A CMOS Current Steering Neurostimulation Array With Integrated DAC Calibration and Charge Balancing.
A CMOS Current Steering Neurostimulation Array With Integrated DAC Calibration and Charge Balancing.
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DOI：
10.1109/tbcas.2016.2609854
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发表时间：
2017-04
影响因子：
5.1
通讯作者：
Thakor N
中科院分区：
文献类型：
--
作者：
Greenwald E;Maier C;Wang Q;Beaulieu R;Etienne-Cummings R;Cauwenberghs G;Thakor N
提出了一种具有片上电流DAC校准和残差零的8通道电流可控多相神经刺激器，用于精确电荷平衡。每个通道由两个亚二进制基数dac组成，然后是宽摆幅，高输出阻抗电流缓冲器，为阳极和阴极刺激提供时间复用的源和汇输出。单个积分器在通道之间共享，用于校准DAC系数，并密切匹配阳极和阴极刺激相。校准后，在8位分辨率下，差分非线性在±0.3 LSB范围内，两个刺激阶段的匹配度在0.3%范围内。通过数字编程对整个阵列的增产系数进行单独控制，可以通过电流转向来改变当前增产的空间剖面，从而选择增产目标。结合自校准和电流匹配功能，当前的转向能力集成在芯片上，支持完全植入的神经接口，在电极和组织条件的变化下自主操作和自适应刺激。作为概念验证，我们通过多通道袖带电极在大鼠坐骨神经上应用电流转向刺激。
An 8-channel current steerable, multi-phasic neural stimulator with on-chip current DAC calibration and residue nulling for precise charge balancing is presented. Each channel consists of two sub-binary radix DACs followed by wide-swing, high output impedance current buffers providing time-multiplexed source and sink outputs for anodic and cathodic stimulation. A single integrator is shared among channels and serves to calibrate DAC coefficients and to closely match the anodic and cathodic stimulation phases. Following calibration, the differential non-linearity is within ± 0.3 LSB at 8-bit resolution, and the two stimulation phases are matched within 0.3%. Individual control in digital programming of stimulation coefficients across the array allows altering the spatial profile of current stimulation for selection of stimulation targets by current steering. Combined with the self-calibration and current matching functions, the current steering capabilities integrated on-chip support use in fully implanted neural interfaces with autonomous operation for and adaptive stimulation under variations in electrode and tissue conditions. As a proof-of-concept we applied current steering stimulation through a multi-channel cuff electrode on the sciatic nerve of a rat.