Design and Thermal Testing of an Automatic Drill Guide for Less Invasive Cochlear Implantation¹

Cochlear implants (CIs) can restore the perception of sound to individuals with severe to profound sensorineural hearing loss. The implanted component of a CI system is an electrode array inserted into the cochlea where it electrically stimulates the intracochlear nerve. Sound is picked up from the environment by an external microphone, filtered, processed, and then converted to electrical signals which are sent to the electrode array. The traditional surgical approach is invasive. A mastoidectomy is performed, in which a fairly large volume of the mastoid region of the temporal bone (approximately 40 mm × 30 mm × 25 mm) is milled away with a high-speed surgical drill to gain access to the cochlea. Vital anatomical structures such as the facial nerve and chorda tympani are embedded within the bone in this region and must be carefully avoided, making the surgery slow and challenging. Due to the invasiveness, risk, and expense...