS) stimu- lator are designed on-chip to realize monopolar biphasic CCS or double-electrode multiple stimulations with a maximum stim- ulation current of 1.2 mA and a step of 10 µA. With the double-electrode multiple stimulations, the electric field can be shifted and localized under the stimulating electrode to stimulate the auditory nerves. The wireless bilateral data telemetry circuits with a full-wave active rectifier and the pulsed load-shift keying (PLSK) modulators/demodulators are designed for power and Manuscript received January 11, 2021; revised April 21, 2021; accepted June 1, 2021. Date of publication June 21, 2021; date of current version September 24, 2021. This article was approved by Associate Editor Jun Deguchi. This work was supported in par t by the Center for Neuromodulation Medical Electronics Systems from The Featured Areas Research Center Program within the framework of th e Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan and in part by the Ministry of Science and Technology (MOST), T