Abstract
A power-efficient wireless stimulating system for a head-mounted deep brain stimulator (DBS) is presented. A new adaptive rectifier generates a variable DC supply voltage from a constant AC power carrier utilizing phase control feedback, while achieving high AC-DC power conversion efficiency (PCE) through active synchronous switching. A current-controlled stimulator adopts closed-loop supply control to automatically adjust the stimulation compliance voltage by detecting stimulation site potentials through a voltage readout channel, and improve the stimulation efficiency. The stimulator also utilizes closed-loop active charge balancing to maintain the residual charge at each site within a safe limit, while receiving the stimulation parameters wirelessly from the amplitude-shift-keyed power carrier. A 4-ch wireless stimulating system prototype was fabricated in a 0.5-μm 3M2P standard CMOS process, occupying 2.25 mm2. With 5 V peak AC input at 2 MHz, the adaptive rectifier provides an adjustable DC output between 2.5 V and 4.6 V at 2.8 mA loading, resulting in measured PCE of 72 ~ 87%. The adaptive supply control increases the stimulation efficiency up to 30% higher than a fixed supply voltage to 58 ~ 68%. The prototype wireless stimulating system was verified in vitro.
Original language | English |
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Article number | 6584038 |
Pages (from-to) | 2203-2216 |
Number of pages | 14 |
Journal | IEEE Journal of Solid-State Circuits |
Volume | 48 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2013 |
Externally published | Yes |
Keywords
- Active charge balancing
- Adaptive rectifier
- Closed-loop supply control
- Head-mounted deep brain stimulation
- Implantable medical devices
- Inductive power transfer
ASJC Scopus subject areas
- Electrical and Electronic Engineering