Current management system for a stimulation output stage of an implantable neurostimulation system

Abstract

A current management system for use in the stimulation output stage of a neurostimulation system can be programmed to steer different amounts of current through different stimulation electrodes to vary how strongly the tissue adjacent each electrode is stimulated during a particular programmed stimulation episode. An stimulation electrode drive circuit associated with each electrode that is available for stimulation allows independent control of the flow of current through that electrode. A reference electrode is provided in the circuit to source or sink current as necessary to balance the currents going into and out of the patient, so that no stimulation electrode is required to serve that purpose. More specifically, by configuring the circuit to maintain a constant potential at the reference electrode (e.g., a potential that is approximately half way between a top and bottom voltage rail), the reference electrode will source or sink currents as necessary to cause the net current flow into the patient to be equal to the net current flowing out of the patient, thus satisfying Kirchhoff's current law.

Dependencies are inferred from the claim text.