Fig. 2

The top, middle, and bottom images are plots of the electric potential, current density, and magnetic flux density, respectively, in the plane \(z=0\). The dashed white line indicates the circumference of the sphere. In the cartesian coordinates on this graph the current point source is at \((5,0)\) and the current point sink is at \((0,-5)\). The ratio \(\rho_{e}/\rho_{o}=1\). In the top graph we show extracellular potential of the sphere of tissue amid the external potential in the conducting bath. There the black lines are equipotentials and the shade of color corresponds to the magnitude. In the middle graph we show the external current density in the bath and the sum of the intracellular and extracellular current densities in the sphere. The magnetic flux density shown in the bottom graph was calculated from the current density field