Nag Sudip, Jia Xiaofeng, Thakor Nitish V, Sharma Dinesh
Electrical Engineering Department, Indian Institute of Technology Bombay, IIT Powai, Mumbai, Maharashtra 400076, India.
IEEE Trans Biomed Circuits Syst. 2013 Jun;7(3):266-75. doi: 10.1109/TBCAS.2012.2205574.
Electrical stimulations of neuronal structures must ensure net injected charges to be zero for biological safety and voltage compliance reasons. We present a novel architecture of general purpose biphasic constant current stimulator that exhibits less than 5.6 fC error while injecting 140 nC charges using 1.4 mA currents. The floating current sources and conveyor switch based system can operate in monopolar or bipolar modes. Anodic-first or cathodic-first pulses with optional inter-phase delays have been demonstrated with zero quiescent current requirements at the analog front-end. The architecture eliminates blocking capacitors, electrode shorting and complex feedbacks. Bench-top and in-vivo measurement results have been presented with emulated electrode impedances (resistor-capacitor network), Ag-AgCl electrodes in saline and in-vivo (acute) peripheral nerve stimulations in anesthetized rats.
出于生物安全性和电压适应性的考虑，对神经元结构进行电刺激时必须确保净注入电荷为零。我们提出了一种新型的通用双相恒流刺激器架构，该刺激器在使用1.4 mA电流注入140 nC电荷时，误差小于5.6 fC。基于浮动电流源和传送器开关的系统可以在单极或双极模式下运行。已经证明，在模拟前端零静态电流要求的情况下，可以产生具有可选相间延迟的阳极优先或阴极优先脉冲。该架构消除了隔直电容、电极短路和复杂的反馈。本文给出了在模拟电极阻抗（电阻-电容网络）、盐水中的Ag-AgCl电极以及麻醉大鼠体内（急性）外周神经刺激情况下的台式和体内测量结果。
