Although cochlear implants are an established method of restoring hearing, they can have limitations such as increasing current spread and decreasing frequency resolution due to tissue growth around the electrode array. Impedance measurements in cochlear implants have become a versatile tool for intra- and post-operative diagnosis of cochlear implant state. However, most clinical devices use current pulse stimulation already available in the implants and analyze the voltage response in the time-domain and spread along the cochlea. To use the full potential of impedance spectroscopy in differentiating cell types, measurement over an extended frequency range is required. This study presents a simple electrical equivalent circuit for impedance spectroscopy with cochlear implants in a 2-pole configuration. The electrical equivalent circuit describes the electrical properties of the cochlear implant electrode and its electrochemical behavior at the electrode-electrolyte interface by comparing two non-linear bilayer models, Cole-Cole and Schwan-Faraday. The model is validated for four cochlear implant electrodes from four different manufacturers (MED-EL FlexSoft, AB HiFocus SlimJ, Oticon EVO, Cochlear Nucleus CI622) characterized by impedance spectroscopy between 5 Hz and 13 MHz. In the future, this electrical equivalent circuit may help to extract parameters for differentiating cell types around the cochlear implant electrode from an impedance spectroscopic measurement.
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http://dx.doi.org/10.1016/j.heares.2024.109125 | DOI Listing |
Introduction: Neurotrophic factors are widely known for their protective effect on spiral ganglion neurons (SGN) and the protection of these neurons is of great importance to optimize Cochlear Implants, which directly stimulate SGN in deaf patients. Previous studies have identified Cometin - also known as Meteroin-like - to be neuroprotective and beneficial for metabolic disorders. The aim of our study was to investigate the effects of different concentrations of recombinant human Cometin (hCometin) on SGN in regard to neuroprotection and neurite outgrowth and to evaluate its neurite guidance potential using a neurite outgrowth chamber.
View Article and Find Full Text PDFInt J Audiol
January 2025
Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands.
Objective: To assess the impact of cochlear implantation (CI) and speech perception outcomes on the quality of life (QoL) of adult CI users and their communication partners (CP) one-year post-implantation.
Design: This research is part of a prospective multicenter study in The Netherlands, called SMILE (Societal Merit of Intervention for hearing Loss Evaluation).
Study Sample: Eighty adult CI users completed speech perception testing and the Nijmegen Cochear Implant Questionnaire (NCIQ).
Eur Arch Otorhinolaryngol
January 2025
Guilloz Imaging Department, Central Hospital, University Hospital Center of Nancy, Nancy, 54000, France.
Background And Purpose: To evaluate various anatomical parameters and their relationship to chorda tympani nerve (CTN) injury and round window (RW) access during cochlear implantation.
Materials And Methods: Ultra-high-resolution CT images of 66 patients were retrospectively reviewed and compared with operative reports. The facial recess and the round window were analyzed, mainly using the chorda-facial angle (CFA), the width of the facial recess, the CTN-tympanic annulus distance, the RW-mastoid portion of the facial nerve angle, and the type of RW.
Genes (Basel)
January 2025
Department of Hearing Implant Sciences, Shinshu University School of Medicine, Matsumoto 390-8621, Japan.
belongs to the unconventional myosin superfamily, and the myosin IIIa protein localizes on the tip of the stereocilia of vestibular and cochlear hair cells. Deficiencies in have been reported to cause the deformation of hair cells into abnormally long stereocilia with an increase in spacing. is a rare causative gene of autosomal recessive sensorineural hearing loss (DFNB30), with only 13 cases reported to date.
View Article and Find Full Text PDFGenes (Basel)
January 2025
Department of Hearing Implant Sciences, Shinshu University School of Medicine, Matsumoto 390-8621, Japan.
Background/objectives: A heterozygous mutation in the gene is responsible for autosomal dominant non-syndromic hearing loss (DFNA6/14/38) and Wolfram-like syndrome, which is characterized by bilateral sensorineural hearing loss with optic atrophy and/or diabetes mellitus. However, detailed clinical features for the patients with the heterozygous p.A684V variant remain unknown.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!