Toward steerable electrodes: an overview of concepts and current research

Restoration of hearing is a demanding surgical task which requires the insertion of a cochlear implant electrode array into the inner ear while preserving the delicate basilar membrane inside the cochlea for an atraumatic insertion. Already shortly after the first clinical success with early versions of cochlear implants the desire for a controlled insertion of the electrode array arose. Such a steerable electrode should be in its shape adaptable to the individual path of the helical inner ear in order to avoid any contact between the implant and the surrounding tissue. This article provides a short overview of concepts and actuator mechanisms investigated in the past and present with the objective of developing a steerable electrode array for an individualized insertion process. Although none of these concepts has reached clinical implementation, there are promising experimental results indicating that insertion forces can be reduced up to 60% compared to straight and not steerable electrodes. Finally, related research topics are listed which require considerable further improvements until steerable electrodes will reach clinical applicability

Segmentation algorithms for ear image data towards biomechanical studies

In recent years, the segmentation, i.e. the identification, of ear structures in video-otoscopy, computerised tomography (CT) and magnetic resonance (MR) image data, has gained significant importance in the medical imaging area, particularly those in CT and MR imaging. Segmentation is the fundamental step of any automated technique for supporting the medical diagnosis and, in particular, in biomechanics studies, for building realistic geometric models of ear structures. In this paper, a review of the algorithms used in ear segmentation is presented. The review includes an introduction to the usually biomechanical modelling approaches and also to the common imaging modalities. Afterwards, several segmentation algorithms for ear image data are described, and their specificities and difficulties as well as their advantages and disadvantages are identified and analysed using experimental examples. Finally, the conclusions are presented as well as a discussion about possible trends for future research concerning the ear segmentation.info:eu-repo/semantics/publishedVersio

Three-dimensional models of cochlear implants : a review of their development and how they could support management and maintenance of cochlear implant performance

Three-dimensional (3D) computational modelling of the auditory periphery forms an integral part of modern-day research in cochlear implants (CIs). These models consist of a volume conduction description of implanted stimulation electrodes and the current distribution around these, coupled to auditory nerve fibre models. Cochlear neural activation patterns can then be predicted for a given input stimulus. The objective of this article is to present the context of 3D modelling within the field of CIs, the different models and approaches to models that have been developed over the years, as well as the applications and potential applications of these models. The process of development of 3D models is discussed, and the article places specific emphasis on the complementary roles of generic models and user-specific models, as the latter is important for translation of these models into clinical application.http://tandfonline.com/toc/inet202017-05-31hb2016Electrical, Electronic and Computer Engineerin