Author Spotlight: Advancements in Impedance Monitoring for Cochlear Implant Surgery

We are working with impedances, since they provide an objective feedback on whether the cochlear implant electrode array is located outside the cochlea or inside the cochlea. High impedances indicate or suggest a poor conductivity, and thus, an electrode contact outside the cochlea. Whereas lower impedances suggest that the conductivity is better, and thus, the electrode contact already inserted.

And this information may be used to reduce radiation exposure in the aftercare of cochlear implantation after care. Hearing preservation is an increasing topic of interest in the cochlear implantation field. And with these methods that objectify the position of the electrode array inside the cochlea, and with this, the potentially occurring intracochlear damage are increasingly becoming very important.

The current methods for the intraoperative monitoring of the electrode array insertion and the hearing preservation are the electrocochleography and the hear present impedance telemetry. The major tasks to overcome are unexpected high impedances. These high impedances resolve with time and electrical stimulation.

Nevertheless, they negatively influence the real-time measurements. We established a method to perform repeated and continuous impedance telemetry measurements, and they open up a whole new perspective on gaining data already during the insertion of a cochlear implant electrode array.