Abstract
This article proposes an inductor-charging switched-capacitor stimulation (iSCS) system capable of high-efficiency capacitor charging and high-efficacy decaying exponential stimulation. The iSCS system adopts a fast inductor-based charger with level-adaptive duty modulation and charging range detection that can efficiently charge capacitors from any residual voltage levels to the target voltages up to 3 V. The offset-control charge balancing (OC-CB) adaptively reduces the mismatch between cathodic and anodic charges. The iSCS prototype can charge 1-mu text{F} capacitor from 0 V (1.5 V) to 3 V within 50 μs (28μs), achieving 90% (92.7%) capacitor charging efficiency. The iSCS system efficiency was measured up to 92%, which is >10% higher than state-of-the-art works. The iSCS also achieved higher stimulus efficacy thanks to its decaying exponential waveform. In vivo experiments for ocular muscle stimulation using the iSCS system resulted in a 20% increase in eye movement distance while consuming 13% less energy compared to the current-controlled stimulation system. This ensures higher system efficiency and enhanced stimulus efficacy.
Original language | English |
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Pages (from-to) | 1521-1531 |
Number of pages | 11 |
Journal | IEEE Journal of Solid-State Circuits |
Volume | 59 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2024 May 1 |
Bibliographical note
Publisher Copyright:© 1966-2012 IEEE.
Keywords
- Capacitor charger
- implantable medical devices
- muscular stimulation
- offset-control charge balancing (OC-CB)
- switched-capacitor stimulation (SCS)
ASJC Scopus subject areas
- Electrical and Electronic Engineering