Measuring the electric field of bioelectrodes in saline during stimulation

In order to provide effective vision in a retinal prosthesis, it is necessary to provide sufficient phosphene quantities ideally by parallel stimulation of multiple electrodes. A common, limiting factor in parallel stimulation is the occurrence of cross talk, which can cause undesired tissue stimulation leading to inconsistent percepts. In this paper we present a system developed for measuring the electric field in an in vitro environment by stimulation of bioelectrodes immersed in an electrolyte. The results from this study provides a better understanding of the electric field generated by stimulating electrodes. Calculation of activation area can provide useful information in regards to electrode separation to eliminate cross talk during parallel stimulation.