Abstract
BACKGROUND: Cochlear implantation is a surgical procedure in which an electrode array is permanently implanted into the cochlea to stimulate the auditory nerve and allow deaf people to hear. Percutaneous cochlear access, a new minimally invasive implantation approach, requires drilling a single linear channel from the skull surface to the cochlea. The focus of this paper addresses a major challenge with this approach, which is the ability to determine, in a pre-operative CT, a safe and effective drilling trajectory. METHODS: A measure of the safety and effectiveness of a given trajectory relative to sensitive structures is derived using a Monte Carlo approach. The drilling trajectory that maximizes this measure is found using an optimization algorithm. RESULTS: In tests on 13 ears, the technique was shown to find approximately twice as many acceptable trajectories as those found manually by an experienced surgeon. CONCLUSIONS: Using this method, safe trajectories can be automatically determined quickly and consistently.