Electrode system for ossified cochlea

An electrode system for use within an ossified cochlea comprising:

• a first flexible electrode array having a multiplicity of electrode contacts, wherein each of the electrode contacts of the first electrode array is electrically connected to a respective output channel of an implantable cochlear stimulator (ICS);
• a second flexible electrode array having a multiplicity of electrode contacts, wherein each of the electrode contacts of the second electrode array is electrically connected to a respective output channel of the ICS which is not connected to the electrode contacts of the first electrode array;
• and
• an electrode positioner for insertion into the cochlea alongside one of the first or second flexible electrode arrays;
• wherein the first flexible electrode array has a first side, and wherein the multiplicity of electrode contacts are all positioned on said first side.

A method of stimulating spiral ganglion cells within an ossified cochlea comprising:

• drilling a first tunnel into an ossified portion of the cochlea up to a first bend in the scala tympani or scala vestibuli of the cochlea;
• inserting a first electrode array into the first tunnel, the first electrode array having a plurality of spaced-apart electrode contacts along one side thereof;
• electrically connecting the electrode contacts of the first electrode array to a cochlear stimulator;
• inserting a second electrode array into the cochlea near the location where the second turn of the cochlea begins, the second electrode array having a plurality of spaced-apart electrode contacts along only one side thereof inserting an electrode positioner into the cochlea alongside one of the first or second flexible electrode arrays;
• electrically connecting the electrode contacts of the second electrode array to the cochlear stimulator;
• and
• controlling the cochlear stimulator so as to apply a pattern of stimulation pulses to the electrode contacts of the first and second electrode arrays.