Biosensor functionality for cochlear implants

Cochlear implants (CI) are considered the most successful sensory prosthesis, providing a solution for severe to complete deafness. Despite widespread clinical success of CI, little is known on how to avoid cochlear damage and inflammation during surgical insertion. This is crucial to preserve residual hearing and facilitate re-implantation, which is expected 2-3 times for a congenitally deaf child during lifespan. In this project we will investigate the added value of in situ monitoring of electrode-tissue interface through intracochlear imaging and biosensing functionalities. Usually, the cochlea is regarded a black box. By applying optical coherence tomography, based on a low coherence interferometry, we will visualize and guide the insertion inside the cochlea. We will also develop electrochemical biosensors on standard CI electrodes to detect inflammation markers. Furthermore, we aim to investigate how cochlear inflammatory processes relate with measurable changes in the electrical properties of the electrode-cochlea interface. For this, we will use dielectric spectroscopy, a technique that reveals molecular relaxations and electrical properties. Experiments will be performed in vitro (artificial perilymph and cadaver temporal bones) and in vivo in the Guinea pig CI model. Fundamental insights from the exciting interplay between soft matter physics, biosensors and hearing prosthesis will lead to a breakthrough in the understanding of acute inflammation during CI surgery.