生物阻抗谱多频激励信号设计方法研究  

Design method of biological impedance spectrum multi-frequency excitation signal

作　　者：杜强[1] 吕海明 柯丽[1] 张智 DU Qiang;LYU Hai-ming;KE Li;ZHANG Zhi(School of Electrical Engineering,Shenyang University of Technology,Shenyang 110870,China)

机构地区：[1]沈阳工业大学电气工程学院,沈阳110870

出　　处：《医疗卫生装备》2020年第9期1-8,共8页Chinese Medical Equipment Journal

基　　金：辽宁省自然科学基金计划项目(2019-ZD-0204)。

摘　　要：目的:设计一种人体生物阻抗谱多频同步激励信号,解决传统多频正弦信号波峰因数高、激励能量低、测量精度低等问题。方法:基于生物阻抗谱测量原理与激励信号设计原则,设计离散二值多频激励信号代替传统多频正弦信号。结合人体生物阻抗频响特性,研究信号幅频参数设计方法,并设计基于双边函数的频率点分布和高频段激励信号幅值补偿方案。利用MATLAB软件对信号频谱特性、激励能量、波峰因数、信噪比进行计算分析,并仿真测试在不同测量条件下信号的测量误差与信噪比。最后搭建测试平台,使用Cole模型进行实测分析,并与多频正弦信号测试结果进行对比。结果:该激励信号频谱特征符合预期设计,波峰因数为1.25,主谐波功率占比达到63.71%,激励能量约为多频正弦信号的2倍。仿真测试中,该激励信号在-55^-15 dB噪声环境下,平均测量误差最大不超过4.89%,在不同采样精度条件下信噪比均高于多频正弦信号约10 dB。Cole模型实测中,该激励信号测量阻抗模值误差最大不超过1.09%,相位误差最大不超过0.46°,拟合后Cole模型参数平均误差仅为6.12%,均低于多频正弦信号测量结果。结论:相较于传统多频正弦信号,该激励信号更加适用于人体生物阻抗谱多频同步测量。Objective To design a multi-frequency synchronous excitation signal of human bioimpedance spectrum to solve the problems of traditional multi-frequency sinusoidal signal in high wave crest factor,low excitation energy and low measurement accuracy.Methods A discrete binary multi-frequency excitation signal was designed to replace the traditional multi-frequency sinusoidal signal based on the measurement principle of bioimpedance spectrum and the excitation signal design principle.A design method was studied for signal amplitude and frequency parameters combined with the human bioimpedance frequency response characteristics,and a compensation scheme was proposed for the bilateral-function-based frequency point distribution and high frequency band excitation signal amplitude.MATLAB software was used to calculate and analyze the signal spectral characteristics,excitation energy,wave crest factor and signal-to-noise ratio,and to simulate the measurement error and signal-to-noise ratio under different measurement conditions.Finally,a test platform was built and the Cole model was used for measurement and analysis,and the results were compared with those of multi-frequency sine signals.Results The spectral characteristics of the excitation signal conformed to the desired requirements,the wave crest factor was 1.25,the main harmonic power ratio reached 63.71%,the excitation energy was about twice as much as the multi-frequency sine signal.In the simulation test,under the environment of-55 to-15 dB noise,the average measurement error was no more than 4.89%,and the signal-to-noise radio was higher than the multi-frequency sinusoidal signal by about 10 dB under different sampling accuracy conditions.In the Cole model,the maximum impedance modulus error was less than 1.09%,the maximum phase error was less than 0.46°,and the average error of Cole model parameters was only 6.12%,which was lower than that of the multi-frequency sine signal.Conclusion Compared with traditional multi-frequency sinusoidal signals,this excitation

关 键 词：生物阻抗谱 多频同步激励 幅频特性 波峰因数 激励能量 离散二值多频激励信号 

分 类 号：R318[医药卫生—生物医学工程] R318.04[医药卫生—基础医学]