Abstract: An insulative housing formed about a distal end of a medical electrical lead body includes a cavity and a port; an ionically conductive medium fills the cavity and is in intimate contact with an electrode surface contained within the cavity. When a current is delivered to the electrode surface contained within the cavity, a first current density generated at the electrode surface is smaller than a second current density generated out from the port of the insulative housing; thus, the port forms a high impedance and low polarization tissue-stimulating electrode.

Abstract: A method of fabricating a stimulation electrode for use on an implantable lead, the lead and electrode so fabricated and a method of their use. The electrode is made by coating a conductive electrode member with a coating of a high surface area coating having micron or sub-micron surface features and after coating, plasma cleaning the electrode member. The electrode is coupled to an insulated conductor of an implantable lead and is employed to stimulate body tissue. The high surface area coating may be platinum black, ruthenium oxide, another metal oxide, a metal nitride or the like. Steroid may be applied to the electrode member after coating.