An Energy-Efficient Stimulation System Based on Adaptive Dynamic Voltage Switching Control for Cochlear Implants

This paper presents the design and validation of a stimulation system for cochlear implants, addressing primary challenges in their power management, including variable supply conditions, multi-channel stimulation demands, and the necessity for swift, real-time data handling. The proposed stimulation system employs an adaptive dynamic voltage switching (ADVS) block and a single-inductor multiple-output (SIMO) boost converter to generate and selectively assign optimal voltage levels to each stimulation channel. This strategic selection, governed remotely via an external sound processor and adaptively controlled by a compliance monitoring circuit, facilitates dynamic voltage adjustments within sub-$\mu$s, enhancing system responsiveness and energy efficiency. Fabricated in a 180-nm BCD process, the system's functionality and efficiency have been validated by measurements, showing an enhancement in battery life up to 13.5$\%$ which translates into an extra 3.4 hours of operational time. Through the integration of ADVS, the proposed system not only enhances the performance of cochlear implants, but also ensures the adaptability and effectiveness in real-world environments.