Yang Yuxiang, Zhang Fu, Tao Kun, Wang Lianhuan, Wen He, Teng Zhaosheng
Department of Precision Instrumentation Engineering, Xi'an University of Technology, Xi'an, People's Republic of China.
Physiol Meas. 2015 Mar;36(3):489-501. doi: 10.1088/0967-3334/36/3/489. Epub 2015 Feb 13.
Bioimpedance spectroscopy (BIS) is becoming a powerful diagnostic tool for a wide variety of medical applications, and the multi-frequency simultaneous (MFS) measurement of BIS can greatly reduce measurement time and record the transient physiological status of a living body compared with traditional frequency-sweep measurement technology. This paper adopts the Van der Ouderaa's multisine, which has 31 equidistant and flat amplitude spectra and a low crest factor of 1.405 as the broadband excitation, and realizes the MFS measurement of BIS by means of spectral analysis using the fast Fourier transform algorithm. The approach to implement the multisine based on a field-programmable gate array and a digital to analog converter is described in detail, and impedance measurement experiments are performed on three resistance-capitance three-element phantoms. Experimental results show a commendable accuracy with a mean relative error of 0.55% for the impedance amplitudes, and a mean absolute error of 0.20° for the impedance phases on the 31 frequencies ranging linearly from 32 to 992 kHz. This paper validates the feasibility of the MFS technology for BIS measurement based on the multisine excitation.
生物电阻抗谱（BIS）正成为用于多种医学应用的强大诊断工具，与传统的扫频测量技术相比，BIS的多频同步（MFS）测量可以大大减少测量时间并记录活体的瞬态生理状态。本文采用具有31个等距且平坦幅度谱以及1.405的低波峰因数的范德奥德拉伸多正弦波作为宽带激励，并通过使用快速傅里叶变换算法的频谱分析实现BIS的MFS测量。详细描述了基于现场可编程门阵列和数模转换器实现多正弦波的方法，并在三个电阻 - 电容三元模型上进行了阻抗测量实验。实验结果表明，在32至992 kHz线性范围内的31个频率上，阻抗幅度的平均相对误差为0.55%，阻抗相位的平均绝对误差为0.20°，具有令人满意的精度。本文验证了基于多正弦波激励的MFS技术用于BIS测量的可行性。
