1. Investigation of cochlear implant impedances over time.
- Author
-
Vormelcher, S., Kley, D., Batsoulis, C., and Büchner, A.
- Subjects
COCHLEAR implants ,BIOELECTRIC impedance ,CONFERENCES & conventions ,IMPEDANCE audiometry ,BIOMARKERS - Abstract
Introduction: Structure and hearing preservation are important factors in cochlear implant (CI) surgery. To improve outcomes, impedance measurements of the CI electrode can be used to monitor these parameters after electrode insertion to detect delayed hearing losses: electrode impedance is thought to be a biomarker for inner ear inflammation after insertion of a CI electrode into the cochlea. Within the present study, impedance changes over time were analyzed using an app-based solution for daily in-vivo impedance measurements of CI recipients. Material and methods: N = 22 participants were asked to use a research software, the Telemetry Study App, to measure the impedance of all 12 electrode contacts morning and evening for a period of at least 4 months after implantation. Depending on the start of electrical stimulation, the cohort was divided into (1) direct activation (DA) and (2) non-DA group. Results: In both groups, lower impedances were observed in the evening compared to the morning with the onset of electrical stimulation. An increase in mean impedances was shown up to 10 days after surgery. Mean impedances of the DA group reached a plateau after about 30 days after surgery while the non-DA group continued to show a slight increase. Impedance values of the DA group remained mostly unaffected from the start of the first fitting week (~day 40 postoperatively) but decreased in the non-DA group. Mean impedances of the non-DA group were slightly lower than those of the DA group at this time but converged at the end of the investigation period. Conclusions: The Telemetry App allowed for daily impedance measurements and hence for monitoring of the inner ear condition. With increased measurement frequency, the impedance development over time after CI surgery could be shown. In addition, daily impedance fluctuations were observed with the onset of electrical stimulation. [ABSTRACT FROM AUTHOR]
- Published
- 2024