FPGA多通道视皮层刺激器

Multi-channel cortical stimulator based on FPGA

设计了一款用于视皮层视觉修复的基于FPGA的多通道视皮层刺激器。该刺激器由FPGA和外围电压/电流转换电路两部分组成。FPGA内部包括刺激脉冲发生器和多个多路选择器:刺激脉冲发生器产生各种形式的脉冲序列信号;多路选择器作为控制端实现对信号的选择,每一通道对应一个多路选择器,增加多路选择器即可实现通道的增加。FPGA输出的电压信号通过外围电压/电流转换电路,转换为电流信号后传入电极阵列。采用Altera公司Cyclone系列EP1C6型FPGA制作了四通道实验样机进行动物实验。采用猫作为实验对象,在猫的视皮层硬脑膜外左右两侧植入微电极,左侧接入刺激信号,右侧记录脑电,实验结果显示,视皮层能够响应来自对硬脑膜的电刺激,验证了所设计的刺激器是可行的。

A FPGA based multi-channel cortical stimulator system for cortical visual prosthesis was designed.devised for generating a sequence of electrical pulses for cortical stimulation.The simulator is composed of a FPGA and voltage/current converters.The FPGA comprises a spike generator to generate various electrical pulse sequences and some multiplexers to select signals.The prototype based on an Altera Cyclone EP1C6 FPGA with four channels is developed to perform the experimental evaluation.Two electrode chips ane put out of the left and right dura of cortex of a cat.The electrical stimulation is connected to the left one,while the visual electrically evoked potential（EEP） is recorded by the right one.The experimental results on cat＇s cortex show that the cortex can respond to the current stimulation.