The finite element simulation of dielectric properties of blood

When applying an AC electric field on biological cells, the permittivity and conductivity of cell suspension changes with the frequency of the applied electric field. This phenomenon is commonly known as dielectric relaxation effect. It can be used to predict dielectric properties of cells in blood. It can provide a new medical diagnosis approach to study the electrophysiological characteristics of blood cells and their changes through the experimental measurement of blood´s dielectric parameters under the action of external electromagnetic fields. As a ¿non-invasive diagnosis¿ technology, this detection method has been widely studied. Many have already done a lot of experimental and theoretical researches. We made further simulations of the blood cells suspension under alternating electric field in different frequencies by using the quasi-static electric field module of the finite element analysis software ANSYS. We assume the blood cells suspension to be an ideal three-dimensional model. It is a three-phase two interface structure formed by extracellular liquid, membrane and cytoplasm with different dielectric constants and conductivity. Finally, we obtained the relationship between the frequency of electric field and the real part and imaginary part of dielectric constants of the blood model, or the dielectric spectra of blood respectively. Results indicate that the blood cells suspension model reflects the dielectric properties of the blood at the frequency from 10KHz to 100MHz reasonably, when cell volume fraction is less than 30 percent.