生物电阻抗扫描成像系统前置级检测电路的扩频优化设计  

Spread spectrum optimization design of front-end detection circuit for electrical impedance scanning system

作　　者：张坤 马航 檀旸 丁晗 李嘉旎 季振宇 ZHANG Kun;MA Hang;TAN Yang;DING Han;LI Jia-ni;JI Zhen-yu(The 986th Hospital of Air Force,Xi'an 710029,China;Department of Medical Electronic Engineering,Military Biomedical Engineering School of Air Force Medical University,Xi'an 710032,China;Shaanxi Key Laboratory for Bioelectromagnetic Detecting and Intelligent Sensing of Air Force Medical University,Xi'an 710032,China)

机构地区：[1]空军第986医院,西安710029 [2]空军军医大学军事生物医学工程学系医学电子工程教研室,西安710032 [3]空军军医大学生物电磁检测与智能感知陕西省重点实验室,西安710032

出　　处：《医疗卫生装备》2023年第2期31-36,共6页Chinese Medical Equipment Journal

基　　金：国家重点研发计划项目(2019YFC0119103);国家自然科学基金面上项目(81671846)。

摘　　要：目的:针对生物电阻抗扫描成像(electrical impedance scanning,EIS)宽频谱测量的需求,对使用手持式检测探头的EIS系统的前置级检测电路进行扩频优化设计。方法:首先,基于电流/电压转换电路、二选一模拟开关实现EIS系统前置级64通道检测电路的拓扑结构设计。其次,对实现电流/电压转换电路的集成运算放大器芯片和二选一模拟开关芯片进行选型优化,并完成印制电路板制作。最后,对优化后的电路的频率响应、输出信号的通道干扰、信噪比等关键指标进行测试。结果:在100 Hz~500 kHz的工作频率内,优化后的电路的增益稳定度在0.015以内,最大相移小于1.8°,通道串扰低于-62 dB,输出信号信噪比高于65 dB。结论:优化后的前置级检测电路在100 Hz~500 kHz工作频率范围内能够满足EIS检测的精度需求,为开展宽频谱EIS研究提供了硬件基础。Objective To carry out spread spectrum optimization design of the front-end detection circuit for the electrical impedance scanning(EIS)system with a hand-held probe.Methods The topology design of the EIS system front-end 64-channel detection circuit was implemented based on current/voltage conversion circuits and bidirectional analog switches.Then the chips for integrated operational amplifier and bidirectional analog switch were selected for obtaining the current/voltage conversion circuit to fabricate a printed circuit board.Finally the key indicators of the optimized circuit were tested including frequency response,channel interference of output signals and signal-to-noise ratio.Results Within the operating frequency of 100 Hz to 500 kHz the optimized circuit had the gain stability lower than 0.015,the maximum phase shift less than 1.8°,the channel crosstalk lower than-62 dB and the output signal-to-noise ratio higher than 65 dB.Conclusion The optimized front-end detection circuit meets the accuracy requirements of EIS detection in the operating frequency range from 100 Hz to 500 kHz,which provides a hardware foundation for the broad-spectrum EIS research.

关 键 词：EIS 前置级检测电路 生物电阻抗 电阻抗成像 多频电阻抗成像 

分 类 号：TH79[机械工程—仪器科学与技术]