Ear Model Research Articles

A Virtual Inner Ear Model Selects Ramped Pulse Shapes for Vestibular Afferent Stimulation.

Bilateral vestibular deficiency (BVD) results in chronic dizziness, blurry vision when moving the head, and postural instability. Vestibular prostheses (VPs) show promise as a treatment, but the VP-restored vestibulo-ocular reflex (VOR) gain in human trials falls short of expectations. We hypothesize that the slope of the rising ramp in stimulation pulses plays an important role in the recruitment of vestibular afferent units. To test this hypothesis, we utilized customized programming to generate ramped pulses with different slopes, testing their efficacy in inducing electrically evoked compound action potentials (eCAPs) and current spread via bench tests and simulations in a virtual inner model created in this study. The results confirmed that the slope of the ramping pulses influenced the recruitment of vestibular afferent units. Subsequently, an optimized stimulation pulse train was identified using model simulations, exhibiting improved modulation of vestibular afferent activity. This optimized slope not only reduced the excitation spread within the semicircular canals (SCCs) but also expanded the neural dynamic range. While the model simulations exhibited promising results, in vitro and in vivo experiments are warranted to validate the findings of this study in future investigations.

Photoacoustic imaging of the dynamics of a dye-labeled IgG4 monoclonal antibody in subcutaneous tissue reveals a transient decrease in murine blood oxygenation under anesthesia.

Over 100 monoclonal antibodies have been approved by the U.S. Food and Drug Administration (FDA) for clinical use; however, a paucity of knowledge exists regarding the injection site behavior of these formulated therapeutics, particularly the effect of antibody, formulation, and tissue at the injection site. A deeper understanding of antibody behavior at the injection site, especially on blood oxygenation through imaging, will help design improved versions of the therapeutics for a wide range of diseases. The aim of this research is to understand the dynamics of monoclonal antibodies at the injection site as well as how the antibody itself affects the functional characteristics of the injection site [e.g., blood oxygen saturation ()]. We employed triple-wavelength equipped functional photoacoustic imaging to study the dynamics of dye-labeled and unlabeled monoclonal antibodies at the site of injection in a mouse ear. We injected a near-infrared dye-labeled (and unlabeled) human IgG4 isotype control antibody into the subcutaneous space in mouse ears to analyze the injection site dynamics and quantify molecular movement, as well as its effect on local hemodynamics. We performed pharmacokinetic studies of the antibody in different regions of the mouse body to show that dye labeling does not alter the pharmacokinetic characteristics of the antibody and that mouse ear is a viable model for these initial studies. We explored the movement of the antibody in the interstitial space to show that the bolus area grows by over 24h. We discovered that injection of the antibody transiently reduces the local levels in mice after prolonged anesthesia without affecting the total hemoglobin content and oxygen extraction fraction. This finding on local oxygen saturation opens a new avenue of study on the functional effects of monoclonal antibody injections. We also show the suitability of the mouse ear model to study antibody dynamics through high-resolution imaging techniques. We quantified the movement of antibodies at the injection site caused by the interstitial fluid, which could be helpful for designing antibodies with tailored absorption speeds in the future.

Influence of Dose, Particle Size and Concentration on Dermal Penetration Efficacy of Curcumin.

The influence of size, particle concentration and applied dose (finite vs. infinite dose) on the dermal penetration efficacy of curcumin was investigated in this study. For this, curcumin suspensions with different particle sizes (approx. 20 µm and approx. 250 nm) were produced in different concentrations (0.625-5% (w/w)). The dermal penetration efficacy was determined semi-quantitatively on the ex vivo porcine ear model. The results demonstrated that the presence of particles increases the dermal penetration efficacy of the active compounds being dissolved in the water phase of the formulation. The reason for this is the formation of an aqueous meniscus that develops between particles and skin due to the partial evaporation of water from the vehicle after topical application. The aqueous meniscus contains dissolved active ingredients, and therefore creates a small local spot with a locally high concentration gradient that leads to improved dermal penetration. The increase in penetration efficacy depends on the number of particles in the vehicle, i.e., higher numbers of particles and longer contact times lead to higher penetration efficacy. Therefore, nanocrystals with a high particle concentration were found to be the most suitable formulation principle for efficient and deep dermal penetration of poorly water-soluble active ingredients.

Use of simulated data to explore the application of optical coherence tomography for classifying middle-ear pathologies.

Optical coherence tomography (OCT) vibrometry is a non-invasive tool for functional imaging of the middle ear. It provides spatially resolved vibrational responses and also anatomical images of the same ear. Our objective here was to explore the potential of OCT vibration measurements at the incus, as well as at the umbo, to distinguish among middle-ear disorders. Our approach was to build finite-element models of normal and pathological ears, generate large amounts of synthetic data, and then classify the simulated data into normal and pathological groups using a decision tree based on features extracted from simulated vibration magnitudes. We could distinguish between normal ears and ears with incudomallear joint (IMJ) disarticulation or stapes fixation, with the sensitivity and specificity both being 1.0; distinguish between stapes fixation and IMJ disarticulation with a sensitivity of 0.900 and a specificity of 0.889; and distinguish ears with ISJ disarticulation from normal ears with a sensitivity of 0.784 and a specificity of 0.872. Less extreme pathologies were also simulated. The results suggest that the vibration measurements within the middle ear that can be provided by OCT (e.g., at the incus) may be very valuable for diagnosis.

Finite element analysis of repairing tympanic membrane perforation using autologous graft material and biodegradable bionic cobweb scaffold

Background and objectiveAs for repairing the perforated tympanic membranes (TM), temporalis fascia and tragal cartilage are popular in clinics as autologous graft materials. However, there is a significant hearing loss after repairing the TM with autologous graft materials, which needs to be addressed in biomechanical engineering. MethodsThe finite element model of normal middle ear is improved from two aspects: the repair method of tympanic fibrous layer and the bionic spider web tympanic scaffold. By creating the solid-shell coupling condition and strong coupling boundary condition to simulate the repair, TM umbo and stapes footplate displacement-frequency response are explored in 200–8000 Hz. ResultsThe tympanic membrane perforation (TMP) causes a significant conductive hearing loss in high frequency region, which is positively correlated with perforation area. Both temporalis fascia and tragal cartilage still perform a certain degree of high-frequency hearing loss after repairing TMP. The TM attachment the magnesium alloy scaffold (MAS) prevents appropriately the high frequency hearing loss after autologous graft repair and makes the sound transmission closer to the normal condition. Significantly, the density of graft material has a negative effect on high-frequency sound transmission without the MAS. The modal-motion of TM repaired with temporalis fascia and tragal cartilage is improved significantly after attaching the MAS. In addition, the MAS restores effectively the configuration and vibration frequency of the repaired TM, which is similar to that of the native TM. ConclusionThe area size of TMP is studied through the finite element method, which includes autologous graft materials, the MAS, parameter sensitivity analysis, modal analysis of graft material and the MAS in biological form on the effect of middle ear sound transmission. Relevant conclusions provide some references for clinical trial protocol and the follow-up repair ideas of TM of tympanoplasty.

Hydroxy-α-sanshool has anti-inflammatory and antioxidant effects and affects the NF-κB/STAT3 pathway via TRPV1 in acne

Hydroxy- α-sanshool (HAS), an extract derived from Zanthoxylum plants, possesses anti-inflammatory and antioxidant effects. However, its potential effects on acne have not been reported. In this study, 2% absolute ethanol formulation of HAS was effective in inflammatory rashes in a rabbit ear model of acne, surpassing the performance of 0.1% adapalene and matching the effectiveness of 10% benzoyl peroxide, but with a faster onset of action. HAS effectively inhibited Cutibacterium acnes (C. acnes) growth with a minimum inhibitory concentration of 1.25 mg/mL. HAS could effectively inhibit the expression of reactive oxygen species (ROS), various inflammatory factors, and the activation of NF-κB and STAT3 pathways induced by C. acnes in HaCat and THP-1 cells. HAS's antioxidant and anti-inflammatory effects in acne may be mediated through TRPV1. Notably, 2% HAS lotion alone display efficacy in reducing inflammatory rashes in patients with mild to moderate acne, but studies with large samples are needed.

Simulation and Experimental Validation of Alternate Pathways of Impulse Noise Conduction Into the Inner Ear

Abstract Recent data from heavy weapons training and breaching exercise environments suggest that protection of the ear canal alone may not be sufficient to prevent detrimental effects of blast-induced impulse noise on the Warfighter. This work is to elucidate alternate pathways of impulse noise penetration into the inner ear, including through the soft tissues of the head and bone conduction, gain insight into the fundamental mechanism(s) of blast induced hearing loss and validate the computational model with experiment. We have exposed the instrumented head model to impulse noise events generated via a shock tube (sound pressure level > 140 dB) to identify the role of bone conduction in pressure build up in the inner ear. Concurrently, we have developed a finite element (FE) model of the head to simulate the biomechanical response of the ear to impulse noise. The loading condition applied to the model to characterize the biomechanical effects in the ear is derived from notional weapons firing incidents. We have also developed an inner ear model to analyze the dynamic behavior of the basilar membrane when subjected to skull vibration stimulated by an impulse noise event. Using the simulated motion of the basilar membrane, we attempted to establish the relationship between the impulse noise and possible auditory disruption outcomes to the inner ear.

Intralesional Axitinib Injection Mitigates Hypertrophic Scar by Inhibiting Angiogenesis Pathway: A Preliminary Study in a Rabbit Ear Model.

High levels of VEGF and excessive angiogenesis contribute significantly to hypertrophic scar (HS) formation. Our study aimed to preliminarily investigate the effect of axitinib, a selective VEGF receptor tyrosine kinase inhibitor, on angiogenesis of HS and to explore its possible mechanism in a rabbit ear model. Ten male New Zealand white rabbits were used to establish HS models and then randomised to the control and axitinib groups. The scar tissues in the two groups were injected with axitinib or normal saline, and they were evaluated after one month of treatment. Macroscopic scar thickness, vascularity and pliability, as well as histopathological analysis including HE staining and Masson staining and scar elevation index (SEI) between two groups were compared. Immunohistochemical staining of CD31 in two groups was conducted to assess the degree of angiogenesis in HS tissue. The protein expression of protein kinase B (AKT) and ribosomal protein S6 kinase (p70S6K) and their phosphorylation levels in both groups were examined by Western blot analysis. The macroscopic and histological observation showed intralesional axitinib injection significantly reduced scar thickness, vascularity and pliability of HS in the rabbit ear model. The value of SEI in HE assessment was also significantly declined in the axitinib group. Furthermore, immunohistochemical analysis revealed that axitinib suppressed the expression of CD31 in HS tissue, and the mean IOD for blood vessels was significantly lower in the axitinib-treated group. Additionally, axitinib effectively attenuated the protein expression of p70S6K, p-AKT and p-p70S6K by Western blot analysis. Our study suggests that intralesional injection of axitinib can effectively attenuate HS by reducing angiogenesis in the rabbit ear model, and this inhibitory effect may be mediated by suppression of AKT/p70S6K signaling pathway. It indicates that axitinib may be a promising option for the treatment of HS in the future.

Exploring the Potential of Hesperidin in Preventing Hypertrophic Scars: Insights from a Rabbit Ear Model.

Hypertrophic scars, commonly occurring after trauma or surgery in critical areas like the head and joints, pose significant challenges to both physical and mental health due to their impact on skin function and aesthetics. While the complex pathogenesis involves fibroblast activation and collagen deposition, effective treatments are lacking, underscoring the importance of exploring pathogenesis and targeted therapies. Hesperidin, a bioactive compound in citrus fruits with diverse health benefits, including anti-fibrotic and anti-angiogenic effects, is the focus of this study with the aim of investigating its impact on hypertrophic scar formation, given its potential to promote blood flow and improve skin microcirculation. This study aimed to observe the inhibitory effect of topical hesperidin on hypertrophic scars in rabbits. A total of 8 healthy adult New Zealand white rabbits were used to establish a rabbit hypertrophic scarring animal model. Five wounds were created on each rabbit's two ears, with three wounds on the left ear (groups A, B, and C) and two wounds on the right ear (groups D and E). After six days of wound drying postoperatively, the wounds were locally treated with medication as followed: group A, 0.1% hesperidin; group B, 1% hesperidin; group C, 1% triamcinolone acetonide; group D, Vaseline; and group E, blank control without any medication. After 28 days, the scar tissue samples were collected for histological examination. The results showed that the scar texture of groups B and C was softer and lighter in color, and the number of fibroblasts, capillaries, and inflammatory cells in the tissue was significantly less than those in the other three groups. The hypertrophic scar indices of groups B and C were significantly smaller than those of groups A, D, and E, and the difference was statistically significant (P < 0.05). There were no significant difference between groups B and C. Topical application of hesperidin demonstrated promising potential for reducing hypertrophic scar formation in rabbits.

Effect of triangular mesh resolution on the geometrical trueness of segmented CBCT maxillofacial data into STL format

ObjectivesTo determine the optimal level of mesh reduction that would maintain acceptable levels of geometrical trueness while also minimizing the impact on other parameters such as file size and processing time. MethodsIntraoral and extraoral maxillofacial defects were created on 8 cadaver heads and scanned by using a CBCT scanner (NewTom 3D Imaging, Verona). DICOM data were segmented to produce head (n=8) and skull models (n=8) saved as standard tessellation language (STL) files. A further processing of head models was preformed to produce face (n=8) and ear models (n=8). A mesh reduction process was performed for each STL model (reference, R0) by generating 50% (R1), 75% (R2), and 90% (R3) reductions. The 3 datasets were compared to the R0 file using 3D evaluation software (GOM Inspect) using a global best-fit algorithm, to calculate the root mean square (RMS) deviations. Statistical analyses were performed at a level of significance of α=0.05. ResultsThere was no 3D deviation after the 50% triangular mesh reduction in the 4 datasets. Minor 3D deviations were observed after 75% reduction, in all groups. After 90% reduction, higher 3D deviations were observed, and especially in head and skull. Statistically significant increase in 3D deviations was observed with higher degrees of mesh reduction (p < 0.001). ConclusionThe resolution of CBCT-based maxillofacial defect models can be reduced up to 50%, with neglectable concern to inaccuracy. Clinical SignificanceAccurate maxillofacial models can be obtained from CBCT DICOM files after segmentation and export as STL files, even when the mesh resolution is reduced up to 50%. This information can be valuable for practitioners and researchers working with 3D models of maxillofacial defects.

Melatonin inhibits fibroblast cell functions and hypertrophic scar formation by enhancing autophagy through the MT2 receptor-inhibited PI3K/Akt /mTOR signaling

Hypertrophic scar (HS) is a fibrotic skin condition and characterized by abnormal proliferation of myofibroblasts and accumulation of extracellular matrix. Melatonin, an endogenous hormone, can alleviate fibrosis in multiple models of diseases. This study examined the effect of melatonin on fibrosis in primary fibroblasts from human HS (HSFs) and a rabbit ear model and potential mechanisms. Melatonin treatment significantly decreased the migration and contraction capacity, collagen and α-smooth muscle actin (α-SMA) production in HSFs. RNA-sequencing and bioinformatic analyses indicated that melatonin modulated the expression of genes involved in autophagy and oxidative stress. Mechanistically, melatonin treatment attenuated the AKT/mTOR activation through affecting the binding of MT2 receptor with PI3K to enhance autophagy, decreasing fibrogenic factor production in HSFs. Moreover, melatonin treatment inhibited HS formation in rabbit ears by enhancing autophagy. The anti-fibrotic effects of melatonin were abrogated by treatment with an autophagy inhibitor (3-methyladenine, 3-MA), an Akt activator (SC79), or an MT2 selective antagonist (4-phenyl-2propionamidotetralin, 4-P-PDOT). Therefore, melatonin may be a potential drug for prevention and treatment of HS.

Comparison research on the therapeutic effects of botulinum toxin type A and stromal vascular fraction gel on hypertrophic scars in the rabbit ear model

Background and objectivesBotulinum toxin type A (BTA) is often used for wrinkles and muscle convulsive diseases due to its blocking of the transmission of nerve impulses. Stromal vascular fraction gel (SVF-gel) prepared from adipose tissue has novel effects on skin depression and poor texture. Both BTA and SVF-gel are proved to possess anti-scar potential. This study aimed to assess and compare their therapeutic effects on hypertrophic scars. Materials and methodsThe rabbit ear scar model was established and treated with BTA and SVF-gel, alone or in combination. Gross evaluation using Manchester Scar Scale (MSS) was conducted immediately, 4 and 8 weeks after initial treatment. After tissue sample harvest, histological and Western blot analyses were performed. ResultsAll the treatments alleviated scar hyperplasia in different degrees by inhibiting fibroblast activation (Ki-67, α-SMA), tissue inflammation (CD45, IL-1β) and the transforming growth factor-β1 (TGF-β1)/Smad3 pathway. Despite an excellent anti-inflammatory effect, improvement of scar appearance and pathological characteristics in SVF-gel-contained groups was not as good as that in BTA-only group, which might be related to the retention of M2-type macrophages (CD163 +) and partial maintenance of TGF-β1 expression. ConclusionOur data suggest that BTA has better anti-scar efficacy than SVF-gel, and the combination of these two treatments shows no obvious combinatorial effect.

Layered GelMA/PEGDA Hydrogel Microneedle Patch as an Intradermal Delivery System for Hypertrophic Scar Treatment.

Hypertrophic scar (HS) is an unfavorable skin disorder that typically develops after trauma, burn injury, or surgical procedures and causes numerous physical and psychological issues in patients. Currently, intralesional multi-injection of corticosteroid, particularly compound betamethasone (CB), is one of the most prevalent treatments for HS. However, injection administration could result in severe pain and dose-related side effects. Additionally, the vacuum therapeutic efficacy of this treatment relies on the level of expertise of the healthcare professional. To overcome the limitations of conventional injections, a new method that is convenient, painless, and self-administrable is urgently required. In this study, we developed a methacrylate gelatin (GelMA)/polyethylene glycol diacrylate (PEGDA) double-network hydrogel microneedle patch loaded with CB (CB-HMNP) as an intradermal delivery system for HS treatment. The double-network structure conferred the CB-HMNP with sufficient mechanical properties to successfully penetrate scar tissue while also helping to regulate the drug's sustained release rate. Subsequently, we confirmed that the CB-HMNP had a pronounced inhibitory effect on human HS fibroblasts (hHSFs), whereas drug-free HMNPs had no effect on hHSFs, indicating its high biocompatibility. In order to assess the therapeutic efficacy of CB-HMNPs, HS models of New Zealand rabbit ears were developed. The administration of CB-HMNP three times significantly decreased the scar elevation index (SEI), collagen I/III, and transforming growth factor-β1 (TGF-β1) protein. Therefore, the CB-HMNP may offer an administration pathway for the treatment of HS that is less painful, more convenient, less invasive, and sustain-released.

Frequency Selectivity via Inner Boundary Conditions for A Self‐Powered Multiresonant Acoustic Sensing Array with Broad Bandwidth

AbstractThis study investigates and proposes innovative approaches to achieve frequency selectivity within a limited space. Traditional multiresonant acoustic devices use individual sensing elements of varying sizes to achieve resonance frequency (fr), leading to an inability to sense focused acoustic waves, unlike the human ear. A miniaturized, self‐powered artificial basilar membrane that incorporates multiresonant features is introduced. Multiple fr of the diaphragms are developed using inner boundary conditions (iBCs) defined by an adjustable micropatterned elastomeric support (µ‐support) and a porous nanofiber (NF) mat. This new approach offers the advantage of all‐in‐one fabrication, eliminating the need for device area variation or an additional rigid frame typically required in conventional multiresonant acoustic devices. The efficacy of the iBCs in shifting fr within the vocal frequency ranges is verified via a laser Doppler vibrometer, simulation, and triboelectric output. With its self‐powering capabilities based on triboelectric principles, this artificial basilar membrane holds promise for accurately recognizing musical and vocal signals with specific frequency characteristics. With four different iBCs in a total device area of 23 × 23 mm2, a tunable four‐channel system with fr ranging from 400 to 3000 Hz is achieved. This advancement enables the sensing of focused acoustic waves, simulating the functionality of an artificial human ear model.

RAGAM ANAK BERKEBUTUHAN KHUSUS (ABK) DAN PROBLEMATIKA ANAK TUNARUNGU SERTA CARA MENGATASINYA DI SEKOLAH ALAM MAHIRA BENGKULU

&#x0D; The research objective with this study is to explore the Variety of Children with Special Needs (ABK) and the Problems of Deaf Children and How to Overcome Them in the Alam Mahira School Bengkulu. This study uses descriptive qualitative research where direct research is spaciousness. The informants in this study were 2 teacher and 1 student from the Alam Mahira Bengkulu School. This research addresses children with special needs by showing photos, videos, letter cards, sentence cards, ear anatomy, miniature objects, finger alphabet, ear models, half body torsos, fruit puzzles, animal puzzles, construction puzzles, cylinders, models. geometry, triangular tower, ring tower, rectangular tower, atlas, globe, wall map, custom house miniature. The results of the study show that there are several types of children with special needs (ABK) found in the field, including learning dyslexia (learning difficulties), ADHD (difficulty focusing), Autism (nervous disorder), Speech Delay (speech delay), Down Syndrome (physical and mental retardation). ), Mental Impairment (abnormalities below average – IQ), Deaf (hearing impairment). In this study it was more focused on children with special needs of the deaf. The results of the research show that deaf children need learning media in the form of visual aids to enrich their language vocabulary. The visual aids include miniature animals, miniature humans, relevant pictures, illustrated library books, and children's play equipment.

The mTOR Inhibitor Rapamycin Counteracts Follicle Activation Induced by Ovarian Cryopreservation in Murine Transplantation Models.

Background and Objectives: Ovarian tissue cryopreservation followed by autotransplantation (OTCTP) is currently the only fertility preservation option for prepubertal patients. Once in remission, the autotransplantation of frozen/thawed tissue is performed when patients want to conceive. A major issue of the procedure is follicular loss directly after grafting mainly due to follicle activation. To improve follicular survival during the OTCTP procedure, we inhibited the mTOR pathway involved in follicle activation using rapamycin, an mTOR inhibitor. Next, we compared two different in vivo models of transplantation: the recently described non-invasive heterotopic transplantation model between the skin layers of the ears, and the more conventional and invasive transplantation under the kidney capsule. Materials and Methods: To study the effects of adding rapamycin during cryopreservation, 4-week-old C57BL/6 mouse ovaries, either fresh, slow-frozen, or slow-frozen with rapamycin, were autotransplanted under the kidney capsule of mice and recovered three weeks later for immunohistochemical (IHC) analysis. To compare the ear with the kidney capsule transplantation model, fresh 4-week-old C57BL/6 mouse ovaries were autotransplanted to either site, followed by an injection of either LY294002, a PI3K inhibitor, vehicle control, or neither, and these were recovered three weeks later for IHC analysis. Results: Rapamycin counteracts cryopreservation-induced follicle proliferation, as well as AKT and mTOR pathway activation, in ovaries autotransplanted for three weeks under the kidney capsule of mice. Analyses of follicle proliferation, mTOR activation, and the effects of LY294002 treatment were similar in transplanted ovaries using either the ear or kidney capsule transplantation model. Conclusions: By adding rapamycin during the OTCTP procedure, we were able to transiently maintain primordial follicles in a quiescent state. This is a promising method for improving the longevity of the ovarian graft. Furthermore, both the ear and kidney capsule transplantation models were suitable for investigating follicle activation and proliferation and pharmacological strategies.

Pathogenic mechanism analysis of cochlear key structural lesion and phonosensitive hearing loss.

Due to ethical issues and the very fine and complex structure of the cochlea, it is difficult to directly perform experimental measurement on the human cochlea. Therefore, the finite element method has become an effective and replaceable new research means. Accurate numerical analysis on human ear using finite element method can provide better understanding of sound transmission and can be used to assess the influence of diseases on hearing and to treat hearing loss. In this research, a three-dimensional (3D) finite element model (FEM) of the human ear of cochlea was presented to investigate the destruction of basilar membrane (BM), round window (RW) sclerosis and perilymph fistula, the key structures of the cochlea, and analyze the effects of these abnormal pathological states in the cochlea on cochlear hearing, resulting in the changes in cochlear sense structure biomechanical behavior and quantitative prediction of the degree and harm of the disorder to the decline of human hearing. Therefore, this paper can deepen reader's understanding of the cochlear biomechanical mechanism and provide a theoretical foundation for clinical otology.

Binocular microscopes versus exoscopes: Experiences and performance in simulated otologic surgery.

Exoscopes represent a promising alternative to conventional binocular microscopes (OM) in otology offering potential advantages such as enhanced ergonomics and a more compact device design. While previous research has demonstrated the effectiveness of exoscopes in various surgical specialties, their objective assessment in the field of otology remains limited. Therefore, this investigation aims to assess task-based efficiency associated with exoscopes in the field of otology by use of simulated surgical models. A prospective cross-over study design was used to compare an OM to an exoscope in otolaryngology residents and medical students. Participants performed five tasks on 3D-printed ear models using both the exoscope and OM. Data collection included completion time, frequency of predefined errors, mental effort, and user experience. Subgroup analysis was performed based on level of experience. Fourteen students and fifteen residents participated. Participants completed four of five tasks faster with the OM and there was no difference in number of errors committed. When separated by surgical experience, residents performed four of five tasks faster using the OM while students completed one of five tasks faster with the OM. Students committed more errors with the exoscope for one task with no difference in errors for residents. There was no difference in perceived difficulty performing tasks with either visualization system. Exit survey results showed more favorable opinions of the OM among residents and more favorable opinions of the exoscope among students. The exoscope permits successful performance in simulated otologic tasks. Task performance and user experience between operative microscopes and exoscopes differ based on level of surgical experience. 2.

Relative importance and interactions of parameters of finite-element models of human middle ear.

In the last decades, finite-element models of the middle ear have been widely used to predict the middle-ear vibration outputs. Even with the simplest linear assumption for material properties of the structures in the middle ear, these models need tens of parameters. Due to the complexities of measurements of material properties of these structures, accurate estimations of the values of most of these parameters are not possible. In this study, we benefited from the stochastic finite-element model of the middle ear we had developed in the past, to perform global sensitivity analysis. For this aim, we implemented Sobol' sensitivity analysis which ranks the importance of all uncertain parameters and interactions among them at different frequencies. To decrease the computational costs, we found Sobol' indices from surrogate models that we created using stochastic finite-element results and the polynomial chaos expansion method. Based on the results, the Young's modulus and thickness of the tympanic membrane, Young's modulus and damping of the stapedial annular ligaments, and the Young's modulus of ossicles are among the parameters with the greatest impacts on vibrations of the umbo and stapes footplate. Furthermore, the most significant interactions happen between the Young's modulus and thickness of the tympanic membrane.

Improving Monocular Camera Localization for Video-Based Three-Dimensional Outer Ear Reconstruction Tasks

This work addresses challenges related to camera 3D localization while reconstructing a 3D model of an ear. This work explores the potential solution of using a cap, specifically designed not to obstruct the ear, and its efficiency in enhancing the camera localization for structure-from-motion (SfM)-based object reconstruction. The proposed solution is described, and an elaboration of the experimental scenarios used to investigate the background textures is provided; data collection and software tools used in the research are reported. The results show that the proposed method is effective, and using the cap with texture leads to a reduction in the camera localization error. Errors in the 3D location reconstruction of the camera were calculated by comparing cameras localized within typical ear reconstruction situations to those of higher-accuracy reconstructions. The findings also show that caps with sparse dot patterns and a regular knitted patterned winter hat are the preferred patterns. The study provides a contribution to the field of 3D modeling, particularly in the context of creating 3D models of the human ear, and offers a step towards more accurate, reliable, and feasible 3D ear modeling and reconstruction.