Chun Hosung, Tran Nhan, Yang Yuanyuan, Kavehei Omid, Bai Shun, Skafidas Stan
Department of Electrical and Electronic Engineering, University of Melbourne, Melbourne, Australia.
Annu Int Conf IEEE Eng Med Biol Soc. 2012;2012:3001-4. doi: 10.1109/EMBC.2012.6346595.
In this paper, we present a precise charge balancing and compliance voltage monitoring stimulator front-end for 1024-electrode retinal prosthesis. Our stimulator is based on current mode stimulation. To generate a precisely matched biphasic current pulse, a dynamic current copying technique is applied at the stimulator front-end. A compliance voltage monitoring circuitry is included at the stimulator front-end to detect if a voltage across electrode-tissue interface goes beyond a predefined compliance voltage. Simulation results show the mismatch of a biphasic current pulse (at a maximum stimulation current of 476µA) is less than 0.1%. Also, the stimulator issues alarm signals, when a voltage compliance occurs during stimulation due to high tissue impedance. Our stimulator is implemented using a 65nm low voltage (LV) CMOS process, which helps reducing implementation area and power consumption.
在本文中，我们提出了一种用于1024电极视网膜假体的精确电荷平衡和合规电压监测刺激器前端。我们的刺激器基于电流模式刺激。为了生成精确匹配的双相电流脉冲，在刺激器前端应用了动态电流复制技术。刺激器前端包含一个合规电压监测电路，以检测电极-组织界面上的电压是否超过预定义的合规电压。仿真结果表明，双相电流脉冲（在最大刺激电流为476µA时）的失配小于0.1%。此外，当由于高组织阻抗在刺激期间出现电压合规情况时，刺激器会发出警报信号。我们的刺激器采用65nm低电压（LV）CMOS工艺实现，这有助于减小实现面积和功耗。
