多频率激励生物电阻抗测量方法的研究

Research of a Bio_electrical Impedance Measurement Based on Multi-Frequency Technology

摘要:

生物电阻抗是生物组织的一个重要电参数,对生物电阻抗的测量与分析在生物医学工程上有着重要的研究和应用价值；采用四电极测量法,设计了一种多频激励的生物电阻抗测量系统,利用AFE4300产生16-128 kHz激励信号源,并将此激励信号施加于待测生物组织上,通过IQ解调,得出待测电阻抗的模值和相角；当激励信号为128 kHz时,系统模值测量误差最大,最大测量误差为2.07%,且随着激励频率的增加,模值和相角的测量误差呈逆向变化趋势,在不同的应用场合,选择不同的激励频率可以提高生物电阻抗的测量精度。

Abstract:

Bio_electrical impedance is an important electrical parameter of biology tissue,bio_electrical impedance measurement and analysis has important research and application value on the bio_medical engineering。Using four electrode method,designing a multi-frequency excitation bio_electrical impedance measurement system,making use of AFE4300 produce 16-128 kHz adjustable excitation signal source,putting the current electrodes on the test of biological tissue, through the IQ demodulation, can calculate the measured impedance modulus value and angle .When the excitation signal is 128 kHz, the system has the maximum error,the error is 2.07%.And with the increase of excitation frequency, modulus and phase Angle measurement error reverse the trend so that in different applications, choose different excitation frequency can improve the measurement precision of the system.