EIT激励电流切换用模拟多路开关的选择  

Evaluation of Analog Multiplexers Used to Switch Excitation Current in EIT System

作　　者：张伟兴[1] 马艺馨[1] 

机构地区：[1]上海交通大学电子信息与电气工程学院仪器科学与工程系,上海200240

出　　处：《仪表技术与传感器》2013年第10期105-107,共3页Instrument Technique and Sensor

基　　金：上海市浦江人才计划(08PJ1406900);教育部博士点新教师基金项目(200802481011)

摘　　要：模拟多路开关作为电阻抗成像(EIT)数据采集系统的重要组成部分,用于切换激励电流到不同的电极对。然而实际模拟多路开关由于存在导通电阻和分布电容,对激励电流的分流影响随着频率升高而越来越显著。文中依据模拟多路开关的性能参数,建立EIT数据采集过程中激励电流通过模拟多路开关作用于人体的等效电路模型。结合ADG1206和MAX306两款模拟多路开关,对流经负载的电流进行频响分析,利用PSpice软件分别仿真测试了4种不同频率下激励电流在通过模拟开关之后所引起的电流损耗,分析总结了模拟多路开关的导通电阻和分布电容对EIT系统流过负载上的激励电流的影响,给出了在设计EIT数据采集系统时激励电流切换用模拟多路开关的选取依据。Analog multiplexer is an important component in EIT data acquisition system. It is used to switch the excitation cur- rent to different electrode pairs. However, the actual analog multiplexers have none-zero on/off-resistances and stray capacitances, their effect to the excitation current become more and more significant as the frequency increased. This paper, based on the perform- ance of analog multiplexer, established an equivalent circuit model of the exciting loop which included the current injection via ana- log multiplexers to the human body. The frequency response and simulation results using PSpice software demonstrate the current loss due to the impedance of analogue multiplexer ADG1206 or MAX306. The selection basis for the analog multiplexer used to switch the excitation current in EIT data system is summarized based on simulation results.

关 键 词：模拟多路开关 电阻抗成像 激励电流源 PSPICE仿真 电流损耗 

分 类 号：TN432[电子电信—微电子学与固体电子学]