초록 ▼

An implantable electrode array, adapted for insertion into a cochlea, provides a multiplicity of exposed electrode contacts, each having a shape, geometry, or makeup that aids in controlling the current flow and current density associated with the electrode contact as a function of position on the e

An implantable electrode array, adapted for insertion into a cochlea, provides a multiplicity of exposed electrode contacts, each having a shape, geometry, or makeup that aids in controlling the current flow and current density associated with the electrode contact as a function of position on the electrode contact. In one embodiment, the shape or geometry of the exposed electrode contact controls the contact surface of the electrode contact in a way that varies the current flow and current density as a function of surface area position on the electrode, thereby focusing most of the current to flow through the center of the electrode contact. In another embodiment, the electrode contact is coated with a dielectric or other material that controls the surface contact impedance as a function of distance from the center of the electrode, again focusing most of the current flow through the center of the electrode contact. In yet a further embodiment, the exposed electrode contact surface area is masked with an insulator to prevent conduction of current at various locations on the surface of the electrode contact. Separately, or in combination with any of the above embodiments, the exposed electrode contact surface and/or the entire electrode array may be coated with a selected substance or drug compound that diffuses into the tissue and liquids surrounding the electrode. Such substance or drug compound is selected to elicit a desired result, e.g., to inhibit fibrous tissue or bone growth in the vicinity of the electrode contacts; to promote healing of damaged tissue in the region of the electrode contacts, to prevent neural degeneration, or to promote neural regeneration.

대표청구항 ▼

[ What is claimed is:] [1.]1. An implantable electrode array for use with a tissue stimulation device comprisinga flexible carrier;a multiplicity of electrodes having an exposed surface area;a multiplicity of wires embedded within the flexible carrier, at least one wire of the multiplicity of wires

[ What is claimed is:] [1.]1. An implantable electrode array for use with a tissue stimulation device comprisinga flexible carrier;a multiplicity of electrodes having an exposed surface area;a multiplicity of wires embedded within the flexible carrier, at least one wire of the multiplicity of wires being electrically connected to a respective electrode; anda coating that covers at least a portion of the exposed surface area of the multiplicity of electrodes, wherein said coating controls the impedance of the exposed surface area as a function of distance from a center of the exposed surface area.