Impact of Coupling Techniques of an Active Middle Ear Device to the Round Window Membrane for the Backward Stimulation of the Cochlea

A case of sudden deafness due to rupture of the round window membrane is presented. Nineteen similar cases have previously been reported in the literature. In a review of these twenty patients, it is noted that a history of concurrent physical effort or barotrauma was present in eighteen. This supports the view that the injury is produced by pressure changes acting either along the cochlear aqueduct (the explosive route) or, directly on the middle ear structures (the implosive route). At operation, the rupture may be difficult to see, and a separate leak from the oval window may be present. The timing of any surgical intervention is important. The authors recommend that this should be deferred for one week after the onset of symptoms, as the fistula may heal spontaneously. If no definite improvement has occurred at the end of this time, then tympanotomy should be undertaken during the next week.

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Round Window Membrane in Serous and Purulent Otitis Media: Structural Study in the Rat

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348949310200311 ◽

1993 ◽

Vol 102 (3) ◽

pp. 227-235 ◽

Cited By ~ 14

Author(s):

Ulf Johansson ◽

Sten Hellström ◽

Matti Anniko

Keyword(s):

Otitis Media ◽

Middle Ear ◽

Structural Changes ◽

Round Window ◽

Inflammatory Cells ◽

Elastic Fibers ◽

Round Window Membrane ◽

Connective Tissue Layer ◽

Structural Alterations ◽

Inflammatory Conditions

The rat was used as an animal model to reveal structural alterations in the round window membrane (RWM) during serous otitis media (SOM) and purulent otitis media (POM) over a 6-week period. Comparison of POM animals and control animals showed that the RWM in the former became almost six times as thick as that in controls, whereas that of SOM animals was twice as thick. The structural changes in the RWM in POM animals were confined mainly to the epithelium facing the middle ear cavity and the subepithelial space, which was invaded by inflammatory cells and exhibited dilated vessels. The normal flat epithelium was transformed via cuboidal cells to a cylindric epithelium containing both ciliated and goblet cells. In SOM animals, light microscopy revealed only minor changes in the RWM structure. Ultrastructurally, however, the connective tissue layer exhibited dense aggregations of collagen, increased numbers of fibroblasts, and, in one case, elastic fibers. This last phenomenon was not observed in either POM ears or normal ears. The study showed that various inflammatory conditions of the middle ear, both noninfectious (SOM) and infectious (POM), can cause different structural alterations of the RWM. These structural changes may influence passage through the RWM differently.

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Round Window Membrane and Perilymph in Experimental Otitis Media with Effusion

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348948909801212 ◽

1989 ◽

Vol 98 (12) ◽

pp. 980-987 ◽

Cited By ~ 8

Author(s):

Masashi Suzuki ◽

Tatsuya Fujiyoshi ◽

Hideyuki Kawauchi ◽

Goro Mogi

Keyword(s):

Otitis Media ◽

Normal Control ◽

Middle Ear ◽

Immune Complexes ◽

Otitis Media With Effusion ◽

Round Window ◽

Round Window Membrane ◽

Prostaglandin E ◽

The Mean ◽

Ear Effusion

To investigate the influence of middle ear effusion (MEE) on perilymph (PL), an experimental otitis media with effusion (OME) was manufactured in chinchillas by injecting the tympanic cavity with immune complexes. The presence of MEE lasted for up to 9 days after the injection of immune complexes. Perilymph was aspirated on the fourth, tenth, and 21st days after the inoculation. The mean concentrations of albumin, immunoglobulin G, histamine, and prostaglandin E2 (PGE2) were significantly greater in PL from ears with induced OME than in that from normal control ears. The 3H-PGE2 placed on the round window membrane of pathologically affected ears passed into PL in significantly greater amounts than in normal control ears. The findings indicate that the immune complexes placed in the middle ear cavity affect the biochemical milieu of PL, and that MEE is a result of immune complexes.

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Application of the Vibrant Soundbridge middle-ear implant for aural atresia in patients with Treacher Collins syndrome

The Journal of Laryngology & Otology ◽

10.1017/s0022215112002344 ◽

2012 ◽

Vol 126 (12) ◽

pp. 1216-1223 ◽

Cited By ~ 10

Author(s):

E Lesinskas ◽

V Stankeviciute ◽

M Petrulionis

Keyword(s):

Middle Ear ◽

Round Window ◽

Treacher Collins Syndrome ◽

Round Window Membrane ◽

Vibrant Soundbridge ◽

Aural Atresia ◽

Middle Ear Implant ◽

Radiological Score ◽

The Mean ◽

Functional Gain

AbstractObjective:To present results for the auditory rehabilitation of patients with Treacher Collins syndrome with bilateral osseous atresia, using middle-ear implantation with a Vibrant Soundbridge.Methods:Three patients underwent vibroplasty for aural atresia with moderate to severe conductive hearing loss. The pre-operative Jahrsdoerfer radiological score was 4 for all patients. Patients underwent active middle-ear implantation of a Vibrant Soundbridge implant (coupling the floating mass transducer to the rudimentary stapes or footplate distally, and positioning it adjacent to the round window membrane proximally), with audiological analysis as follow up.Results:After implant activation, the mean air conduction threshold ± standard deviation decreased to 22.8 ± 5.5 dB HL, representing a mean functional gain of 44.5 dB. The mean word recognition score (for bisyllabic words at 65 dB SPL) increased from 0 to 97 per cent.Conclusion:Vibrant Soundbridge implantation is an effective hearing rehabilitation procedure in patients with Treacher Collins syndrome with bilateral osseous atresia. This is a versatile implant which can achieve coupling even in cases of severe middle-ear malformation.

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Middle Ear Infection Postimplantation: Response of the round Window Membrane to Streptococcus Pyogenes

Annals of Otology Rhinology & Laryngology ◽

10.1177/00034894870960s124 ◽

1987 ◽

Vol 96 (1_suppl) ◽

pp. 53-54 ◽

Cited By ~ 9

Author(s):

N. E. Cranswick ◽

B. K-H. Franz ◽

G. M. Clark ◽

R. K. Shepherd ◽

D. M. Bloom

Keyword(s):

Inflammatory Response ◽

Inner Ear ◽

Streptococcus Pyogenes ◽

Middle Ear ◽

Round Window ◽

Round Window Membrane ◽

Ear Infection ◽

Mechanical Disruption ◽

Middle Ear Infection ◽

Pass Through

The seal of the implanted round window membrane to resist Streptococcus pyogenes invasion from the middle ear was investigated in 12 cats. Results showed that the implanted round window membrane is able to form a barrier for S pyogenes starting 1 week postimplantation. Under normal conditions S pyogenes did not pass through the round window membrane, nor through the gap that existed between the membrane and the prosthesis. Mechanical disruption of the round window seal, however, and severe inflammatory response to S pyogenes caused the infection to extend into the inner ear.

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FINITE ELEMENT ANALYSIS OF THE EFFECT OF ACTUATOR COUPLING CONDITIONS ON ROUND WINDOW STIMULATION

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519415500487 ◽

2015 ◽

Vol 15 (04) ◽

pp. 1550048 ◽

Cited By ~ 7

Author(s):

JIABIN TIAN ◽

XINSHENG HUANG ◽

ZHUSHI RAO ◽

NA TA ◽

LIFU XU

Keyword(s):

Finite Element ◽

Middle Ear ◽

Round Window ◽

Round Window Membrane ◽

Fe Model ◽

Ear Canal ◽

Sound Stimulation ◽

Fe Method ◽

Coupling Conditions ◽

Intracochlear Pressure

The finite element (FE) method was used to analyze the effect of coupling conditions between the actuator and the round window membrane (RWM) on the performance of round window (RW) stimulation. A FE model of the human ear consisting of the external ear canal, middle ear and cochlea was firstly developed, and then validation of this model was accomplished through comparison between analytical results and experimental data in the literature. Intracochlear pressure were derived from the model under normal forward sound stimulation and reverse RW stimulation. The equivalent sound pressure of RW stimulation was then calculated via comparing the differential intracochlear pressure produced by the actuator and normal ear canal sound stimulus. The actuator was simulated as a floating mass and placed onto the middle ear cavity side of RWM. Two aspects about the actuator coupling conditions were considered in this study: (1) the cross-section area of the actuator relative to the RWM; (2) the coupling layer between the actuator and the RWM. The results show that smaller actuator size can improve the implant performance of RW stimulation, and size requirements of the actuator can also be reduced by introducing a coupling layer between the actuator and RWM, which will benefit the manufacture of the actuator.

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The conical cartilage of the cat's middle ear

The Journal of Laryngology & Otology ◽

10.1017/s0022215100097772 ◽

1985 ◽

Vol 99 (9) ◽

pp. 831-838 ◽

Cited By ~ 1

Author(s):

Mahmoud A. Khalil ◽

Myron Spector

Keyword(s):

Tympanic Membrane ◽

Middle Ear ◽

Round Window ◽

Fibrous Tissue ◽

Round Window Membrane ◽

Chorda Tympani Nerve ◽

Arch Bar ◽

Extensive Calcification ◽

Conical Structure ◽

Round Window Niche

AbstractThe object of this study was to investigate the anatomy, histology, and possible function of a conical structure found in the middle ear of the cat. This conical structure lies across the dorso-caudal compartment of the middle ear. It is directly related to the course of the chorda tympani nerve in the middle ear. Its base is attached by fibrous tissue to the dorso-caudal segment of the tympanic bone adjacent to the tympanic membrane. Its apex rests on the promontory just rostral to the round window niche. Histologically, it is cartilaginous tissue enveloped by a mudous membrane with no trace of bone. Portions of some conical cartilage specimens display extensive calcification. A previous hypothesis suggests that this structure conducts high frequency sounds directly from the tympanic membrane to the round window membrane. This seems unlikely because its length is shorter than the distance between the tympanic membrane and round window membrane. The conical cartilage may be a vestigial remnant of the second arch bar (Reichert's cartilage).

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The Influence of Piezoelectric Transducer Stimulating Sites on the Performance of Implantable Middle Ear Hearing Devices: A Numerical Analysis

Micromachines ◽

10.3390/mi10110782 ◽

2019 ◽

Vol 10 (11) ◽

pp. 782 ◽

Cited By ~ 1

Author(s):

Liu ◽

Zhao ◽

Yang ◽

Rao

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Middle Ear ◽

Hearing Aids ◽

Piezoelectric Transducer ◽

Basilar Membrane ◽

Round Window ◽

Element Model ◽

Round Window Membrane ◽

Hearing Devices

To overcome the inherent deficiencies of hearing aids, implantable middle ear hearing devices (IMEHDs) have emerged as a new treatment for hearing loss. However, clinical results show that the IMEHD performance varies with its transducer’s stimulating site. To numerically analyze the influence of the piezoelectric transducer’s stimulating sites on its hearing compensation performance, we constructed a human ear finite element model and confirmed its validity. Based on this finite element model, the displacement stimulation, which simulates the piezoelectric transducer’s stimulation, was applied to the umbo, the incus long process, the incus body, the stapes, and the round window membrane, respectively. Then, the stimulating site’s effect of the piezoelectric transducer was analyzed by comparing the corresponding displacements of the basilar membrane. Besides, the stimulating site’s sensitivity to the direction of excitation was also studied. The result of the finite element analysis shows that stimulating the incus body is least efficient for the piezoelectric transducer. Meanwhile, stimulating the round window membrane or the stapes generates a higher basilar membrane displacement than stimulating the eardrum or the incus long process. However, the performance of these two ideal sites’ stimulation is sensitive to the changes in the excitation’s direction. Thus, the round window membrane and the stapes is the ideal stimulating sites for the piezoelectric transducer regarding the driving efficiency. The direction of the excitation should be guaranteed for these ideal sites.

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Endoscopic visualisation of the round window during cochlear implantation

The Journal of Laryngology & Otology ◽

10.1017/s0022215120000067 ◽

2020 ◽

Vol 134 (3) ◽

pp. 219-221 ◽

Cited By ~ 1

Author(s):

A Jain ◽

R Sharma ◽

J C Passey ◽

R Meher ◽

R Bansal

Keyword(s):

Middle Ear ◽

Cochlear Implantation ◽

Round Window ◽

Electrode Array ◽

Round Window Membrane ◽

Window Region ◽

Round Window Niche ◽

Window Approach ◽

Maximum Exposure

AbstractBackgroundEndoscopes provide a magnified view of the middle ear and visualisation of hidden areas. Otoendoscopes facilitate excellent visualisation of the round window niche during cochlear implantation.ObjectiveTo compare microscopic and endoscopic visualisation of the round window membrane during cochlear implantation in 20 patients.MethodsTwenty patients who underwent cochlear implantation were included in the study. After maximum exposure of the round window, the accessibility of the round window membrane was graded according to the St Thomas Hospital classification, first by microscope and then by endoscope.ResultsWith the use of the endoscope, visualisation of the round window membrane improved in all the patients as compared to the microscope. The electrode array was inserted via a round window or extended round window approach in all but two cases; the latter cases required bony cochleostomy because of unfavourable anatomy.ConclusionThe main benefit of endoscope-assisted cochlear implantation is improved visibility of the round window region.

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