Computationally efficient technique for determining electrode current distribution from a virtual multipole

A system for an electrical neurostimulator coupled to a plurality of electrodes, comprising:

• a processor configured for defining a virtual multipole configuration relative to the plurality of electrodes, determining a distance between each of a group of the electrodes and a virtual pole of the virtual multipole configuration, and determining a stimulation amplitude distribution for the electrode group based on the determined distances, thereby emulating the virtual multipole configuration;
• and
• a controller configured for instructing the electrical neurostimulator to convey electrical energy to the electrode group in accordance with the computed stimulation amplitude distribution.