Cochlear implant including a modiolar return electrode

摘要

A cochlear implant wherein the return path of the electrode array is located to increase current flow through the modiolus. The return electrode is placed at various locations outside the cochlea, and into the modiolus itself. In addition, the electrode array includes an inflatable membrane that is inflated to anchor the array in position in the cochlea with the electrode contacts pressed into contact with the modiolar wall and allowing the membrane to seal with the surrounding tissue of the cochlea, increasing the longitudinal resistance along the cochlear implant electrode, decreasing shunting of the injected current via scala tympani. In experiments that were conducted the current along the modiolus was determined to be, on average, 2.4 times larger with the return electrode in the modiolus than in an extracochlear location.