Institute of General Electrical Engineering, University of Rostock, D-18051 Rostock, Germany.
Institute of General Electrical Engineering, University of Rostock, D-18051 Rostock, Germany; Department Life, Light & Matter, University of Rostock, D-18051 Rostock, Germany; Department of Ageing of Individuals and Society, Interdisciplinary Faculty, University of Rostock, D-18051 Rostock, Germany.
Bioelectrochemistry. 2021 Aug;140:107773. doi: 10.1016/j.bioelechem.2021.107773. Epub 2021 Feb 24.
The frequency-dependent behaviour of the dielectric properties of biological tissues in the frequency range below 1 kHz has been under debate since the past century. Here, we reanalyse the raw data of the main resource of the dielectric properties of biological tissues in impedance representation. Employing a Kramers-Kronig validity test and parameter estimation techniques, we can describe the data by two physical parametric models that correspond to opposing biophysical interpretations: on the one hand the data can be explained only by intrinsic tissue properties, but on the other hand evidence for electrode-specific effects can be found for all tissues under investigation. The first interpretation would justify the continued use of a parametric model comprising four Cole-Cole dispersions, which describe the dielectric properties from extremely low to very high frequencies. As an alternative that is in accordance with the second interpretation, we suggest to omit the slowest of the four dispersions in the model and increase the static conductivity to account for a frequency-independent conductivity below 1 kHz.
自上个世纪以来，生物组织在 1 kHz 以下频率范围内的介电特性的频率相关行为一直存在争议。在这里，我们重新分析了生物组织介电特性的主要资源的原始阻抗表示数据。通过使用 Kramer-Kronig 有效性检验和参数估计技术，我们可以用两个物理参数模型来描述数据，这两个模型对应着两种相反的生物物理解释：一方面，数据只能用组织固有特性来解释，但另一方面，所有被研究的组织都可以找到电极特异性效应的证据。第一种解释将证明继续使用包含四个 Cole-Cole 色散的参数模型是合理的，该模型可以从极低频到极高频率描述介电特性。作为与第二种解释一致的替代方案，我们建议在模型中省略最慢的四个色散之一，并增加静态电导率以解释 1 kHz 以下的频率无关电导率。
