家兔红细胞阻抗谱的实验和等效电路拟合研究

Studies on Experimental and Equivalent Circuit Fitting of the Rabbit Erythrocytes Impedance Spectra

目的:研究家兔红细胞阻抗谱并建立RC等效电路模型参数。方法:在0.01MHz^100MHz频率范围,使用Agilent 4294A阻抗分析仪测量了家兔红细胞交流阻抗,通过Bode图、Nyquist图、Nicols图、Randles图的曲线拟合分析,比较三个RC等效电路模型的拟合残差。结果:(1)家兔红细胞阻抗谱的第一特征频率fc1=2.5MHz,第二特征频率fc2=5.25MHz;(2)等效电路模型,模型3的拟合误差小于模型1和模型2;(3)等效的单个红细胞膜电容约为0.458μF/cm2。结论:家兔红细胞阻抗谱表现出两个特征频率,其等效电路模型以模型3形式更为合理。

Objective： To study impedance spectra of rabbit erythrocytes, and establish its equivalent circuit model parameters. Method： The AC impedance of rabbit erythrocytes have been measured with the Agilent 4294A impedance analyzer at frequency range of 0.01MHz～100MHz, then curve fitting residual error of rabbit erythrocyte＇ s equivalent circuit have been compared by the Bode plot,the Nyquist plot, the Nicols plot and the Randles plot. Results： 1）The characteristic 1^st frequency （fcl） was 2.5MHz, the characteristic 2^nd frequency （fc2） was 5.25MHz for impedance spectra of rabbit erythrocytes; 2）Curve fitting residual error of equivalent circuit of model-3 was less than those of model-1 and model-2; 3）The membrane capacitance of equivalent single erythrocyte was about 0.458μF/cm2. Conclusion：The impedance spectra of rabbit erythrocytes have presented two characteristic frequency （fc1 ,fc2）,and model-3 is one of the most appropriate equivalent circuit models.