Different intraoperative electrophyiologic mesurement methods for postion control of cochelar implant electrodes

In daily routine intraoperative measures of impedance and electrically evoked compound action potentials (ECAPs) are used to confirm device integrity and electrode array position. In rare cases the apical part of the electrode can fold over during insertion.

The aim of our study was to identify and characterize the tip fold-over behavior in the spread of excitation (SOE) measurements, additionally using the experimental set up of transimpedance measurements (TIM®) The spread of excitation (SOE) measurements were used to analyze the electrical field distribution of the cochlear implant and were based on the measurement of electrically evoked compound action potentials (ECAPs).

Overall, four cases of a tip fold-over occurred and all cases were detected by spread of excitation (SOE) measurements due to their increasing N1-P1 amplitudes towards the most apical masker electrode 22. With TIM measurement an increased voltage in correlation to the defined electrodes could be determined an shown in curves as well as in a heatmap.

ECAP thresholds didn’t reveal as a reliable indicator for tip fold-over.

Spread of excitation (SOE) measurements are suited to determine a tip fold-over. SOE measurement and so far experimental TIM measurement tool are striking additions to medical imaging after cochlear implantation.

Cochlear Detuschland hat die TIM Software zur Verfügung gestellt.

Publication History

Article published online:
10 June 2020