Neurostimulators are used to stimulate human tissue in many applications, including retinal prostheses and neurological disease treatments. Neurostimulators often use more than one electrode to improve the stimulation resolution and efficacy of the array. Regular electrodes, however, present zones of large current density such that increasing the number of electrodes in one array causes tissue damage.
Virtual electrodes enhance stimulation resolution without causing tissue damage by creating large current density zones away from the electrodes. A virtual electrode is placed between two regular electrodes to enhance the signal quality and increase targeting capabilities. By routing the current from each regular electrode, the array can stimulate tissue not directly under the electrodes. This increases stimulation resolution without overstimulating one specific area.