Electric current distribution in tissues upon electrotherapy.

The authors have used computer simulations to study electric current distribution in tissues upon electrotherapy. The results are shown on a computer plot and apply to various types of current. Simulations on a simplified circular structure (as a model of a limb cross section) give a better understanding of the problem and clearly demonstrate the influence of electrode position and geometry. Simulations have established the possibility of directing the current density at particular internal areas. The greatest current density occurs close to the surface of the bone in an area midway between the electrodes, and larger electrodes may make treatment more effective. These conclusions are verified in the more realistic structure of a thigh cross section and extrapolation to a length section is made. Finally, the influence of metallic implants is considered. The conclusions of this work are of great practical interest to electrotherapy, particularly electrode techniques.