生物电放大电路的50 Hz干扰分析与电路设计(英文)  

Analysis of 50 Hz interference in the biopotential amplifier circuit and circuit design

作　　者：姬军[1] 俞梦孙[2] 

机构地区：[1]解放军第三0五医院,北京市100017 [2]解放军空军航空医学研究所,北京市100036

出　　处：《中国组织工程研究与临床康复》2008年第9期1782-1786,共5页Journal of Clinical Rehabilitative Tissue Engineering Research

基　　金：全军医学科学技术研究“十一五”计划课题(06MA364)~~

摘　　要：背景:在某些临床应用场合或特殊工作环境中,存在特别强烈的50Hz干扰,放大器的输出已经达到或接近饱和状态,一般的抗干扰电路和软件算法难以有效抑制。因此必须通过改进硬件电路抑制干扰以得到满意的信号。目的:介绍一种生物电放大器可以有效抑制50 Hz交流电干扰对微弱电生理信号检测的影响。设计:采用先进行理论分析,建立电路模型,再以软件仿真,最后设计实现实际应用电路。单位:解放军第三○五医院,空军航空医学研究所。材料:设计50 Hz交流电干扰的等效模型电路及电路仿真软件TINA RPO6.0均由空军航空医学研究所提供,高压电场实验环境由解放军第三○五医院提供的高压电场治疗仪制造。方法:首先在空军航空医学研究所进行理论分析,建立50 Hz干扰模型。提出下列三点抗干扰的措施,并应用在电路模型中:①提高整体电路共模输入阻抗以消除皮肤接触阻抗匹配失衡。②共模电压源控制恒流源降低仪表放大器等效共模输入阻抗。③右腿驱动电路减小共模电压。并且通过应用电路仿真软件TINA PRO对上述电路模型进行仿真分析。通过不断改进电路模型,获得正确的仿真结果。根据电路模型,设计实现了能够在强烈干扰环境下有效抑制50 Hz干扰的心电放大器。并在解放军第三○五医院高压电场治疗仪制造的强烈干扰环境下进行了实际使用,有效抑制了50 Hz干扰,获得高质量的心电信号。主要观察指标:通过电路共模抑制比和在强烈干扰环境下获得信号的频谱来评价抗50Hz交流干扰的能力。结果:为输入回路串接一个100 Ω和200 kΩ电阻以建立皮肤接触阻抗匹配失衡的状态。皮肤接触阻抗匹配失衡为100Ω时放大器在共模电压源的作用下,输出幅度为1.69mV峰峰值。根据计算,共模抑制比为125.8dB。皮肤接触阻抗匹配失衡为200 k Ω时放大器在共模电压源的作用下BACKGROUND： In some clinical applications or special work conditions, extremely intense 50 Hz AC interference exists. As the amplifier＇s output reaches or is close to saturation, it cannot be suppressed by general anti-interference circuits or software algorithms. Therefore, the hardware circuit must be improved to suppress this interference, thus obtaining the desired signals. OBJECTIVE： To introduce a biopotential amplifier, which can effectively suppress the impact of 50 Hz AC interference on the weak biomedical signals. DESIGN： Create a circuit model based on the advanced theoretical analysis, then make software emulation and finally design the actual circuit implementation. SETTINGS： the 305 Hospital of Chinese PLA; Institute of Aviation Medicine, Air Force of Chinese PLA. MATERIALS： The experimental instruments and analytical software were provided by the Institute of Aviation Medicine, Air Force of Chinese PLA; the high-voltage electrical field environment was provided by the 305 Hospital of Chinese PLA. METHODS： The first step was theoretical analysis at the Institute of Aviation Medicine, Air Fore of Chinese PLA in 2005, then the 50 Hz anti-reference model was created. After that, the following three anti-reference measures were put forward： （1） Enhancing the common-mode input impedance of the overall circuit to remove the interference caused by the imbalance electrode impedance; （2） reducing the equivalent common mode input impedance of the instrument amplifier in the circuit by using a current source controlled by the common mode voltage; （3） using the driven-right-leg circuit to reduce the common mode voltage. Moreover, emulation analysis was made for the above circuit model by using the circuit emulation software TINA PRO. Through ceaseless improvement of the circuit model, the correct emulation results were obtained. In 2006, the circuit model helped us realize the electrocardiogram （ECG） amplifier that could suppress the 50 Hz AC interference effectively in inten

关 键 词：50Hz交流电干扰 生物电放大器 共模抑制比 生物医学工程 

分 类 号：R318[医药卫生—生物医学工程]