Motivation for this area of research:
Although measured data for many tissues are available over rather wide frequency ranges (mostly 1kHz-100 GHz), experimental data are scarce for certain frequency bands (e.g. THz frequencies > 100 GHz) or for tissue and cellular substructures. In such cases, the combined knowledge on tissue material composition and microstructure can be used to derive theoretical estimates of tissue electrical properties. Such models (henceforth termed tissue models) are also useful for an understanding of tissue impedance and its variations when subjected to physical and structural changes. The models are physics-based.
1982- eight-layer spherical model for theoretical calculation of field distribution in a single cell and on the membrane by Laplace’s equation and quasi static field solution - frequency :10 MHz-full text (PDF)
1992- spherical dielectric model with low conductivity membrane Assuming low conductivity of the media for the calculation of distribution and absorption rate in single cells by using Laplace’s equation and quasi-static methods – frequency: 10 Hz to 1 GHz- full text (PDF)
1998- calculation of cells connected together through Gap junctions to analyse the influence of the vicinity of cells on membrane potentials, field distribution by numerical ( Finite Element) Method – frequency: from DC to 10 MHz- full text (PDF)
2001- comparison of two layers models of spherical, cylinderical and oval shaped cells in the analysis of the geometry and orientation effects on the induced membrane potentials-field solution by using Finite Element Method - frequency: 900 to 2450 MHz- full text (PDF)
2002- The electrical properties of cervical squamous epithelium have been modelled to Modelled current distribution in tissue and compare modelled and measured impedance spectra and the distribution of current - frequency : 100 Hz to 10 MHz. - full text (PDF)
2003- three-dimensional tissue model with periodic and regular three-dimensional arrangement of spherical cells and non-linear conductivity model for the cell membrane in order to evaluate the distribution of fields in a multicellular tissue model using the Finite Difference Time Domain method- frequency: close to 1 GHz- full text (PDF)
2003- a four layer cell model with irregular and arbitrary shape, in multicellular arrangement to evaluate field distribution in the small region of a tissue using a circuit (transport Lattice) approach- frequency: from DC to 10 GHz-full text (PDF)
2004- single bilayer cell model similar to red blood cell (with cytoplasm and membrane), to study The effect of cell geometry on induced membrane and cytoplasm fields of cells as compared with a spherical model field solution: numerical Finite Element Method- frequency: 2.45 GHz- full text (PDF)
2007- tissue model created by periodic linear arrangement of spherical bilayers. field solution: scaled finite difference method to solve for quasi-static field distributions- frequency: 1800-2450 MHz- full text (PDF)
2010-cell models with irregular shapes to study the effects of cell geometry on the overall electric effective properties shapes are defined by methods such as the superformula and results compared with the results of mixing rules,e.g. Maxwell-Garnet-formula for effective electrical properties- full text (PDF)
2011- For the first time a dielectric multiscale model of biological tissue in the MHz range is established ,fully based on material composition and morphological parameters of the micro- and macro structure, the approach is successfully validated with measurements on human skin- frequency: 5-100MHz- full text (PDF)
2012- cell models with different forms to calculate the dielectric parameters due to irregular cell shape- frequency: DC to 100 MHz- full text (PDF)
2013- theoretical models of cornea and skin to estimate their electrical properties based on constituents, introduced a software package for mixing ruls- frequency:1GHz-1THz- full text (PDF)
2013-a structured model of the dielectric properties of the corneal tissue based on the fine structure and chemical composition of its constituents using mixing rules ,The model is expected to find application in non-invasive medical sensing and for for the prediction of dielectric properties for high-frequency computational dosimetry- frequency: 0.4-10 GHz-full text (PDF)
2014-a new, open-source Matlab toolbox, which can be used to directly build realistic, complex geometrical models of irregular biological cell shapes and organelles based on user definitions on single two-dimensional micrographs,
the software can be used to study the effects of cell shape on local absorption and micro thermal effects under electrical stimulation and in bioelectrical and biomechanical studies-full text (PDF)
2015- multilayered skin model taking into account the electrical properties of the sublayers, numerical dosimetry of magnetic and electric field and computation of the effective electrical properties for the Skin - frequency : 1 Hz – 100 KHz-full text (PDF)