Apparatus and method for perimodiolar cochlear implant with retro-positioning

摘要

An implantable cochlear electrode array includes an electrode carrier, a groove within the electrode carrier, and a flexible element located in the groove. After the electrode array is implanted, the flexible element may be held in place while the electrode carrier may be partially withdrawn so that the electrode carrier pulls away from the flexible element which emerges from the groove through the surface of the electrode carrier, except where the electrode carrier and the flexible element are attached, so that the electrode carrier wraps around an inner scala tympani wall. A portion of the apical end of the electrode carrier may extend beyond the ends of the groove and the flexible element so that the apical end of the electrode carrier does not wrap around the inner scala tympani wall when the electrode carrier is partially withdrawn after insertion in the cochlea. The electrode carrier may include a perimodiolar section to be positioned next to an inner scala tympani wall of the cochlea, and an outer wall section to be positioned next to an outer scala tympani wall of the cochlea. The perimodiolar section may be shorter than the outer wall section to accommodate the real length difference between the inner and outer walls of the scala tympani of a cochlea. Preferred embodiments are also directed to a method of fabricating a such a cochlear electrode array by negative casting, and to a method of implanting such a cochlear electrode array.