Objectives
The 32-channel electrode with high-uniformity by an automated process, capability of mass production, and improved mechanical properties was developed. The electrode array needs safety and efficacy evaluation. In this study, Insertion depth of the electrode was evaluated using human temporal bone.
Methods
Eight fresh-frozen human temporal bones were extracted and frozen within 72 hours postmortem. Samples with no medical history or abnormality in the inner ear, middle ear, or external ear were selected and used. Every  insertion was performed by same highly experienced surgeon. The electrodes were inserted through the round window membrane. The electrodes were inserted gently enough without resistance. After the insertion of the electrodes, they were fixed with glue. The cochleae were extracted and microCT images were taken. The number of electrode sites inserted into the cochlea and the insertion depth was measured in the cochlea view.
Results
21 to 32 electrode sites were inserted, with an average of 28.4 ± 3.5. The electrode insertion depth ranges from 270.0 to 486.3°. Their average was 397.7 ± 65.5° which was 1.1 turns of the cochlea.
Conclusion
The developed electrode was inserted into the human temporal bones and their insertion depths were evaluated. On average, 1.1 turns were inserted, which confirmed that the electrode covers basal turn and part of middle turn.

A temporal bone study on insertion depth evaluation of the 32-channel cochlear implant electrode

It is with great pleasure and enthusiasm, that on behalf of the Cochlear Implant centers of the Radboud UMC in Nijmegen and Erasmus MC Sophia Children’s Hospital in Rotterdam to invite you to attend the 16th European Symposium on Pediatric Cochlear Implantation to Rotterdam, the Netherlands in 2023.

Yours sincerely, on behalf of the CI Centers at Radboud UMC and Erasmus MC,