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ORIGINAL RESEARCH article

Front. Neurol.
Sec. Neuro-Otology
Volume 15 - 2024 | doi: 10.3389/fneur.2024.1417711

Effectiveness of active middle ear implant placement methods in pathological conditions: Basilar membrane vibration simulation

Provisionally accepted
Sinyoung Lee Sinyoung Lee 1*Masaomi Motegi Masaomi Motegi 2Takuji Koike Takuji Koike 3
  • 1 University of Yamanashi, Kofu, Japan
  • 2 Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan
  • 3 The University of Electro-Communications, Chofu, Tōkyō, Japan

The final, formatted version of the article will be published soon.

    Active middle ear implants (AMEI) amplify mechanical vibrations in the middle ear and transmit them to the cochlea. The AMEI includes a floating mass transducer (FMT) that can be placed using two different surgical approaches: "oval window (OW) vibroplasty" and "round window (RW) vibroplasty." The OW and RW are windows located on the cochlea. Normally, sound stimulus is transmitted from the middle ear to cochlea via the OW. RW vibroplasty has been suggested as an alternative method due to the difficulty of applying OW vibroplasty in patients with ossicle dysfunction. Several reports compare the advantages of each approach through pre and postoperative hearing tests. However, quantitatively assessing the treatment effect is challenging due to individual differences in pathologies. This study investigates the vibration transmission efficiency of each surgical approach using a finite-element model of the human cochlea. Vibration of the basilar membrane (BM) of the cochlea is simulated by applying the stimulus through the OW or RW. Pathological conditions, such as impaired stapes mobility, are simulated by increasing the stiffness of the stapedial annular ligament. RW closure due to chronic middle ear diseases is a common clinical occurrence and is simulated by increasing the stiffness of the RW membrane in the model. The results show that the vibration amplitude of the BM is larger when the stimulus is applied to the RW compared to the OW, except for cases of RW membrane ossification. The difference in these amplitudes is particularly significant when stapedial mobility is limited. These results suggest that RW vibroplasty would be advantageous, especially in cases of accompanying stapedial mobility impairment. Additionally, it is suggested that transitioning to OW vibroplasty could still ensure a sufficient level of vibratory transmission efficiency when placing the FMT on the RW membrane is difficult due to anatomical problems in the tympanic cavity or confirmed severe pathological conditions around the RW.

    Keywords: Finite element method, Human cochlear model, Floating mass transducer, Oval window vibroplasty, round window vibroplasty, Mixed hearing loss, Otosclerosis

    Received: 22 May 2024; Accepted: 24 Jul 2024.

    Copyright: © 2024 Lee, Motegi and Koike. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Sinyoung Lee, University of Yamanashi, Kofu, Japan

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.