Fig. 6

a Geometry and boundary conditions of the theoretical model used to estimate the values of electrical conductivity associated with the doped zone in the agar phantoms. Dimensions: r₀ = 50 mm, z₀ = 110 mm, r_i = 0.75 mm, z₁ = 40 mm, z₂ = 70 mm. V_i = 2 V. b 2D axisymmetric model used to study the temperature distributions during RF ablation of a doped zone with different dopants. It consisted of a cylinder of non-doped liver tissue (radius r_o = 10 cm and height z₀ = 16 cm) surrounding a spherical doped zone of variable radius (dashed red line, r_t = 2, 3 and 4 cm). The active electrode (r_e = 0.75 mm) is inserted into the center of the doped zone. Solid blue line represents the contour of the coagulation zone, and A and B are the axial and transverse diameters, respectively