• Korean Journal of Audiology
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• v.24 no.4
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• pp.161-166
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• 2020

Congenital aural atresia is an ear malformation evident at birth, involving various degrees of failed external ear canal development. A true external ear canal is desirable, as devices that replace the canal are inconvenient and expensive. Therefore, an optimal surgical technique is required. Here, we review useful preoperative and operative techniques. Surgical correction is often not the preferred treatment; the hearing outcome is no better than the outcomes afforded by bone-conduction devices, and surgery may be associated with recurrence or complications such as meatal stenosis. Preoperative evaluation and appropriate management are important. Several means of preventing meatal stenosis are discussed in this review.

• Journal of Audiology & Otology
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• v.24 no.4
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• pp.161-166
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• 2020

Congenital aural atresia is an ear malformation evident at birth, involving various degrees of failed external ear canal development. A true external ear canal is desirable, as devices that replace the canal are inconvenient and expensive. Therefore, an optimal surgical technique is required. Here, we review useful preoperative and operative techniques. Surgical correction is often not the preferred treatment; the hearing outcome is no better than the outcomes afforded by bone-conduction devices, and surgery may be associated with recurrence or complications such as meatal stenosis. Preoperative evaluation and appropriate management are important. Several means of preventing meatal stenosis are discussed in this review.

• Journal of Biomedical Engineering Research
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• v.31 no.1
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• pp.20-26
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• 2010

The aim of this study was to test the feasibility of a wireless transceiver that can be inserted into the ear canal. The wireless technology could minimize the cosmetic problems of patients, and it can be applied to binaural hearing aids for improving speech perception. In order to implement the ear canal insertable transceiver, simple finite-difference time-domain (FDTD) simulations were carried out to determine the feasibility, and the hardware of the transceiver was implemented within the ear shell. The size of the implemented transceiver was only $7{\times}7mm$, and it could successfully transmit signals to external devices. In order to measure the radiation pattern, a simple RF phantom was used, and the maximum attenuation from the phantom was observed to be 23 dB when the reference antenna was placed at a distance of 2 m from the transmitter.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.382-385
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• 2005

The aim of this study was to compare ultrasonography with video-otoscopy for the evalution of the external ear canal and the tympanum. Fifty dogs with clinical signs ot the bilateral ear diseases were examined using otoscopy under general anesthesia. Ultrasonographic examination was performed with an 11 MHz linear-arrary probe and a 6.5MHz convex probe, with the external ear canal filled with saline. Saline functioned as a contrast media and enhanced image quality of ultrasonography. The images of 100 ears before and after the ear cleansing were obtained at otoscopy and ultrasonography. On the video-otoscopic images, the tympanic membrane was identified in 59 ears before the ear cleansing and 91 ears after cleansing. On the ultrasonography, the tympanic membrane was detected in 98 ears before the ear cleansing and in all ears after cleansing. With these results, it was concluded that ultrasonography with infusing saline into the ear canal, could be a useful diagnostic procedure to identify the tympanic membrane in otitis dogs.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.173-179
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• 2019

DICOM(Digital Imaging and Communications in Medicine) imaging plays a significant role in the diagnosis and treatment of the human body, and design modeling is a technology of planning shapes in three dimensions according to the purpose. In this study, we converge these two technologies to observe the relationships of the cross-section, volume, and surface area to the morphological changes of the external ear canal. The experiment applied medical imaging technologies to acquire sections of the human body to create and divide centerlines using 3D shapes extracted from 19 external ear canals by applying stereolithography and 3-matic program. The results showed that the cross-sectional structure of the external ear canal had various shapes, such as oval (38.5%), semicircular (28.2%), mixed (17.9%), square (10.2%), and wrinkled (5.1%). In addition, the cross-sectional area of each phase increased as the length of the external ear canal increased, and the volume and surface area decreased towards the direction of the eardrum. However, the surface area reduction rate was relatively low. This indicates that the structure becomes irregular towards the direction of the eardrum.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.396-398
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• 2003

A 2 year-old, 3.8 kg, intact female Maltese was presented with unilateral pain and reddish discharge from the left ear caused by a polyp in the horizontal ear canal. The polyp was diagnosed as osteoma histopathologically and removed through total ear canal ablation. Three months after surgery, osteoma was recurred and broken out of edematous skin lesion. It was considered that an inappropriate surgical removal of the tissue which attached base boarder of the polyp would be cause of the recurrence of the osteoma.

• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.235-239
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• 2018

Due to the structure with one end closed, the external ear resonance effect in which the high frequency is amplified can be generated, and the sound can be perceived well. The external ear resonance normally has a first peak and a second peak. On average, the first peak has a gain of 18.6 dB at 2620 Hz and the second peak has a gain of 18.2 dB at 4210 Hz. The resonance of the external auditory canal changes with the state of the tympanic membrane, the presence of the ventilation tube, and the structure (length, diameter, shape) of the external auditory canal. A patient with a postauricular meatomastoid cutaneous fistula was admitted to the hospital with a foreign body which is the molding of the hearing aid. After removal of the foreign body, the resonance of the external auditory canal was lost and the subjective sound cognitive ability decreased. In the case of postauricular meatomastoid cutaneous fistula, we confirmed the improvement of sound cognitive ability, the change of pure tone hearing threshold, and the change of the external ear resonance after reconstruction of the ear canal without middle ear reconstruction.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.566-574
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• 1999

This study was conducted to examine the outbreak rate and the causative agents of otitis externa in 26 dogs (49 ears ; 23 dogs = bilateral, 3 dogs = unilateral), and the normal microfloras of external ear canal in 68 dogs(133 ears ; 65 dogs = bilateral, 3 dogs = unilateral ) in Taegu, 1997. The breed, living environment, sex, age and season distribution of otitic dogs were as follows : Dogs with erect and hairy ears(42.3%), pendulous and hairy ears(38.5%), indoor(92.3%), female(65.4%) and below one year old(38.5%) were more prevalent. According to season, otitis externa was mainly occurred between July and October. The major causative agents of canine otitis externa were Malassezia pachydermatis (32.7%), Staphylococcus aureus (26.5%) and S intermedius (16.3%). In the microorganism isolated 39 otitic ear canals, single infection was 53.8% and mixed infection was 46.2%. The normal microfloras of canine external ear canal were fungi including M pachydermatis, Aspergillus spp, Microsporum canis, Alternaria spp, Verticillium spp and Yeast, and bacteria including Staphylococcus spp(10 species including S xylosus), Bacillus spp, Corynebacterium spp, Listeria spp, Actinomyces pyogenes and Escherichia coli. No growth was 34.6%.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.2 no.1
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• pp.27-33
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• 2009

Generally, implantable microphone has been implanted in the temporal bone for implantable middle ear hearing devices (IMEHDs). In this case, the microphone's membrane can be damaged and can be generated biological noise. In order to overcome the these problems, the location of implanted microphone should be changed. As an alternative, the microphone can be implanted in the external auditory canal. However, the sound emission can be produced because of vibration transducer toward reverse direction from the tympanic membrane to the external auditory canal. In this paper, an amount of the emitted sound is measured using a probe microphone as the changing the position of microphone in the external auditory canal of a physical ear model, which is similar to acoustical and vibratory properties of the human ear. Through the measured value, the location of the microphone was assumed in the external auditory canal. According to the analysis, the microphone input sound can be decreased when microphone position become more distance from the tympanic membrane in the auditory canal. However, the external auditory canal is not appropriated to implantable microphone position, because sound emission is not completely eliminated.

• Journal of the korean veterinary medical association
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• v.51 no.4
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• pp.204-207
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• 2015