Evaluation of Active Middle Ear Implant using Acoustomechanical Middle Ear Model

The middle ear is a complicated and subtle structure for the sense of hearing, which aims to transmit the sound information to the inner ear. Understanding and reproducing its functions is a critical topic for researchers, because it could lead to the innovation of middle ear implant, but not exclusively. Actually, most of the studies are conducted with human temporal bones, which is not always the best solution, due to the anatomical interindividuality and the post-mortem changes inducing variation in the mechanical properties. Furthermore, there is limited access for such preparation. For these reasons, different groups have invented middle ear models to study the mechanical properties of the middle ear. During this thesis, the model presented in 2000 by Taschke was used. The aim was to parameterize and understand this model, in order to use and study active middle ear implant on it such as the Vibrant Soundbridge (VSB). The model was tested in different conditions and changed with the purpose of obtaining the most reliable transfer function resembling to the ASTM Standards F2504. Having obtained results close to the human temporal bone, the Floating-Mass Transducer (FMT) from VSB was implanted on the model with different couplers. These three different couplers were compared to each other and we simulated different surgical mishandling with the FMT coupling in order to observe their influences on the transfer functions. Even if the model is not as efficient as a temporal bone, it still allows to study an AMEI in a reliable way and to obtain similar results similar results as studies on temporal bones. The acoustomechanical middle ear model could be used as an alternative method to temporal bones.