The electric properties of biological tissues can be described by a

The electric properties of biological tissues can be described by a complex tensor comprising a simple expression of the effective admittivity. a cube-shaped object with several different biologically relevant compositions. These precise definitions of effective admittivity may suggest the ways of measuring it from boundary current and voltage data. As in the homogenization theory, the effective admittivity can be computed from pointwise admittivity by solving Maxwell equations. We compute the effective admittivity of simple models as a function of frequency to obtain Maxwell-Wagner interface effects and Debye relaxation starting from mathematical formulations. Finally, layer potentials are used to obtain the Maxwell-Wagner-Fricke expression for any dilute suspension of ellipses and membrane-covered spheres. 1. Introduction The human body can be regarded as a complex electrical conductor comprising many tissues that have unique electrical properties. Measurements of the electrical properties of biological tissues have shown that effective conductivity (is determined by its ion concentrations in extra- and intracellular fluids, cellular structure and density, molecular compositions, membrane characteristics, and other factors. Cell membranes contribute to capacitance; the intracellular fluid gives rise in an intracellular level of resistance; the extracellular liquid plays a part in effective level of resistance. As a total result, natural tissue show a adjustable response within the regularity range from several Hz to MHz. For some natural tissue, = + is certainly regular [6]. The effective admittivity as well as the voxel 100?MHz of biological tissues as a way of characterizing tissues structural information associated with biological cell suspensions [7, 8]. In 1873, Maxwell [9] produced a manifestation of = 0) for the particular case of BI6727 enzyme inhibitor the strongly dilute suspension system of spherical contaminants and = 0. Wagner expanded the appearance to an over-all be considered a three-dimensional area using a pointwise admittivity of may very well be a union of several voxels in a way that within the voxel will need to have a finite energy [20]: ( = r : 0 1?cm using its 3 pairs of facing areas (Body 2): is distributed by and by and planes, (b) current shot through and planes, and (c) current shot through and planes. Open up in another window BI6727 enzyme inhibitor Body 2 A tissues sample within the device cube. Lemma 1 (reciprocity) For and divergence theorem, we’ve because of the pursuing theorem. Theorem 2 If may be the option of (6), you have = 1 after that, as well as the divergence theorem, we n possess = 0 and ?= 1, and each end up being the difference provided in (7). The effective admittivity tensor 106 After that, ? depending only in the + 1. Because of this sample, the is known as a rest period, since its worth controls polarization period [8, 21]. It really is remarkable to see that this relaxation time = ((1 BI6727 enzyme inhibitor ? generated inside the dielectric due to the common electric field E = ?0 1?is given by = is produced by the ionic conduction and = 1/2= (1/2 10?kHz): The 10?MHz): In biological tissues, the 10?MHz, the dielectric behavior of the tissues is dominated by the heterogeneous composition and ionic activities inside the biological tissues. These effects are in charge of the 10 principally?GHz). The relative line. Open up in another window Amount 6 Dielectric dispersion curves: (a) Cole-Cole story, (b) series. Remark 4 In the case when is definitely sufficiently small (dilute suspension) so that |1 ? ? 1, (21) can be indicated as = r : ?1 1??be a cube, and let = r : (Number 7) be given by and a single layer potential: is determined by = |= = (is sphere) and the volume fraction = |= (of a thickness changes abruptly across the membrane within a dilute sole suspension of a thin membrane of thickness in 1D. 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