Artikel
Influence of surface modifications of cochlear implant electrodes on impedances and stimulation level
Einfluss von Oberflächenmodifikationen von Cochlea Implantat Elektroden auf Impedanzen und Stimulationslevel
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Veröffentlicht: | 7. September 2006 |
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Gliederung
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Introduction: The electrical impedance of cochlear implant electrodes is one of the factors determining the energy consumption of the implants. It can be influenced by modification of the surface of the electrical contacts.
Methods: In the current study, we investigated the time dependent development of the impedance in different study groups: a) Contour electrode (control), b) Contour electrode plus intraoperative application of steroids, c) Iridium coated Contour electrode and d) Iridium coated electrode plus intraoperative application of steroids. Impedances were measured using standard fitting software. Furthermore, another software was used that allows variation of the pulse width and therefore of the carrier/ stimulation frequency. T- and C-level of the patients were investigated up to two years post fitting.
Results: Intraoperative application of steroids caused a reduction in impedances still to be found after more than two years. Coating of the contacts with Iridium showed no effect even if stimuli with larger pulse width were applied. The stimulation level remained unaffected.
Conclusion: Coating of the contacts with Iridium did not lead to a reduction of the impedances whereas intraoperative application of steroids was efficient. The influence of the impedance on the patients T- and C-level seems to be very low.