Redesign of the Hannover Coupler: Optimized Vibration Transfer from Floating Mass Transducer to Round Window

Abstract

Introduction In order to reduce the large variations in clinical outcomes of patients with implanted MED-EL Floating Mass Transducer (FMT) at the round window (RW), several approaches were proposed to optimize FMT-RW coupling. Our previous study showed improved FMT-RW coupling by applying static RW loads utilizing the “Hannover Coupler” (HC) FMT-prosthesis but also demonstrated insufficient low frequency performance. Hence, a redesigned HC version (HCv2) was investigated in this study. Methods Experiments were performed in ASTM F2504-05 compliant fresh human temporal bones. The HCv2 is a FMT-prosthesis redesigned from a previous prototype to specifically improve low frequency performance. Stapes footplate (SFP) displacements in response to acoustic stimulation of the tympanic membrane and to FMT-RW stimulation at varying static force (0–100 mN) were measured by Laser-Doppler vibrometry. Results SFP displacements were highly dependent on the applied RW load and had a global maximum at 15 mN when averaged at speech relevant frequencies (0.5–4 kHz). SFP responses at frequencies ≤ 1 kHz were up to 25 dB higher than responses achieved with the previous HC version. Conclusion Optimizing the HC prosthesis design resulted in improved SFP responses to RW stimulation especially at lower frequencies (≤1 kHz).

The Hannover Coupler V2: Audiological outcomes of a round window coupler for the Vibrant Soundbridge

“…The range of 5 to 20 mN is the suggested range of applied forces for successful RW coupling with the VSB. 24 , 27 …”

“…The correspondence of the upper pin with one of the lower pins indicates forces of 5 mN (first pin) and 20 mN (second pin), respectively. The range of 5 to 20 mN is the suggested range of applied forces forsuccessful RW coupling with the VSB 24,27.…”

Ergebnisse und Lebensqualität nach Implantation aktiver Mittelohrimplantate

“…Typischerweise wird diese durch eine rückwärtige Abstützung mittels Knorpelscheiben erreicht. Um eine Standardisierung der Andruckkraft zu erreichen, fokussiert die Forschung auch auf die Entwicklung eines spezifischen Kuppelelements mit einer mechanischen Feder zur rückwärtigen Abstützung und damit kontrollierbarer Vorlast [158,159]. Der effektive Hörgewinn bei Nutzung eines solchen Koppelelementes liegt zwischen 0,6 und −25 dB [160][161][162], und damit insbesondere im Frequenzbereich > 500 Hz über den mit den bisherigen Couplern erzielten Werten [141,147].…”

“…Typically, it is achieved by backward support with cartilage discs. In order to achieve a standardization of the contact pressure, research focuses on the development of a specific coupling element with a mechanical spring for backward support and thus controllable preload [158,159]. The effective gain of using such a coupling element amounts to 0.6 to − 25 dB [160][161][162] which is higher than the values that could be achieved until now with former couplers, especially in the frequency range of > 500 Hz [141,147].…”