Impact of the skin conductivity and displacement currents on LF numerical dosimetry

In this paper, the impact of the skin modeling and displacement currents on the induced electric field evaluated by low frequency solvers has been investigated. Both a simplified canonical test-case and a realistic hand-touching electrical stimulation have been selected as meaningful applications without any loss of generality. Similar considerations are indeed expected for other induced contact current dosimetry applications. The modeling of the skin is revealed to play a crucial role and affected also the results in case of neglecting displacement currents. The latter led to maximal errors up to 87 % for the canonical test-case and 16% for the realistic application, while variations up to 86 % in the peak estimated electric fields are obtained inside various tissues when using two different tiers of skin conductivity. A better modeling of the skin from both an electrical and a geometrical point of view is therefore needed. Also, more reliable measurement techniques of tissue dielectric properties are strongly desirable in the low frequency range.