Stimulation and recording of neural tissue, closing the loop on the artifact

To achieve the full potential of neural prostheses, such as those used for the treatment of epilepsy, some means to close the loop around the electrical stimulation protocol has to be provided. To be able to close the loop, it is necessary to record the effect of stimulation itself on the surrounding tissue. Such recording is made impossible by the presence of a long-lasting stimulation artifact, which is due to the presence of residual charge in the electrode. Custom electronics, implementing a novel feedback scheme, can reduce or eliminate such charge and, by making the electronics scalable, a large number of electrodes can be simultaneously accessed. In this work we present such an artifact elimination system.