电容耦合非接触电极及心电信号获取.docxVIP

第36卷第5期 第36卷第5期 仪 器 仪 表 学 报 VoL 36 No．5 2015年5月 Chinese Journal of Scientific Instrument May．2015 电容耦合非接触电极及心电信号获取木 杨斌，董永贵 (清华大学精密仪器系精密测试技术及仪器国家重点实验室北京100084) 摘要：电极与皮肤间接触所导致的不适感，是穿戴式心电信号测量系统实际应用中的常见问题。设计了一种非接触心电信号 测量系统。采用印刷电路板制作的测量电极，借助电容耦合测量位移电流的方式获取心电信号。采用反接二极管提供测量所 需的高阻值偏置电阻，结合高输入阻抗仪表放大器，制作了测量电极信号提取电路。测量系统由两个测量电极与一个直接与测 量电路地相连的参考电极组成。选择金属铝板、导电纤维和导电橡胶作为参考电极，实验研究了共模干扰抑制性能与参考电极 接触阻抗之问的量化关系。将主元分析与奇异谱分析相结合，提出了一种心电信号处理算法。实验结果表明，该系统可在棉质 线衣外侧有效获得满意的心电信号。 关键词：心电信号；电容耦合电极；可穿戴器件；主元分析；奇异谱分析 中图分类号：TH776 文献标识码：A 国家标准学科分类代码：310．61 Capacitive coupled non—contact electrodes and ECG signal acquisition Yang Bin，Dong Yonggui (State Key Laboratory of Precision．Measurement Technology and Instruments，Department of Prec玉ion Instrument，Tsinghua University，Bering 100084，China) Abstract：In practical applications of wearable electrocardiogram(ECG)monitoring systems，the disconffortness caused by the be— tween the electrodes and skin is common problem．A／Ion—contact ECG measurement system is designed．The sensing electrodes made from standard printed circuit board(PCB)．The ECG signal is obtained by means of displacement measurement in capacitive pling way．A reversely connected diode is used provide the required high—value bias resistance for the measurement；the pickup circuit for the measurement electrode is implemented with high input impedance instrumentation amplifier．The measurement system is composed of two measurement electrodes．together with reference electrode that is directly connected the measurement circuit ground．muIIli— nun plate，conductive textile，and conductive polymer are selected as the reference electrode，respectively．The relationship between the common—mode interference suppression performance and the contact impedance of the reference electrode is analyzed quantitatively in exper— iment．A New ECG signal processing algorithm，which combines principal com