电刺激器的双极性输出及保护电路设计

目的为设计一种能够输出较为复杂波形的电刺激仪的双极性输出和保护电路。方法以单向置数方式的DAC和运放电路结合，实现双极性输出；以比较器LM311进行电压判断生成单片机中断信号而实现过压保护，以齐纳二极管实现限压，以三极管、二极管和电阻组合实现限流。使用Muhisim仿真工具，以保护电路为例对电压判断、限流限压电路进行了仿真试验。结果仿真实验表明本设计中输出保护电路实现了限流限压功能，该仪器实现了波形可编程的带有输出保护功能的双极性电刺激功能。结论该设计可实现双极性输出电刺激信号。并具有电路安全保护功能，达到了预期的目标。

Design of the bipolar outputs and protection drcuits in an electric stimulator

Objective This paper presents the design of bipolar output and protection circuits of an electric stimulator which can generate stimulating pulse with flexible parameters.Methods The common unipohr usage of DAC was combined with operational amplifier to generate bipolar output.The comparator LM311 was used to judge the output voltage and form an interrupt signal to accomplish over-voltage protection.The Zener diodes were apphed to limit the output voltage,and a circuit consisting of transistors,diodes and resistors was applied to limit the cttrrent.Simulation of the voltage-judging circuit,the current-limit and voltage-limit circuit were realized using Multisim simulation tool.Results The experiment data are coincident with the design well.The apparatus can perform the programmable function of bipolar electronic stimulation with current and voltage protection.Conclusion This design Can perform bipolar electrical output stimulation with circuit safety protection and well coincident with the design.