Patent ID: 7840273

Claim:
A device for electrically stimulating biological material, in particular retinal material, comprising: an electrode array, configured to be implanted to contact the biological material, said electrode array having a two-dimensional arrangement of individual electrodes (Eij), which upon actuation with a stimulation signal (Vij) produce a stimulation field (S 1 , S 2 , . . .) for the biological material, and an apparatus for actuating the individual electrodes (Eij) with the stimulation signal, said apparatus for actuating the individual electrodes (Eij) being configured to actuate the individual electrodes (Eij) with alternating field stimulation signals (Vij) so that the electrode array forms at least two tripolar or higher multipolar multipole elementary cells (T 1 , T 2 , . . . ; Q 1 , Q 2 , . . .) from three or more adjacent individual electrodes respectively, whereby the stimulation field (S 1 , S 2 , . . .), produced by the multipole elementary cells for the biological material exhibits a rotation component, and at least one of the individual electrodes belongs to at least two multipole elementary cells.