A Sleeve-Based, Micromotion Avoiding, Retractable and Tear-Opening (SMART) Insertion Tool for Cochlear Implantation

Objective: In classical cochlear implantation, the insertion of the electrode array is strongly affected by the local anatomy and human kinematics. Herein, we present a concept for an insertion tool that allows to optimize the insertion trajectory beyond anatomical constraints and stabilizes the electrode array in manual implantation. A novel sleeve-based design allows the instrument to be compliant and potentially protective to intracochlear structures, while a tear-open mechanism allows it to be removed after insertion by simply retracting the tool. Methods: Conventional and tool-guided manual insertions were performed by expert cochlear implant surgeons in an analog temporal bone model that allows to simultaneously record intracochlear pressure, insertion forces and electrode array deformation. Results: Comparison between conventional and tool-guided insertions demonstrate a substantial reduction of maximum insertion forces, force variations, transverse intracochlear electrode array movement, and pressure transients. Conclusion: The presented tool can be utilized in manual cochlear implantation and significantly improves key metrics associated with intracochlear trauma. Significance: The instrument may ultimately help improve hearing outcomes in cochlear implantation. The versatile design may be used in both manual cochlear implantation and motorized and robotic insertion, as well as image-guided surgery

Patient-specific estimation of detailed cochlear shape from clinical CT images

PURPOSE A personalized estimation of the cochlear shape can be used to create computational anatomical models to aid cochlear implant (CI) surgery and CI audio processor programming ultimately resulting in improved hearing restoration. The purpose of this work is to develop and test a method for estimation of the detailed patient-specific cochlear shape from CT images. METHODS From a collection of temporal bone [Formula: see text]CT images, we build a cochlear statistical deformation model (SDM), which is a description of how a human cochlea deforms to represent the observed anatomical variability. The model is used for regularization of a non-rigid image registration procedure between a patient CT scan and a [Formula: see text]CT image, allowing us to estimate the detailed patient-specific cochlear shape. RESULTS We test the accuracy and precision of the predicted cochlear shape using both [Formula: see text]CT and CT images. The evaluation is based on classic generic metrics, where we achieve competitive accuracy with the state-of-the-art methods for the task. Additionally, we expand the evaluation with a few anatomically specific scores. CONCLUSIONS The paper presents the process of building and using the SDM of the cochlea. Compared to current best practice, we demonstrate competitive performance and some useful properties of our method

Otological Planning Software - OTOPLAN: A Narrative Literature Review

The cochlear implant (CI) is a widely accepted option in patients with severe to profound hearing loss receiving limited benefit from traditional hearing aids. CI surgery uses a default setting for frequency allocation aiming to reproduce tonotopicity, thus mimicking the normal cochlea. One emerging instrument that may substantially help the surgeon before, during, and after the surgery is a surgical planning software product developed in collaboration by CASCINATION AG (Bern, Switzerland) and MED-EL (Innsbruck Austria). The aim of this narrative review is to present an overview of the main features of this otological planning software, called OTOPLAN®. The literature was searched on the PubMed andWeb of Science databases. The search terms used were “OTOPLAN”, “cochlear planning software” “three-dimensional imaging”, “3D segmentation”, and “cochlear implant” combined into different queries. This strategy yielded 52 publications, and a total of 31 studies were included. The review of the literature revealed that OTOPLAN is a useful tool for otologists and audiologists as it improves preoperative surgical planning both in adults and in children, guides the intraoperative procedure and allows postoperative evaluation of the CI

Individual Optimization of the Insertion of a Preformed Cochlear Implant Electrode Array

Purpose. The aim of this study was to show that individual adjustment of the curling behaviour of a preformed cochlear implant (CI) electrode array to the patient-specific shape of the cochlea can improve the insertion process in terms of reduced risk of insertion trauma. Methods. Geometry and curling behaviour of preformed, commercially available electrode arrays were modelled. Additionally, the anatomy of each small, medium-sized, and large human cochlea was modelled to consider anatomical variations. Finally, using a custom-made simulation tool, three different insertion strategies (conventional Advanced Off-Stylet (AOS) insertion technique, an automated implementation of the AOS technique, and a manually optimized insertion process) were simulated and compared with respect to the risk of insertion-related trauma. The risk of trauma was evaluated using a newly developed “trauma risk” rating scale. Results. Using this simulation-based approach, it was shown that an individually optimized insertion procedure is advantageous compared with the AOS insertion technique. Conclusion. This finding leads to the conclusion that, in general, consideration of the specific curling behaviour of a CI electrode array is beneficial in terms of less traumatic insertion. Therefore, these results highlight an entirely novel aspect of clinical application of preformed perimodiolar electrode arrays in general

Cochlear imaging in the era of cochlear implantation : from silence to sound

Cochlear implants (CIs) are a well accepted treatment for hearing impaired people. In pre- and postoperative assessment of CI-candidates imaging plays an important role to analyze anatomy, rule out pathology and determine intracochlear positioning and integrity of the implant. Developments in CI-design, differences in surgical approach and broadening of treatment indications have raised new questions to radiologists, which were the subject of several studies described in this thesis. For optimal, a-traumatic positioning of a CI precise information about the inner ear anatomy is mandatory. We describe the development, validation and application of a method for 3-dimensional medical image exploration of the inner ear. This renders a tool to obtain cochlear dimensions on clinical computer tomography (CT) images. This will be useful for patientspecific implantplanning. It also shows an anatomical substrate for cochlear trauma during insertion. For postoperative imaging we studied the value of multislice-CT for optimal visualization of the implant within the cochlea. Its role to evaluate operation technique and electrode design, to study frequency mapping and to assess cochlear trauma is discussed. Moreover an international consensus for an objective cochlear framework is presented, forming a common ground for clear and easy exchange of findings in scientific and clinical studies.AB, de Nationale Hoorstichting/Sponsor Bingo Loterij, Foundation Imago, Bontius Stichting inz. Doelfonds BeeldverwerkingUBL - phd migration 201

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

Uncertainty Quantification of Cochlear Implant Insertion from CT Images

International audienceCochlear implants (CI) are used to treat severe hearing loss by surgically inserting an electrode array into the cochlea. Since current electrodes are designed with various insertion depth, ENT surgeons must choose the implant that will maximise the insertion depth without causing any trauma based on preoperative CT images. In this paper, we propose a novel framework for estimating the insertion depth and its uncertainty from segmented CT images based on a new parametric shape model. Our method relies on the posterior probability estimation of the model parameters using stochastic sampling and a careful evaluation of the model complexity compared to CT and µCT images. The results indicate that preoperative CT images can be used by ENT surgeons to safely select patient-specific cochlear implants

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