Analytical solution for contactless electrical impedance measurement

It is possible to measure tissue impedance by inducing eddy currents in the tissue, and measuring the magnetic fields caused by these induced eddy currents. In the presented work, an analytical solution is developed for the induced voltage in the receiver coil(s) in the presence of a small volume inhomogeneity in an otherwise homogeneous tissue. Analytical solutions are compared with numerical FDTD (Finite Difference Time Domain) simulations. The differences in magnetic flux were up to 23% when inhomogeneity was located 10 mm deep, whereas that difference was 6% for the inhomogeneity depth of 30 mm.