Skip to main content

MEDLab

  2. Publications
  3. Dissertations
  4. Making Cochlear-Implant Electrode Array Insertion Less Invasive, Safer, and More Effective through Design, Magnetic Steering, and Impedance Sensing

Making Cochlear-Implant Electrode Array Insertion Less Invasive, Safer, and More Effective through Design, Magnetic Steering, and Impedance Sensing

AUTHORS

Riojas Katherine E .

ABSTRACT

The focus of this dissertation is on the advancement of the tools and techniques used in cochlear-implant (CI) electrode array (EA) insertion to enable improved insertions that will lead to superior patient hearing outcomes. A CI is a device that helps restore the perception of sound to individuals with profound sensorineural hearing loss. Implantation requires a surgery in which a thin, flexible EA is inserted into an opaque spiral-shaped structure in the head called the cochlea. This insertion requires perception and control near the limits of human perception, leading to the search for better tools and techniques. The first goal of this work was the design, development, and clinical translation of an insertion tool compatible with a minimally invasive CI surgery workspace. There are multiple clinical trials underway of a minimally invasive CI technique in which a single tunnel is drilled to the cochlea entrance; however, the final step of the procedure–insertion of a flexible EA down the narrow tunnel of spiculated bone with restricted visualization and restricted dexterity–remains a significant challenge. The insertion tool developed in this work decreases the challenge posed by this new workspace. The second goal of this work was to decrease insertion trauma through robotic assistance and magnetic steering. Damage to intracochlear structures can lead to irreversible loss of residual hearing and lower hearing outcome potential. This work demonstrated that by steering a magnet-tipped commercial EA on its journey through the cochlea using an external electromagnet, a robotic insertion tool, and image guidance, insertion forces were reduced by approximately 50% compared to robotic assistance alone. The final goal of this work was to increase intraoperative real-time feedback to improve EA placement. Surgeons have limited tactile and visual feedback during insertion to enable successful progress and placement. Traditional localization techniques are not applicable due to accuracy, line of sight, and size restrictions. This work demonstrated that an existing modality traditionally used for post-insertion evaluation, impedance sensing, can be used to inform EA position in real-time and augment the insertion.

Tags: