• 대한의용생체공학회:의공학회지
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• 제39권5호
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• pp.183-187
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• 2018

In this paper, we investigated the efficiency according to the output transmission method of the round window driving type AMEIs (active middle ear implants) through the cadaveric experiment. For the experiment, we fabricated DRT (direct rod transducer) and FMT (floating mass transducer) type vibrational transducers based on our previous studies and conducted their output characteristics were measured. TCBT (tri-coil bellows transducer) and DFMT (differential floating mass transducer) were implemented with the same driving force and electrical characteristics as one of DRT and FMT, respectively. In the experiment using three human temporal bone, normal stapes vibration was measured with 1 Pa in front of tympanic membrane, and then was compared with each output of transducers. From the comparison, the DRT type vibration transducer was superior in overall energy transfer efficiency, especially in the low frequency range. There was no difference in implantation difficulty between the two transducers. The results of this study suggest that the DRT type vibrational transducer is more efficient and needs further study to overcome the low frequency degradation in round window approaching with FMT.

• Journal of Korean Neurosurgical Society
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• 제63권5호
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• pp.640-648
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• 2020

Objective : This study aimed to assess the relationship between increased intracranial pressure (ICP) and mastoid effusions (ME). Methods : Between January 2015 and October 2018, patients who underwent intracranial surgery and had ICP monitoring catheters placed were enrolled. ICP was recorded hourly for at least 3 days. ME was determined by the emergence of opacification in mastoid air cells on follow-up brain imaging. C-reactive protein (CRP) levels, presence of endotracheal tube (ETT) and nasogastric tube (NGT), duration of intensive care unit (ICU) stay, duration of mechanical ventilator application, diagnosis, surgical modalities, and presence of sinusitis were recorded. Each factor's effect on the occurrence of ME was analyzed by binary logistic regression analyses. To analyze the independent effects of ICP as a predictor of ME a multivariable logistic regression analysis was performed. Results : Total of 61 (53%) out of 115 patients had ME. Among the patients who had unilateral brain lesions, 94% of subject (43/50) revealed the ipsilateral development of ME. ME developed at a mean of 11.1±6.2 days. The variables including mean ICP, peak ICP, age, trauma, CRP, ICU stays, application of mechanical ventilators and presence of ETT and NGT showed statistically significant difference between ME groups and non-ME groups in univariate analysis. Sex and the occurrence of sinusitis did not differ between two groups. Adding the ICP variables significantly improved the prediction of ME in multivariable logistic regression analysis. Conclusion : While multiple factors affect ME, this study demonstrates that ICP and ME are probably related. Further studies are needed to determine the mechanistic relationship between ICP and middle ear pressure.

• 재활복지공학회논문지
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• 제5권1호
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• pp.59-64
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• 2011

인공 중이 (IMEHD, implantable middle ear hearing device)용 플로팅 매스 트랜스듀서는 제작 과정상에서 발생하는 구조적 오차 및 제작 결합시의 문제점들로 인해 설계 시 의도와 다른 진동 특성을 가질 수 있게 되고, 이렇게 제작된 진동 트랜스듀서는 향후 실제 환자에게 이식되었을 때의 진동체 진동 성능을 예측하기 어려운 문제점이 있다. 본 연구에서는 제작된 플로팅 매스형 트랜스듀서에 대해 설계값과의 비교 평가 및 향후 컴퓨터 모델화된 청각 중이 집중 소자 모델에 적용이 가능하도록 기 제작된 진동체의 집중 소자 모델 파라미터들을 추정할 수 있는 방법을 제안하였으며, 제안된 방법을 LabVIEW 기반의 그래픽 유저 인터페이스 소프트웨어로 구현하였다. 제안된 방법은 실제 제작된 플로팅 매스형 진동체의 진동 변위 및 위상 데이터를 이용하여 해당 진동체의 집중 모델 파라미터들을 순차적 이차 프로그래밍 (SQP, sequential quadratic programming) 방법으로 추정하는 방식이다. 구현된 방법을 이용하여 측정 데이터에 가해지는 잡음의 양에 따른 플로팅 매스형 진동 트랜스듀서의 집중 모델 파라미터 추정 시의 발생 오차 변화를 컴퓨터 시뮬레이션을 통해 조사하여 본 방법의 파라미터 추정 정확도를 확인하였다. 또한, 실제로 제작한 인공중이용 진동 트랜스듀서에 대해 측정된 진동 변위 및 위상 데이터를 이용하여 진동체의 집중 모델 파라미터들을 추정하였으며, 기존 설계값들과 비교를 통해 제안된 방법의 유용성을 평가하였다.

• 대한의용생체공학회:의공학회지
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• 제26권3호
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• pp.139-144
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• 2005

An implantable microphone that can be utilized as part of a totally implantable hearing aid is designed and implemented. The proposed microphone is implanted in the center of the pinna, and designed to ensure the speech frequency range and the appropriate sensitivity. The characteristics of the proposed microphone are evaluated using a finite element analysis (FEA). The microphone is composed of a small electric condenser microphone, titanium case 6.2mm in diameter and 3mm high, and $10{\mu}m$ SUS316L vibrating membrane in contact with hypodermic tissue to maintain the sensitivity of the microphone. The microphone components are all made of biocompatible materials, then the assembled microphone is hermetically sealed using a polymer and ceramic. Experiments with the fabricated microphone confirm an operational bandwidth of up to 5kHz without any decline of sensitivity in 6mm of hypodermic tissue.

• 센서학회지
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• 제22권2호
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• pp.150-155
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• 2013

Recently, various hearing aids are developed to overcome hearing loss. There are available hearing aids, such as air conduction hearing aid, implantable middle ear hearing aid and so on. But air conduction hearing aid is inconvenience caused by howling, and ossicle chain driving type implantable middle ear hearing aid has some week point due to problem of possible nercobiosis of coupling spot along incus long process. In recent years, in order to improve these shortcomings round window (RW) driving hearing aid has been paying attention. In this paper, the physical cochlear model is proposed for a performance evaluation of the RW driving hearing aids of a transducer. In order to verify an experiment proposed on a performance of physical cochlear model, the transducer which has ossicles characteristics is used. By measuring and comparing the frequency characteristics of transducer with ossicles and human temporal bone, performance of physical cochlear model was verified. As from the result of experiment, it is expected that an implemented cochlear model is useful for evaluating characteristics of RW transducer.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1972년도 춘계종합 학술대회 초록집
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• pp.1.2-1
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• 1972

만성중이염의 원인균에 대해서는 여러가지 방면으로 고찰되어 왔다. 저자들은 시대에 따르는 원인균의 분포와 아울러 새로운 항생제제의 개발에 따르는 내성 및 감수성의 정도와 변화 등을 고찰하기 위하여 임의로 선택된 중이염환자의 이루에서 채취된 세균에 대해 이를 분류하고 각종 항생제에 대한 감수성을 검사하였기에 보고한다. 65이에서 분류된 65균주에 대해 Ampicillin Chloramphenicol, Erythromysin, Kanamycin, Gentamycin, Orbenin, penicillin, Streptomycin, Terramyin 및 Colimycin등 10종류의 항생제제에 대한 감수성 청사를 하였다. Gram-negative 군인 pseudomonas(12례, 18.5%)에서는 Colimycin에 91.7% 및 Gentamycin에는 75%의 순으로 감수성이 높았고 proteus (11례 16.9%)에 가장 감수성이 높은 약제는 Ampicillin 81.8%이고 Genta-mycin에 81.8% 등이었다. Gram-positive인 Staphyloccus aureus(19례 29.2%)에서는 Erythromyin에 100% Orbenin에 94.7%의 순으로 감수성이 높았다.

• 센서학회지
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• 제19권6호
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• pp.449-455
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• 2010

Implantable middle ear hearing devices(IMEHDs) have being actively studied to overcome the problems of conventional hearing aids. Vibration transducer, an output devices of IMEHDs, is attached on the ossicular chain and transmits mechanical vibration to cochlea. This approach allows us to hear more clear sound because mechanical vibration is effective to transfer high frequency acoustics, but occurs some problems such as fatigue accumulation to ossicular chian and reduction of vibration displacement caused by mass loading effect. Recently, many studies for the round window stimulation are announced, because it does not cause such problems. It have been studied by older transducers designed for attaching on ossicular chain. In this paper, we proposed a new electromagnetic transducer which consists of two magnets, three coils and a vibration membrane. The magnet assembly, magnet coupled in opposite direction, were placed in the center of three coils, and the optimum length of each coil generating maximum vibrational force was calculated by finite element analysis(FEA). The transducer was implemented as the calculated length of each coil, and measured vibration displacement. From the results, it is verified the vibration displacement can be improved by optimizing the length of coils.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1976년도 제10차 학술대회연제 순서 및 초록
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• pp.85.2-85
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• 1976

Harford는 구씨관기능의 측정에 impedance audiometry의 진단학적 가치를 설명한 바 있다. 고막에 천공이 없는 경우 중이강내의 과도한 음압은 tympanogram에 의해 간접적으로 구씨관기능부전을 나타내는 것은 주지의 사실이다. 구씨관기능이 정상인 경우 valsalva maneuver에 의해 고막은 외측으로 밀려나갈 것이며 이것은 balance meter needle의 운동을 야기시킬 것이다. 이에 저자들은 고막, 중이, 구씨관기능이 모두 정상소견을 보이는 사람을 대상으로 valsalva maneuver에 의해 야기될 수 있는 balance meter needle의 운동거리를 측정함으로써 정상인에서의 구씨관에 의한 중이강의 공기체적의 변동양을 조사하였다. 즉, electroacoustic bridge (Madsen ZO 70) with silicone rubber probe tip을 사용하여 고막, 중이, 구씨관기능이 모두 정상인 사람에서 valsalva maneuver에 의한 balance meter needle의 운동범위는 1.0~4.0(평균치 $1.6{\pm}0.06$)이었으며, 그 치가 1.0미만인 경우에는 어떤 정도의 구씨관기능의 저하 내지 부전을 진단할 수 있는 것으로 생각되어 impedance audiometry에 의한 구씨관기능검사의 의의를 고찰하며 보고하는 바이다

• Applied Microscopy
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• 제12권1호
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• pp.1-10
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• 1982

Serous otitis media is closely related with auditory tube function, but its etiology and pathogenesis are not clearly defined yet. So we tried to prove the theory of hydrops ex vacuo via the experimental study with cats by means of obstructing the pharyngeal orfice of the auditory tube and observe the serial changes in tympanic mucosa through light and electron microscopy. The results are as follows; 1. We confirmed the production of serous otitis media with auditory tube obstruction and have a new understanding of auditory tube function in middle ear aeration. 2. The effusion in serous otitis media was produced from the next day of experiment and increased till the fourteenth day, but decreased after the spontaneous perforation of ear drum. 3. Through the light microscopy, we observed the increasement of the sercretory cells including goblet cells, epithelial hyperplasia, capillary proliferation and invasion of inflammatory cells. 4. Through the elctron microscopy, we observed the protrusion of secretory cells, blobs in cilia, loss of cilia, increasement of vesicles, vacuoles and dense bodies in ciliated cells and Invasion of inflammatory cells. With above results, we concluded that aeration through auditory tube is the most important factor in serous otitis media and presumed the effusion was secreted by secretory cells.

• 동서간호학연구지
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• 제26권1호
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• pp.17-27
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• 2020

Purpose: This study aimed to examine the effect of auricular acupressure therapy on reducing the ocular symptoms and signs for dry eye syndrome. Methods: The participants who were aged ≥ 40 years old and met the inclusion criteria of the ocular surface disease index score ≥ 13 and a tear film break-up time ≤ 10 seconds were enrolled into the two groups: experimental group (n=29) and control group (n=27). Experimental group received auricular acupressure therapy for 8 weeks. Seed stickers were applied to the eye, liver and tubercle point of each ear once a week. Data were collected at pre and 4 and 8 weeks after the treatment and analysed the efficacy of intervention by repeated measures ANOVA. Results: There were significant differences in the ocular surface disease index, standard patient evaluation of eye dryness and a tear film break-up time in both eyes at 8 weeks after the treatment between the two groups. Conclusion: The findings indicate that the auricular acupressure therapy may be helpful for relieving symptoms of dry eye as a nursing intervention. In addition, it could also be utilized as a self-care practice using proper education and training.