The human cochlea transforms sound waves into electrical signals in the acoustic nerve fibers with high acuity. This transformation occurs via vibrating anisotropic membranes (basilar and tectorial membranes) frequency-specific hair cell receptors. Frequency-positions can be mapped within to create a tonotopic chart which fits an almost-exponential function lowest frequencies positioned apically highest at cochlear base (Bekesy 1960, Greenwood 1961). To date, models of frequency positions...

High-resolution images of the cochlea are used to develop atlases extract anatomical features from low-resolution clinical computed tomography (CT) images. We compare visualization and contrast conventional absorption-based micro-CT synchrotron radiation phase imaging (SR-PCI) whole unstained, nondecalcified human cochleae. Three cadaveric cochleae were imaged using SR-PCI micro-CT. Images visually compared contrast-to-noise ratios (CNRs) n = 27 regions-of-interest (enclosing soft tissue)...

Objective: To three-dimensionally reconstruct Rosenthal’s canal (RC) housing the human spiral ganglion (SG) using synchrotron radiation phase-contrast imaging (SR-PCI). Straight cochlear implant electrode arrays were inserted to better comprehend electro-cochlear interface in implantation (CI). Design: SR-PCI was used cochlea with and without cadaveric CI. Twenty-eight cochleae volume rendered, of which 12 underwent CI a straight via round window (RW). Data input into 3D Slicer software...

<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Objective:</i> Cochlear implants are traditionally programmed to stimulate according a generalized frequency map, where individual anatomic variability is not considered when selecting the centre of stimulation each implant electrode. However, high in cochlear size and spatial distributions exist among individuals. Generalized maps can result large pitch perception errors reduced hearing...

Background: The etiology of Meniere's disease (MD) and endolymphatic hydrops believed to underlie its symptoms remain unknown. One reason may be the exceptional complexity human inner ear, vulnerability, surrounding hard bone. vestibular organ contains an duct system (EDS) bridging different fluid reservoirs. It essential for monitoring hydraulic equilibrium, a dysregulation result in distension spaces or hydrops. Material Methods: We studied EDS using high-resolution synchrotron phase...

The BONEBRIDGE (MED-EL, Innsbruck, Austria) is a bone-conduction implant used in the treatment of conductive and mixed hearing loss. consists an external audio processor floating mass transducer that surgically implanted into skull either transmastoid, retrosigmoid or middle fossa regions. manufacturer includes self-tapping screws to secure transducer; however, self-drilling have also been with success. In cases where not thick enough house transducer, lifts are available variety sizes...

Objective To determine the feasibility of measuring tympanic membrane (TM) vibrations at multiple locations on TM to differentiate normal eardrums from those with associated ossicular pathologies. Design Cadaveric human temporal bone study. Setting Basic science laboratory. Methods A mastoidectomy and facial recess approach was performed four cadaveric bones obtain access ossicles without disrupting TM. Ossicles were palpated ensure mobility an intact chain. Laser Doppler Vibrometry (LDV)...

Abstract A comprehensive experimental study together with statistical analysis was performed to identify the optimal process conditions, materials selection, and curing system for production of thermoplastic vulcanizates (TPVs) based on EPDM rubber polypropylene. Two types systems were studied five different rubber. The TPV products assessed according elastic modulus degree swelling (indicators crosslink density), ultimate tensile strength, elongation, tear compression set. design...

Background: Reports vary on the incidence of vestibular dysfunction and dizziness in patients following cochlear implantation (CI). Disequilibrium may be caused by surgery at base, leading to functional disturbances receptors endolymphatic duct system (EDS) which are located nearby. Here, we analyzed three-dimensional (3D) anatomy this region, aiming optimize surgical approaches limit damage organ. Material Methods: A total 22 fresh-frozen human temporal bones underwent synchrotron radiation...

Summary High‐resolution imaging of middle‐ear geometry is necessary for finite‐element modeling. Although micro‐computed tomography (microCT) widely used because its ability to image bony structures the middle ear, it difficult visualize soft tissues – including tympanic membrane and suspensory ligaments/tendons lack contrast. The objective this research quantitatively evaluate efficacy iodine potassium iodide (IKI) solution as a contrast agent. Six human temporal bones were in experiment,...

Evaluating the accuracy of cochlear duct length (CDL) measurements from a published three-dimensional (3D) analytical model using Synchrotron Radiation Phase-Contrast Imaging (SR-PCI) data will help determine its clinical applicability and allow for adjustments to increase accuracy.Accurate CDL determination can aid in implant sizing full coverage frequency map programming, which has potential improve hearing outcomes patients. To overcome problems with currently available techniques...

Hypothesis: Measuring the length of basilar membrane (BM) in cochlear hook region will result improved accuracy duct (CDL) measurements. Background: Cochlear implant pitch mapping is generally performed a patient independent approach, which has been shown to place-pitch mismatches. In order customize maps, accurate CDL measurements must be obtained. begin at center round window (RW) and ignore basal-most portion BM region. size morphology can improve our understanding tonotopy. Methods: Ten...

The BONEBRIDGE® (Med-El GmbH) is a bone-conduction device comprising an external audio processor and internal Bone Conduction-Floating Mass Transducer (BC-FMT) surgically anchored to the temporal bone. Due implant's size, its placement may be challenging in certain anatomies, necessitating thorough surgical planning. Manual planning methods are laborious, time-intensive, prone errors. This study aimed develop validate automated algorithm for determining skull thickness, aiding of BONEBRIDGE...

The incudostapedial joint (ISJ) of the middle ear is important for proper transmission sound energy to cochlea. Recently, biomechanics ISJ have been investigated using finite-element (FE) modelling, simplified geometry. objective present study was investigate feasibility synchrotron-radiation phase-contrast imaging (SR-PCI) in visualising ultrastructure. Three human cadaveric ISJs were dissected and scanned SR-PCI at 0.9 µm isotropic voxel size. One samples previously 9 images visually...

Abstract The human inner ear contains minute three-dimensional neurosensory structures that are deeply embedded within the skull base, rendering them relatively inaccessible to regenerative therapies for hearing loss. Here we provide a detailed characterisation of functional architecture space hosts cell bodies auditory nerve make safely accessible first time therapeutic intervention. We used synchrotron phase-contrast imaging which offers required microscopic soft-tissue contrast definition...

Background: Incus necrosis is a common complication following stapes surgery and associated with impaired microcirculation. The objective of this study was to investigate the vascular anatomy human incus by using light microscopy, micro-computed tomography (micro-CT), synchrotron phase-contrast imaging (SR-PCI) for novel three-dimensional (3D) analysis middle ear, mucosal folds, major pathways, intraosseous bone channels. Methods: One-hundred-and-fifty temporal bones from Uppsala collection...

Background and Objectives. Hearing loss is one of the most prevalent chronic conditions can significantly impact an individual’s quality life. Cochlear implantation (CI) a widely applicable treatment for severe to profound hearing loss, however CI surgery be difficult surgical trainees master. Training environments that are safe, controlled, affordable needed. To this end, we present virtual-reality (VR) cochlear implant simulator developed with popular, commercial game engine. Method....

Abstract Multi‐input multi‐output (MIMO) models of a twin‐screw co‐rotating extruder for thermoplastic vulcanizate (TPV) are developed using the process identification techniques. The inputs screw speed (SS) and barrel temperature (WT). three outputs motor load (ML), melt (MT), pressure (MP). Two appropriate rubbers TPV applications with different physical mechanical properties used experimentation. model is obtained from experimental input–output data various techniques such as least...

Summary Objectives To demonstrate that synchrotron radiation phase‐contrast imaging (SR‐PCI) can be used to visualize the intrascalar structures in implanted human cochleae and find optimal combination of parameters object‐to‐detector distance (ODD) beam energy (E) for visualization. Materials Methods Three cadaveric temporal bones underwent SR‐PCI with varying combinations ODD (3, 2 1 m) E (47, 60 72 keV). All images were then reconstructed a three‐dimensional (3D) stack slices. The...

The ossicular chain is a middle ear structure consisting of the small incus, malleus and stapes bones, which transmit tympanic membrane vibrations caused by sound to inner ear. Despite being shown be highly variable in shape, there are very few morphological studies ossicles. objective this study was use large sample cadaveric ossicles create set three-dimensional models their statistical variance. Thirty-three temporal bone samples were scanned using micro-computed tomography (μCT)...

Abstract Purpose To introduce and characterize inexpensive easily produced 3D-printed axon-mimetic (3AM) diffusion MRI (dMRI) phantoms in terms of pore geometry kurtosis imaging (DKI) metrics. Methods Phantoms were with a composite printing material that, after dissolution the PVA, exhibits microscopic fibrous pores. Confocal microscopy synchrotron phase contrast micro-CT performed to visualize assess sizes. dMRI scans four identical varying print parameters water at 9.4T. DKI was fit both...