Lateva Z C, Dimitrov G V, Dimitrova N A
Bulgarian Academy of Sciences, CLBA, Sofia.
Med Biol Eng Comput. 1990 Nov;28(6):537-43. doi: 10.1007/BF02442604.
The power spectra of bipolarly recorded extracellular action potentials (EAPs) generated by an infinite, homogeneous, excitable fibre in an infinite, resistive, isotropic and homogeneous volume conductor were theoretically analysed. The changes in the power spectrum of EAP, which occurred as a result of alterations in the propagation velocity v and duration Tin of the intracellular action potential IAP, were analytically determined for bipolar parallel and radial electrodes with a small interpole distance. It was found that the sensitivity of the spectral characteristics to alterations in v, Tin and/or the IAP asymmetry substantially depends on the fibre-electrode distance; information on the IAP fast changes, that seems to be lost in unipolar recording as a result of the filtering effect of the fibre-electrode distance, can be restored. The orientation of the recording electrode need not be taken into account when a qualitative analysis is carried out, but when a quantitative analysis has to be performed, then the electrode orientation has a significant influence. A method is suggested for determination of the fibres' orientation by means of the spectrum of EAPs recorded bipolarly. The selectivity of the bipolar electrodes is analysed.
对无限大、均匀、可兴奋纤维在无限大、电阻性、各向同性且均匀的容积导体中产生的双极记录细胞外动作电位（EAP）的功率谱进行了理论分析。对于极间距离较小的双极平行电极和径向电极，分析确定了由于细胞内动作电位（IAP）的传播速度v和持续时间Tin的改变而导致的EAP功率谱的变化。发现频谱特性对v、Tin和/或IAP不对称性改变的敏感度很大程度上取决于纤维-电极距离；由于纤维-电极距离的滤波作用，单极记录中似乎丢失的IAP快速变化的信息可以恢复。进行定性分析时无需考虑记录电极的方向，但进行定量分析时，电极方向有显著影响。提出了一种通过双极记录的EAP频谱确定纤维方向的方法。分析了双极电极的选择性。
