• Journal of Sensor Science and Technology
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• v.13 no.6
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• pp.479-487
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• 2004

The prevention of noise induced hearing loss is very important, because there is no treatment for it. There are some kinds of devices for hearing protection, and those are effective in preventing a noise induced hearing loss. However, people often resist the use of hearing protection devices because it is difficult to have a conversation. Therefore, a hearing protection device is must effective not only in hearing protection but also in preserving communication ability. In this paper, we proposed a small acoustic filter for ITE type noise protector to solving the problem about the difficulties of conversation. That is applied a principle of acoustic filters that have been used for a muffler of automobiles, guns, and etc. To find out the sound transmission characteristic at the eardrum, we regarded an acoustic filter and external ear canal as a coupled system. So, we simulated the coupled system with OrCad, and experimented with a designed acoustic filter and a 2 cc coupler which has the same transmission characteristic as the external ear canal has. We confirmed that it is possible to adjustment acoustic transmission characteristics through simulation of electrical model for acoustic filter and external ear and experiments using designed small acoustic filters.

• Journal of Veterinary Clinics
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• v.27 no.5
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• pp.622-625
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• 2010

Inflammatory polyps in feline ear are nonneoplastic, inflammatory growths that arise from the middle ear or the eustachian tube and extended into the pharynx or external ear canal. Two 2-year-old female Russian blue cats showed 2-3 weeks history of aural discharge, crust formation in external ear, and head or ear shaking. Two masses were surgically excised from ear canal, and submitted for diagnosis. Histopathologically, these masses were covered with hyperplastic ciliated epithelium or nonkeratinizing squamous epithelium with partial erosion and ulceration. The core of masses was consisted of proliferated connective tissue and massive infiltration of mononuclear cells. Immunohistochemically, about 90% of infiltrated mononuclear cells demonstrated CD3 positive T cell. According to both polymerase chain reaction (PCR) and reverse transcriptase-PCR, tissues samples were negative for feline viral pathogens. Based on the clinical, gross, histopathologic findings, these two cases were diagnosed as inflammatory polyps originated from the middle ear in cats.

• Korean Journal of Bronchoesophagology
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• v.8 no.2
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• pp.51-55
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• 2002

Angiolymphoid hyperplasia with eosinophilia(ALHE) is an uncommon idiopathic condition that presents with isolatedor grouped cutaneous plaques or nodules of the head and neck. Extracutaneous involvement is rare. ALHE is a distinct pathologic entity marked by a proliferation of blood vessels with distinctive large endothelial cells accompanied by a characteristic inflammatory infiltrate that includes eosinophils. The lesion is benign but may be persistent and difficult to eradicate. The authors have recently experiecned a case of angiolymphoid hyperplasia with eosinophilia in a 52-year-old male who had a painless enlarging mass in his right preauricular area and external ear canal for several years. We present this case with the review of literatures.

• Journal of Biomedical Engineering Research
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• v.41 no.1
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• pp.22-27
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• 2020

Auditory stimuli are commonly used in various electroencephalogram experiments, also in EEG-based brain-computer interface systems. However, using conventional earphones that blocks the ear canal attenuates or even blocks external environmental sound which might cause loss of crucial information from surroundings. Instead, bone-conductive earphones are able to deliver sound through vibration without blocking the ear canal. To investigate the feasibility of the bone-conductive earphones for auditory-stimuli based experiments, we compared N100 event-related potential features as well the event-related spectral perturbation and inter-trial coherence of auditory steady-state response between conventional and bone-conductive earphones. The results showed no significant differences between bone conduction and conventional earphones regardless of distinct sound pressures. This result shows that bone conductive earphones can be used for auditory experiments when the environmental sound is crucial to the user.

• 대한두경부종양학회:학술대회논문집
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• 2007.11a
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• pp.215-215
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• 2007

• Radiation Oncology Journal
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• v.27 no.4
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• pp.173-180
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• 2009

Purpose: To investigate the role of radiotherapy for squamous cell carcinomas of the external auditory canal and middle ear. Materials and Methods: A series of 35 patients who were treated at a single institution from 1981 through 2007 were retrospectively analyzed. Thirteen patients were treated by radiotherapy alone; four by surgery only and 18 by a combination of surgery and radiotherapy. The total radiation dose ranged from 39~70 Gy (median, 66 Gy) in 13~35 fractions for radiotherapy alone and 44~70 Gy (median, 61.2 Gy) in 22~37 fractions for the combined therapy. Clinical end-points were the cause of specific survival (CSS) and local relapse-free survival (LRFS). The median follow-up time was 2.8 years (range, 0.2~14.6 years). Results: The 3-year CSS and LRFS rate was 80% and 63%, respectively. Based on a univariate analysis, performance status and residual disease after treatment had a significant impact on CSS; performance status and histologic grade for LRFS. Patients treated by radiotherapy alone had more residual disease following the course of treatment compared to patients treated with the combined therapy; 69% vs. 28%, respectively. Conclusion: Our results suggest that radiation alone was not an inferior treatment modality for CSS compared to the combined therapy for squamous cell carcinoma of the external auditory canal and middle ear. However, local failure after radiotherapy is the main issue that will require further improvement to gain optimal local control.

• Clinical and Experimental Otorhinolaryngology
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• v.11 no.4
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• pp.259-266
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• 2018

Objectives. Carcinomas of the external auditory canal (EAC) are rare, and management remains challenging. Previous studies seeking prognostic factors for EAC cancers included cancers other than carcinomas. In this study, we analyzed the treatment outcomes of, prognostic factors for, and survival rates associated with specifically squamous cell carcinoma (SCC) of the EAC. Methods. A retrospective review of 26 consecutive patients diagnosed with SCCs of the EAC in a 10-year period was performed in terms of clinical presentation, stage, choice of surgical procedure, and adjunct therapy. Overall survival (OS) and recurrence-free survival (RFS) were calculated and univariate analysis of prognostic factors was performed. Results. The median age of the 26 patients with SCCs of the EAC was 63 years (range, 40 to 72 years), and 16 males and 10 females were included. According to the modified University of Pittsburgh staging system, the T stages were T1 in 11, T2 in six, T3 in four, and T4 in five cases. The surgical procedures employed were wide excision in three cases, lateral temporal bone resection (LTBR) in 17, and extended LTBR in four, and subtotal temporal bone resection in two. Two patients underwent neoadjuvant chemotherapy, and two underwent adjuvant chemotherapy. One patient received preoperative radiation therapy, and eleven received postoperative radiation therapy. Of the possibly prognostic factors examined, advanced preoperative T stage and advanced overall stage were significant predictors of RFS, but not of OS. Conclusion. The advanced T stage and overall stage were associated with decreased survival after surgical treatment in patients with SCC of the EAC, highlighting the importance of clinical vigilance and early detection.

• Archives of Plastic Surgery
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• v.46 no.6
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• pp.525-534
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• 2019

Background In microtia patients with bilateral hearing impairment, hearing improvement is crucial for language development and performance. External auditory canal reconstruction (EACR) has been performed to improve hearing, but often results in complications. We performed transcutaneous bone conduction implant (TBCI) surgery in these patients. This study aimed to evaluate the safety and efficacy of TBCI surgery. Methods A retrospective review was performed of five patients who underwent auricular reconstruction and TBCI surgery and 12 patients who underwent EACR between March 2007 and August 2018. Hearing improvement was measured based on the air-bone gap values using pure-tone audiometry over a 6-week postoperative period. We reviewed other studies on hearing improvement using EACR and compared the findings with our results. The surgical techniques for TBCI were reviewed through case analyses. Results Postoperative hearing outcomes showed a significant improvement, with a mean gain of 34.1 dB in the TBCI cohort and 14.1 dB in the EACR cohort. Both gains were statistically significant; however, the TBCI cohort showed much larger gains. Only three of the 12 patients who underwent EACR achieved hearing gains of more than 20 dB, which is consistent with previous studies. All patients who underwent TBCI surgery demonstrated hearing gains of more than 20 dB and experienced no device-related complications. Conclusions TBCI is a safe and effective method of promoting hearing gains in microtia patients with bilateral hearing impairment. TBCI surgery provided better hearing outcomes than EACR and could be performed along with various auricular reconstruction techniques using virgin mastoid skin.

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.263-266
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• 1998

외이도의 직경 및 길이와 외이도 질환과의 연관성을 알아보고자 73두 성견을 실 험에 이웅하였다. 임상중상, 배양 및 도말 검사를 통하여 외이 질환이 얼는 정상군 57개의 이 관과, 질환이 있는 비정상군 89개의 이관에 직경과 길이를 평가하기 위한 간접적인 방법으로 이관내 조영술을 실시하였다. 비정상군은 정상군에 비하여 윤상연골 및 귓바퀴 연골의 직경 이 더 넓었다. 수직외이도를 구성하는 귓바퀴 연골의 길이는 비정상군4(12.79{\pm} 3.08)이 정상 군(12.79{\pm}5.87 mm)$에서 보다 유의성 있게 길게 나타났다(p<0.001). 심한 외이도 협착증을 보이는 21개의 귀에서는 외이도 질환을 발견할 수 없었으며, 외이도 질환이 심한 귀에 있어 서 그 직경과 길이가 정상군에 비하여 넝고 길게 나타났다(p<0.05). 본 실험의 결과로 보아 외이도관의 협착증과 외이도 질환과는 연관성이 발견되지 않았으나, 환기와 귀내 분비물의 배출을 방해하는 긴 수직외이도를 갖는 귀가 외이도 질환과 밀접한 관계가 있는 것으로 생각 되었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.39.1-39.6
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• 2015

Skull-base osteomyelitis is a rare disease affecting the medulla of the temporal, sphenoid, and occipital bones. In general, it occurs due to external ear canal infections caused by malignant external otitis. Skull-base osteomyelitis usually affects elderly diabetic patients. The patient, a 58-year-old man, was referred for evaluation and management of the left jaw. Clinical examination of the patient revealed pain in the left jaw and mouth-opening deflection to the left. The maximum active mouth opening was measured to about 27 mm. Panoramic, CT, and CBCT revealed bone resorption patterns in the left condyle. Through control of diabetes, continued pharmacological treatment, arthrocentesis, and occlusal stabilization appliance therapy were carried out. The extent of active mouth opening was increased to 45 mm, and pain in the left jaw joint was alleviated. This was a case wherein complications caused by failure to control diabetes induced skull-base osteomyelitis. There is a need for continued discussion about the advantages and disadvantages of arthrocentesis with lavage for patients with skull-base osteomyelitis and other treatment options.