Reflection function, reflectance, and area function measurements in ears of children and adults.

The main experiment concerned time-domain measurements of the acoustical reflection function (RF) of the human ear in adults and children (aged 5 to 8 years) using a probe inserted into the ear canal. This RF was used to calculate the area function of the ear canal versus distance along its centerline. Acoustical reflectance was calculated in the frequency domain from the RF, as was the difference in sound pressure level near the tympanic membrane relative to the probe tip. Group responses in area function, total ear-canal length, absorbance and group delay, and admittance magnitude and phase were analyzed based on sex, ear, and age. Responses were compared between children/adults and younger/older adults relative to age 50 years. Ear and sex were never significant. Significant differences were observed in children compared to adults in the area function, absorbance and group delay, and admittance magnitude and phase (0.25-4 kHz). Group delay differed between younger and older adults. A second experiment assessed level dependence of responses to better understand limitations in probe performance observed in the main experiment. These results show the utility of time-domain measurements of the area function and derived reflectance to understand sound-transmission differences across age at frequencies important to middle-ear function.

Refractory Chronic Diffuse Granular Myringitis with Medial Meatal Stenosis.

Granular myringitis is a chronic inflammatory condition of the tympanic membrane that does not involve the middle ear. Various treatment modalities have been proposed for the treatment of granular myringitis, but there is no standard treatment regime. A 60-year-old woman had left persistent ear discharge for 4 months. Examination revealed diffuse granulation tissue, forming a pseudomembrane at the medial aspect of the ear canal and obstructing the tympanic membrane. An audiogram revealed mild-to-moderate left-sided conductive hearing loss. She was treated with multiple courses of ear drop antibiotics but had no improvement. The decision for surgical intervention was driven by the presence of a grade IV medial meatal stenosis, the potential risks associated with prolonged medical management, the distressing impact on the patient's life, and a shared decision-making process. A combined transcanal and postauricular endoscopic approach whereby excision of the granulation tissue, canalplasty, and myringoplasty were performed. She exhibited complete symptom resolution and reported an improved quality of life. This approach yielded successful symptom resolution, highlighting its potential in managing refractory chronic granular myringitis. We aimed to carefully weigh the risks of surgery against its potential benefits in a refractory chronic case, acknowledging the inherent risks and disadvantages of surgical interventions. Further studies are warranted to evaluate the long-term outcomes and benefits of this approach.

Conformal immunomodulatory hydrogels for the treatment of otitis media.

Otitis media (OM), a condition stemming from the proliferation of various bacteria within the tympanic cavity (TC), is commonly addressed through the administration of ofloxacin (OFL), a fluoroquinolone antibiotic. Nevertheless, the escalating issue of antibiotic resistance and the challenge of drug leakage underscore the exploration of an alternative, more effective treatment modality in clinical practice. Here, we introduce a simple and easily implementable fluid-regulated strategy aimed at delivering immunomodulatory hydrogels into the TC, ensuring conformal contact with the irregular anatomical surfaces of the middle ear cavity to more effectively eliminate bacteria and treat OM. This innovative strategy exhibits expedited therapeutic process of antibiotic-resistant, acute and chronic OM rats, and significant reductions in the severity of tympanic membrane (TM) inflammation, residual bacteria within the TC (0.12 *105 CFU), and the thickness of TM/TC mucosa (17.63/32.43 µm), as compared to conventional OFL treatment (3.6, 0.76 *105 CFU, 48.70/151.26 µm). The broad-spectrum antibacterial and antibiofilm properties of this strategy against a spectrum of OM pathogens are demonstrated. The strategy is validated to bolster the host's innate immune response through the stimulation of antibacterial protein synthesis, macrophage proliferation and activation, thereby accelerating bacterial eradication and inflammation resolution within the TC. This facile, cost-effective and in vivo degradable technology exhibits promising prospects for future clinical implementation.

Diagnostic Value of Cone-Beam Computed Tomography in Conductive or Mixed Hearing Loss with Intact Tympanic Membrane.

BACKGROUND: Conductive or mixed hearing loss with an intact tympanic membrane is a group of diseases characterized by similar clinical symptoms. Definitive diagnosis depends on the findings of exploratory tympanic surgery. Cone-beam computed tomography (CBCT) has great potential for middle ear imaging. This study evaluated the diagnostic value of CBCT for conductive or mixed hearing loss with an intact tympanic membrane. METHODS: CBCT and high-resolution computed tomography (HRCT) imaging data were collected from patients with an intact eardrum who received medical treatment in our hospital for conductive or mixed hearing loss from October 2020 to May 2023. The imaging characteristics and diagnostic values of CBCT and HRCT were analyzed. RESULTS: A total of 137 patients who met the inclusion criteria and underwent CBCT were enrolled, including 89 with otosclerosis, 41 with ossicular chain interruption, and 7 with tympanosclerosis. CBCT clearly displayed a middle ear focus, such as low-density lesions located in the fissula ante fenestram, ossicular chain malformation or dislocation, and tympanic calcification foci. The area under the curve values for otosclerosis, ossicular chain interruption, and tympanic sclerosis were 0.934, 0.967, and 0.850, respectively. CBCT was more effective than HRCT for visualizing the lenticular process, incudostapedial joint, and stapes footplate. CONCLUSIONS: CBCT of the middle ear demonstrated higher-quality imaging to improve the diagnosis of conductive or mixed hearing loss with an intact tympanic membrane. Therefore, CBCT is recommended for further investigation of noninflammatory diseases of the middle ear with no special findings on HRCT.

Role of tympanocentesis in the prevention of middle ear barotrauma induced by fast buoyant ascent escape from 200 m underwater.

Introduction: We aimed to study middle ear barotrauma caused by fast compression followed by buoyant ascent escape from 200 m underwater and its effect on the auditory system, and to validate the preventive effect of tympanocentesis on middle ear barotrauma. Methods: Twenty Sprague Dawley rats were divided into two groups: rats in group A underwent a simulated fast buoyant ascent escape from a depth of 200 m, while those in group B underwent tympanocentesis before the procedure described for group A. Ear endoscopy, acoustic conductance, and auditory brainstem response (ABR) tests were conducted before and after the procedure to evaluate the severity of middle ear barotrauma and auditory function in both groups. Additionally, histopathological examination of the middle ear in both groups was conducted to evaluate the severity of middle ear barotrauma by observing submucosal haemorrhage. Results: None of the ears in either group showed any abnormalities before the experiment. In group A, middle ear barotrauma was universally observed after the simulation procedure. The tympanograms of all ears were initially type A and became type B after the procedure. Further, after the simulation, the hearing thresholds at different frequencies (4, 8, 16, 24, and 32 kHz) assessed by ABR significantly increased compared to those before the procedure. In group B, no middle ear barotrauma was observed, and the hearing threshold at each frequency did not change significantly compared with post-puncturing. After dissecting the middle ear, gross pathological observations were consistent with the above results. Microscopically, blood accumulation and submucosal haemorrhage in the middle ear cavity were observed in group A but not in group B. Conclusions: Fast buoyant ascent from 200 m underwater can cause middle ear barotrauma, resulting in hearing loss. Tympanic membrane puncture can effectively prevent middle ear barotrauma caused by the rapid buoyant ascent escape procedure.

Clinical outcome of cats with suppurative otitis media and intact tympanum submitted to myringotomy: retrospective findings from 26 cases.

CASE SERIES SUMMARY: The efficacy of medical treatment associated with single myringotomy in cats with suppurative otitis media (OM) and intact tympanum was retrospectively evaluated. Patients' records were retrieved from cats with suppurative OM. Cats were included in this retrospective study based on fluid content within the tympanic cavity on imaging, intact tympanum on otoendoscopic examination and neutrophils on ear bulla exudate cytological examination. A total of 26 cats with middle ear suppurative otitis were included. Just over half of the cats (54%) presented bilateral involvement. Clinical signs included head tilt (13/26), otalgia (9/26), Horner's syndrome (7/26), external ear discharge (5/26), and nystagmus and facial paralysis (1/26). Cocci were identified on cytological examination in 18/40 samples and rods in 2/40. Bacterial culture results were positive in 15/40 samples, with Pseudomonas species (4/15), Pasteurella multocida (3/15), Staphylococcus felis (3/15), Staphylococcus schleiferi (2/15), Staphylococcus canis (2/15), Escherichia coli (2/15), Staphylococcus pseudintermedius (1/15) and Serratia marcesens (1/15) isolation. After myringotomy and gentle flushing of middle ear bullae (0.5-2 ml saline per ear), all cats were treated with oral corticosteroids and a 1-month course of systemic antibiotics according to sensitivity testing. In total, 19 (73%) cats were clinically healed 60-240 days after treatment. One cat was euthanased because of failure to eradicate a Pseudomonas species infection. Another cat died a few hours after the procedure. The five remaining cats were cured after ventral bulla osteotomy. RELEVANCE AND NOVEL INFORMATION: OM without an aural polyp is a frequent diagnosis in cats, but data on medical treatment are scarce. This simple therapeutic technique, single myringotomy procedure and mild ear flushing, offers a practical, safe and efficient first-line treatment of suppurative OM with an intact tympanum in cats with or without neurological signs.

Tympanic Membrane Regeneration Therapy for Pediatric Tympanic Membrane Perforation.

OBJECTIVE: To evaluate tympanic membrane regeneration therapy (TMRT) for pediatric tympanic membrane perforations (TMPs). STUDY DESIGN: Intervention study. SETTING: Research institute hospital. PATIENTS: In this study, 20 patients with chronic TMP (M/F: 13/7, 13/8 ears, age 0-15 years) treated with TMRT were evaluated. As comparison, 20 pediatric patients with chronic TMP who underwent myringoplasty/tympanoplasty were included. INTERVENTIONS: For the TM repair procedure, the edge of the TMP was disrupted mechanically, and gelatin sponge immersed in basic fibroblast growth factor was placed inside and outside the tympanic cavity and covered with fibrin glue. The TMP was examined 4 ± 1 weeks later. The protocol was repeated up to four times until closure was complete. MAIN OUTCOME MEASURES: Closure of the TMP and hearing improvement were evaluated at 16 weeks after the final regenerative procedure. Adverse events were monitored. RESULTS: The mean follow-up period was 427.1 days. The TM regenerated in all cases, but pinhole reperforation occurred in two cases, and the final closure rate was 90.5% (19 of 21). Hearing improved to 24.9 ± 7.6 dB on average before surgery and to 13.8 ± 5.4 dB after surgery. The AB gap improved from 12.9 ± 8.0 to 5.2 ± 3.5 dB.The myringoplasty/tympanoplasty group had significantly lower AB gap improvement compared with the TMRT group. There were no adverse events. CONCLUSIONS: TMRT can be expected to regenerate near-normal TMs with a high closure ratio, resulting in better-hearing improvement compared with the myringoplasty/tympanoplasty group, and is an effective treatment for children with long life expectancy.

Optical coherence tomography otoscope for imaging of tympanic membrane and middle ear pathology.

Significance: Pathologies within the tympanic membrane (TM) and middle ear (ME) can lead to hearing loss. Imaging tools available in the hearing clinic for diagnosis and management are limited to visual inspection using the classic otoscope. The otoscopic view is limited to the surface of the TM, especially in diseased ears where the TM is opaque. An integrated optical coherence tomography (OCT) otoscope can provide images of the interior of the TM and ME space as well as an otoscope image. This enables the clinicians to correlate the standard otoscopic view with OCT and then use the new information to improve the diagnostic accuracy and management. Aim: We aim to develop an OCT otoscope that can easily be used in the hearing clinic and demonstrate the system in the hearing clinic, identifying relevant image features of various pathologies not apparent in the standard otoscopic view. Approach: We developed a portable OCT otoscope device featuring an improved field of view and form-factor that can be operated solely by the clinician using an integrated foot pedal to control image acquisition. The device was used to image patients at a hearing clinic. Results: The field of view of the imaging system was improved to a 7.4 mm diameter, with lateral and axial resolutions of 38 µ m and 33.4 µ m , respectively. We developed algorithms to resample the images in Cartesian coordinates after collection in spherical polar coordinates and correct the image aberration. We imaged over 100 patients in the hearing clinic at USC Keck Hospital. Here, we identify some of the pathological features evident in the OCT images and highlight cases in which the OCT image provided clinically relevant information that was not available from traditional otoscopic imaging. Conclusions: The developed OCT otoscope can readily fit into the hearing clinic workflow and provide new relevant information for diagnosing and managing TM and ME disease.

Finite-element modelling of interactions of needle with tympanic membrane and middle ear.

The tympanic membrane (TM) is one of the most common routes to access the middle ear and inner ear for the treatment of hearing and balance pathologies. Since the TM is a soft thin biological tissue with small dimensions, using needles seems to be among the most practical interventional approaches. In this study, we proposed a finite-element (FE) analysis of needle-TM interactions that combines a 3D model of the TM and other main middle-ear structures in gerbil, and a 2D model of needle insertion into the TM based on the cohesive zone method (CZM). The TM was modelled using a 1st-order Ogden hyperelastic material and its properties were obtained by fitting to the experimental force-displacement plots of large deformation in the TM under needle indentation. The cohesive parameters were also acquired by calibrating the puncture force against the experimental data of needle insertion into the TM. These FE models were then used to obtain the deformation behaviour of the TM and other middle-ear structures due to the insertion force applied at different locations on the TM. Moreover, we investigated the effect of the TM thickness, the geometry of the needle (i.e., diameter and tip angle), and needle material on the insertion of needles into the TM. We also studied the penetration success of deformable needles.

[Tympanoplasty with and without mastoidectomy for the treatment of active efficacy analysis of chronic suppurative otitis media of simple type].

Objective:To analyze the surgical efficacy and safety of tympanoplasty with and without mastoidectomy for the treatment of active simple chronic suppurative otitis media（CSOM）, and to investigate whether mastoidectomy can be avoided in tympanoplasty for active CSOM. Methods:The clinical data of 55 patients（55 ears） with active CSOM were retrospectively analyzed. Based on the development of the mastoid process and the upper tympanic chamber, patients who met the criteria for wall-up mastoidectomy were classified as group A （30 patients）, and underwent tympanoplasty combined with wall-up mastoidectomy. Patients who did not meet the criteria for wall-up mastoidectomy were classified as group B（25 cases）, and underwent tympanoplasty with the opening of the middle and upper tympanic chambers and sinus drainage after partial removal of the shield plate bone. The survival rate of tympanic membrane grafts, hearing before and after surgery, and complications such as reperforation were compared between the two groups at 3 months postoperatively. Results:The overall postoperative tympanic membrane survival rate of patients with active CSOM was 96.4%（53/55）, including 96.7% in group A; 96.0% in group B. There was no significant difference in the tympanic membrane survival rate between the two groups（P>0.05）. The postoperative mean air-bone gap（ABG） was significantly reduced in both groups compared with the preoperative period, but there was no significant difference in ABG gain between the two groups（P>0.05）. No patients experienced serious adverse conditions such as peripheral facial paralysis, cerebrospinal fluid leakage, or sensorineural deafness after surgery. Conclusion:Microscopic tympanoplasty with patency of the middle and upper tympanic chambers and tympanic sinus drainage can be used to treat active simple chronic otitis media with satisfactory tympanic membrane viability and hearing improvement efficacy. This approach reduces patient trauma, prevents complications such as skin depressions in the mastoid area due to abrasion of the mastoid bone, and shortens the waiting time before surgery.

Biomaterials for non-invasive trans-tympanic drug delivery: requirements, recent advances and perspectives.

Various non-invasive delivery systems have recently been developed as an alternative to conventional injections. Local transdermal administration represents the most attractive method due to the low systemic side effects, excellent ease of administration, and persistent drug release. The tympanic membrane (TM), a major barrier between the outer and middle ear, has a similar structure of the stratum corneum compared to the surface of the skin. After several attempts, non-invasive trans-tympanic drug delivery has been regarded as a promising option in the treatment of middle and inner ear diseases. The round window membrane (RWM) was a possible non-invasive delivery approach from the middle to inner ear. The improved permeability of nanocarriers crossing the RWM is a current hotspot in therapeutics for inner ear diseases. In this review, we include the latest studies exploring non-invasive trans-tympanic delivery to treat middle and inner ear diseases. Both passive and active delivery systems are described. A summary of the benefits and disadvantages of various delivery systems in clinical practice and production procedures is introduced. Finally, future possible approaches for its effective application as a non-invasive middle and inner ear drug delivery system are characterised.

Fabrication and Evaluation of Hyaluronidase-Responsive Scaffolds by Electrospinning with Antibacterial Properties for Tympanic Membrane Repair.

Tympanic membrane perforation (TMP) is prevalent in clinical settings. Patients with TMPs often suffer from infections caused by Staphylococcus aureus and Pseudomonas aeruginosa, leading to middle ear and external ear canal infections, which hinder eardrum healing. The objective of this study is to fabricate an enzyme-responsive antibacterial electrospun scaffold using poly(lactic-co-glycolic acid) and hyaluronic acid for the treatment of infected TMPs. The properties of the scaffold were characterized, including morphology, wettability, mechanical properties, degradation properties, antimicrobial properties, and biocompatibility. The results indicated that the fabricated scaffold had a core-shell structure and exhibited excellent mechanical properties, hydrophobicity, degradability, and cytocompatibility. Furthermore, in vitro bacterial tests and ex vivo investigations on eardrum infections suggested that this scaffold possesses hyaluronidase-responsive antibacterial properties. It may rapidly release antibiotics when exposed to the enzyme released by S. aureus and P. aeruginosa. These findings suggest that the scaffold has great potential for repairing TMPs with infections.

Coupled membranes: a mechanism of frequency filtering and transmission in the field cricket ear evidenced by micro-computed tomography, laser Doppler vibrometry and finite element analysis.

Many animals employ a second frequency filter beyond the initial filtering of the eardrum (or tympanal membrane). In the field cricket ear, both the filtering mechanism and the transmission path from the posterior tympanal membrane (PTM) have remained unclear. A mismatch between PTM vibrations and sensilla tuning has prompted speculations of a second filter. PTM coupling to the tracheal branches is suggested to support a transmission pathway. Here, we present three independent lines of evidence converging on the same conclusion: the existence of a series of linked membranes with distinct resonant frequencies serving both filtering and transmission functions. Micro-computed tomography (µ-CT) highlighted the 'dividing membrane (DivM)', separating the tracheal branches and connected to the PTM via the dorsal membrane of the posterior tracheal branch (DM-PTB). Thickness analysis showed the DivM to share significant thinness similarity with the PTM. Laser Doppler vibrometry indicated the first of two PTM vibrational peaks, at 6 and 14 kHz, originates not from the PTM but from the coupled DM-PTB. This result was corroborated by µ-CT-based finite element analysis. These findings clarify further the biophysical source of neuroethological pathways in what is an important model of behavioural neuroscience. Tuned microscale coupled membranes may also hold biomimetic relevance.

Differential effects of mass-loading the eardrum and stiffening the middle ear on wideband absorbance.

The current work investigated the effects of mass-loading the eardrum on wideband absorbance in humans. A non-invasive approach to mass-loading the eardrum was utilized in which water was placed on the eardrum via ear canal access. The mass-loaded absorbance was compared to absorbance measured for two alternative middle ear states: normal and stiffened. To stiffen the ear, subjects pressurized the middle ear through either exsufflation or insufflation concurrent with Eustachian tube opening. Mass-loading the eardrum was hypothesized to reduce high-frequency absorbance, whereas pressurizing the middle ear was hypothesized to reduce low- to mid-frequency absorbance. Discriminant linear analysis classification was performed to evaluate the utility of absorbance in differentiating between conditions. Water on the eardrum reduced absorbance over the 0.7- to 6-kHz frequency range and increased absorbance at frequencies below approximately 0.5 kHz; these changes approximated the pattern of changes reported in both hearing thresholds and stapes motion upon mass-loading the eardrum. Pressurizing the middle ear reduced the absorbance over the 0.125- to 4-kHz frequency range. Several classification models based on the absorbance in two- or three-frequency bands had accuracy exceeding 88%.

Pediatric tympanostomy tube assessment via deep learning.

PURPOSE: Tympanostomy tube (TT) placement is the most frequently performed ambulatory surgery in children under 15. After the procedure it is recommended that patients follow up regularly for "tube checks" until TT extrusion. Such visits incur direct and indirect costs to families in the form of days off from work, copays, and travel expenses. This pilot study aims to compare the efficacy of tympanic membrane (TM) evaluation by an artificial intelligence algorithm with that of clinical staff for determining presence or absence of a tympanostomy tube within the TM. METHODS: Using a digital otoscope, we performed a prospective study in children (ages 10 months-10 years) with a history of TTs who were being seen for follow up in a pediatric otolaryngology clinic. A smartphone otoscope was used by study personnel who were not physicians to take ear exam images, then through conventional otoscopic exam, ears were assessed by a clinician for tubes being in place or tubes having extruded from the TM. We trained and tested a deep learning (artificial intelligence) algorithm to assess the images and compared that with the clinician's assessment. RESULTS: A total of 123 images were obtained from 28 subjects. The algorithm classified images as TM with or without tube in place. Overall classification accuracy was 97.7 %. Recall and precision were 100 % and 96 %, respectively, for TM without a tube present, and 95 % and 100 %, respectively, for TM with a tube in place. DISCUSSION: This is a promising deep learning algorithm for classifying ear tube presence in the TM utilizing images obtained in awake children using an over-the-counter otoscope available to the lay population. We are continuing enrollment, with the goal of building an algorithm to assess tube patency and extrusion.

Effects of Tympanic Membrane Electrodes on Sound Transmission From the Ear Canal to the Middle and Inner Ears.

OBJECTIVES: The first objective of the study was to compare approaches to eardrum electrode insertion as they relate to the likelihood of introducing an acoustic leak between the ear canal and eartip. A common method for placing a tympanic membrane electrode involves securing the electrode in the canal by routing it underneath a foam eartip. This method is hypothesized to result in a slit leak between the canal and foam tip due to the added bulk of the electrode wire. An alternative approach involves creating a bore in the wall of the foam tip that the electrode can be threaded through. This method is hypothesized to reduce the likelihood of a slit leak before the electrode wire is integrated into the foam tip. The second objective of the study was to investigate how sound transmission in the ear is affected by placing an electrode on the eardrum. It was hypothesized that an electrode in contact with the eardrum increases the eardrum's mass, with the potential to reduce sound transmission at high frequencies. DESIGN: Wideband acoustic immittance and distortion product otoacoustic emissions (DPOAEs) were measured in eight human ears. Measurements were completed for five different conditions: (1) baseline with no electrode in the canal, (2) dry electrode in the canal but not touching the eardrum, secured underneath the eartip, (3) dry electrode in the canal not touching the eardrum, secured through a bore in the eartip (subsequent conditions were completed using this method), (4) hydrated electrode in the canal but not touching the eardrum, and (5) hydrated electrode touching the eardrum. To create the bore, a technique was developed in which a needle is heated and pushed through the foam eartip. The electrode is then thread through the bore and advanced slowly by hand until contacting the eardrum. Analysis included comparing absorbance, admittance phase angle, and DPOAE levels between measurement conditions. RESULTS: Comparison of the absorbance and admittance phase angle measurements between the electrode placement methods revealed significantly higher absorbance and lower admittance phase angle from 0.125 to 1 kHz when the electrode is routed under the eartip. Absorbance and admittance phase angle were minimally affected when the electrode was inserted through a bore in the eartip. DPOAE levels across the different conditions showed changes approximating test-retest variability. Upon contacting the eardrum, the absorbance tended to decrease below 1 kHz and increase above 1 kHz. However, changes were within the range of test-retest variability. There was evidence of reduced levels below 1 kHz and increased levels above 1 kHz upon the electrode contacting the eardrum. However, differences between conditions approximated test-retest variability. CONCLUSIONS: Routing the eardrum electrode through the foam tip reduces the likelihood of incurring an acoustic leak between the canal walls and eartip, compared with routing the electrode under the eartip. Changes in absorbance and DPOAE levels resulting from electrode contact with the eardrum implicate potential stiffening of eardrum; however, the magnitude of changes suggests minimal effect of the electrode on sound transmission in the ear.

A Pseudo-Surfactant Chemical Permeation Enhancer to Treat Otitis Media via Sustained Transtympanic Delivery of Antibiotics.

Chemical permeation enhancers (CPEs) represent a prevalent and safe strategy to enable noninvasive drug delivery across skin-like biological barriers such as the tympanic membrane (TM). While most existing CPEs interact strongly with the lipid bilayers in the stratum corneum to create defects as diffusion paths, their interactions with the delivery system, such as polymers forming a hydrogel, can compromise gelation, formulation stability, and drug diffusion. To overcome this challenge, differing interactions between CPEs and the hydrogel system are explored, especially those with sodium dodecyl sulfate (SDS), an ionic surfactant and a common CPE, and those with methyl laurate (ML), a nonionic counterpart with a similar length alkyl chain. Notably, the use of ML effectively decouples permeation enhancement from gelation, enabling sustained delivery across TMs to treat acute otitis media (AOM), which is not possible with the use of SDS. Ciprofloxacin and ML are shown to form a pseudo-surfactant that significantly boosts transtympanic permeation. The middle ear ciprofloxacin concentration is increased by 70-fold in vivo in a chinchilla AOM model, yielding superior efficacy and biocompatibility than the previous highest-performing formulation. Beyond improved efficacy and biocompatibility, this single-CPE formulation significantly accelerates its progression toward clinical deployment.

Half canal wall down tympanomastoidectomy.

OBJECTIVE: The purpose of this study is to analyse the effect of half canal wall down tympanomastoidectomy in the treatment of chronic otitis media or cholesteatoma. METHOD: In this retrospective study, the half canal wall down tympanomastoidectomy technique was used at our hospital for chronic otitis media or cholesteatoma removal in 265 adult patients, representing 271 operated ears, with an average follow-up time of 8.4 years. RESULTS: The post-operative cavities were slightly wider and straighter in 91.9 per cent of the ears. Fifteen per cent of the patients needed cavity cleaning every six months, 25 per cent of them needed cavity cleaning every year and 60 per cent of the patients had a self-cleaning cavity. Only one patient with a cleft palate experienced cholesteatoma recurrence in the mesotympanum. CONCLUSION: The half canal wall down tympanomastoidectomy technique showed a low-recurrence rate and satisfying operative cavities. The half canal wall down tympanomastoidectomy technique is a good choice for middle ear surgery.

Mechanical Effects of Medical Device Attachment to Human Tympanic Membrane.

PURPOSE: Several treatment methods for hearing disorders rely on attaching medical devices to the tympanic membrane. This study aims to systematically analyze the effects of the material and geometrical properties and location of the medical devices attached to the tympanic membrane on middle-ear vibrations. METHODS: A finite-element model of the human middle ear was employed to simulate the effects of attachment of medical devices. Various types of material and geometrical properties, locations, and modeling scenarios were investigated for the medical device. RESULTS: The attachment of the device magnifies the effects of anti-resonances of the middle ear. Additionally, the variations of the material properties of the device significantly alter the middle-ear resonance frequency while changes in the umbo and stapes footplate motions are negligible at frequencies above 5 kHz. Furthermore, modeling the device as a point mass cannot accurately represent the implanted middle-ear behavior. The variations of the diameter and height of the medical device have negligible effects on the middle-ear vibrations at frequencies below 200 Hz but can have considerable impacts at higher frequencies. The effects of changing the device height were negligible at frequencies above 2 kHz. We also discuss the effects of medical device attachment on the vibration patterns of the tympanic membrane as well as the impacts of the variations of the location of the device on the stapes footplate responses. CONCLUSION: The findings of our study aid the development and optimization of new therapeutic devices, attached to the tympanic membrane, to have the least adverse effects on middle-ear vibrations.

Semi-automatic algorithm to build finite element numerical models of the human hearing system from Micro-CT data.

Finite Element modeling has been an extended methodology to build numerical model to simulate the behavior of the hearing system. Due to the complexity of the system and the difficulties to reduce the uncertainties of the geometric data, they result in computationally expensive models, sometimes generic, representative of average geometries. It makes it difficult to validate the model with direct experimental data from the same specimen or to establish a patient-oriented modeling strategy. In the present paper, a first attempt to automatize the process of model building is made. The source information is geometrical information obtained from CT of the different elements that compose the system. Importing that data, we have designed the complete procedure to build a model including tympanic membrane, ossicular chain and cavities. The methodology includes the proper coupling of all the elements and the generation of the corresponding finite element model. The whole automatic procedure is not complete, as we need to make some human-assisted decisions; however, the model development time is reduced from 4 weeks to approximately 3 days. The goal of the modeling algorithm is to build a Finite Element Model with a limited computational cost. Several tasks as contour identification or model decimation are designed and integrated in order to follow a semi-automated process that allows generating a patient-oriented model.