大鼠腓肠肌细胞介电谱测量和Cole-Cole数学模型分析

The Measurement and Cole-Cole Mathematical Model Analysis on Dielectric Spectra of Rat Gastrocnemius Cells

测量大鼠腓肠肌细胞介电谱,利用Cole-Cole方程的曲线拟合建立Cole-Cole数学模型参数。在100 Hz^100MHz频率范围,使用Agilent 4294A阻抗分析仪对电场与肌纤维方向呈平行和垂直的大鼠腓肠肌进行了阻抗测量,并利用Cole-Cole方程的数值计算,对细胞介电谱、Cole-Cole图、介电损耗因子频谱、电导率虚部频谱和损耗角正切频谱进行曲线拟合分析和残差分析,比较电场与肌纤维方向呈平行或垂直两种情况的介电行为区别。结果表明:骨骼肌细胞的介电弛豫具有两个特征频率,其平行方向的特征频率低于垂直方向;平行方向的介电增量高于垂直方向的介电增量;平行方向的低频极限量高于垂直方向的低频极限量;平行方向和垂直方向的介电常数高频极限量相等;平行方向和垂直方向的电导率高频极限量存在一定差距。平行方向的电导率虚部频谱和损耗角正切分别高于垂直方向的值,但是,平行方向的电导率虚部最大值低于其垂直方向的值。腓肠肌细胞的介电常数和电导率存在频率依存性和各向异性,其介电行为存在α和β两个介电散射,并满足Cole-Cole数学模型。

The dielectric spectroscopy of rat gastrocnemius cells were measured and its Cole-Cole model parameters were established with curve fitting. The AC impedance of rat gastrocnemius were measured with the Agilent 4294A impedance analyzer at frequencies between 100Hz and 100MHz, with the tissue samples oriented either parallel or perpendicular to the direction of the applied electric field. The curve fitting and residual error were numerically calculated with Cole-Cole formula. The difference of dielectric behaviors in the parallel and the perpendicular orientation was compared with cell dielectric spectroscopy, Cole-Cole plots, loss factor, imaginary part of conductivity and loss tangent. The dielectric dispersion of skeletal muscle cells had two characteristic frequencies, and the characteristic frequency in the parallel orientation was lower than that in the perpendicular orientation; The dielectric increment in the parallel orientation was higher than that in the perpendicular orientation; The low-frequency limit in the parallel orientation was higher than that in the perpendicular orientation; The high-frequency limit of relative permittivity was the same in the parallel and the perpendicular orientation; The high-frequency limit of conductivity demostnated some differences in the parallel and the perpendicular orientation; The maximum imaginary part of cell dielectric spectroscopy and the maximum loss tangent in the parallel orientation were higher than that in the perpendicular orientation, but the maximum imaginary part of conductivity in the parallel orientation was lower than that in the perpendicular orientation. The permittivity and the conductivity of gastrocnemius ceils have frequency dependence and anisotropy, and their dielectric behavior has a and β dispersions, which have been proved to fit the Cole-Cole mathematical model.