Effect of stray capacitances on bio-impedances in quasi-static electric field

Evaluating bio-impedances, inevitable stray capacitances have considerable impact on the measurement data. If the stray capacitances are not considered when simulating the electric impedance tomography problem, incorrect conductivities are reconstructed. To study the effect of the stray capacitances, a finite-element model of a test person in surroundings exposed to a quasi-static electric field is used to simulate the measuring setup. Results clearly demonstrate that the displacement currents at high frequencies in air have to be modeled appropriately.