• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.22-27
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• 2001

Cochlea is well known to have the ability to analyze a wide frequency and this ability seems to be caused to the Basilar Membrane(BM) configuration. However, the relationship between the Cochlea frequency-position map is not clear. In this paper, the three-dimensional BM Model was made using the Finite Element method. Then, an attempt was made to examine the influence of the BM configuration on the Cochlea frequency-position map. Theoretical consideration reveals that the wide frequency-position of Cochlea is achieved by not only the BM configuration change along the length of the Cochlea but also the change of the Young's module of the BM along the length of the Cochlea.

• 한국공작기계학회논문집
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• 제11권1호
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• pp.114-119
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• 2002

Cochlea is well known to have the ability to analyze a wide frequency and this ability seems to be caused to the Basilar Membrane(BM) configuration. However, the relationship between the Cochlea frequency-position map is not clear. In this paper, the three-dimensional BM Model was made using the Finite Element Method. Then an attempt was made to examine the influence of the BM configuration on the Cochlea frequency-position map. Theoretical consideration reveals that the wide frequency-position of Cochlea is achieved by not only the BM configuration change along the length of the Coohlea but also the change of the Young's module of the BM along the length of the Cochlea.

• 대한의용생체공학회:의공학회지
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• 제16권1호
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• pp.77-84
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• 1995

Nl and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. Nl -N2 audiograms were made by means of regulating stimulant intensities in order to produce constant Nl -N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip 15 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both nonlinear and active functions of the Cochlea can be monitored by Nl -N2 audiograms. Key words : Guinea Pig, Cochlea, Wl and N2 Gross Neural Action Potential, Nl -N2 audiogram.

• 대한의용생체공학회:의공학회지
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• 제16권4호
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• pp.471-480
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• 1995

기니픽 고막에의 격음 노출 전후에 N1-N2 오디오그램의 변화를 검사하였다. 격음 노출은 106 dB SPL의 세기와 10KHz의 주파수를 가진 연속 격음을 10분 동안 노출시키는 방법이였다. 격음 노출 전후의 N1-N2 오디오그램들을 비교한 결과, 격음 노출된 달팽이관이 그의 기능을 영구적으로 상실하고 있음을 보여줬다. 가장 두드러진 한계치의 이동이 12-13.2KHz 사이에서 발생하였다. 격음 노출후의 달팽이관 기능의 변화는 격음 손상 이전의 달팽이관 상태에 따라 달라졌다. 좀 더 예민한 달팽이관이 덜 예민한 달팽이관 보다 격음 손상이후 그 기능면에서 더욱 심각하게 손상되었다.

• The Journal of the Acoustical Society of Korea
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• 제24권1E호
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• pp.1-6
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• 2005

The inner hair cell stereocilia of the guinea pig cochlea was examined under a scanning electron microscope (SEM) after loud tone exposure onto the ear drum of the animal. Before and after guinea pigs were exposed to intensive and continuous tone such as 106 dB SPL in intensity, the functioning of the cochlea was monitored by N1-N2 audiograms. The structural damage of the stereocilia of inner hair cells (IHCs) and outer hair cells (OHCs) was examined using the SEM in x 1500 magnification. The comparison between the functional change of the cochlea and the structural damage of the IHC stereocilia is done by means of photographic observation. It can be shown that the functional change might be related to the structural damage of the IHC stereocilia after intensive acoustic trauma.

• 대한의용생체공학회:의공학회지
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• 제25권3호
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• pp.207-215
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• 2004

본 연구에서는 유전 프로그램을 이용하여 6가지 형태의 금속 와이어 배치를 가진 전극을 생성하여 각 전극이 3차원 형태의 달팽이관에 미치는 기계적인 영향과 그 거동을 유한요소법을 이용하여 분석하였다. 그리고 전극이 삽입되는 달팽이관은 helico-spiral 근사방법에 의해 결정된 식을 이용하였으며, 고실계단(scala tympani)의 형태는 실제 고실계단 단면의 영상정보를 추출하여 얻어내었다. 해석결과 금속 와이어가 평행하게 배치될 경우 가장 큰 힘을 달팽이관 외벽에 전달하며, 삽입에도 가장 큰 힘이 필요한 것을 알 수 있었다. 그리고 달팽이관은 3차원 구조이므로 전극이 삽입되면서 삽입 전에 자극 사이트가 바라보도록 설정한 방향보다 조금 돌아감을 확인하였다. 이 연구의 결과로부터 전극의 강성이 외상(trauma)을 줄이는데 중요하다는 것을 알 수 있다.

• BMB Reports
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• 제50권10호
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• pp.487-495
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• 2017

Mammalian inner ear comprises of six sensory organs; cochlea, utricle, saccule, and three semicircular canals. The cochlea contains sensory epithelium known as the organ of Corti which senses sound through mechanosensory hair cells. Mammalian inner ear undergoes series of morphogenesis during development beginning thickening of ectoderm nearby hindbrain. These events require tight regulation of multiple signaling cascades including FGF, Wnt, Notch and Bmp signaling. In this review, we will discuss the role of newly emerging signaling, FGF signaling, for its roles required for cochlear development.

• 대한의용생체공학회:의공학회지
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• 제11권1호
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• pp.83-88
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• 1990

A New speech processing algorithm using neural networks is proposed. We transform input data into frequency domain and process them by neural networks of 22 output neurons which have Bark scale on the ground that the Bark scale is similiar with that of the characteristics of human cochlea. An utilized neural network is multilayer perceptron, and the characteristics of cochlea have it trained by error back propagation learning algorithm. The trained neural networks suffices functions of human cochlea including the effects of automatic gain control, compression and equalization. Simulation results show that the proposed speech processing algorithm has good performance in automatic gain control, compression and equalization.

• 재활복지공학회논문지
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• 제5권1호
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• pp.41-46
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• 2011

감각신경성 난청의 원인 중 하나는 내이에 존재하는 와우(cochlea)의 기능적 이상 때문이다. 와우에서 내유모세포(inner hair cell, IHC)나 신경의 기능적 이상이 있는 곳을 'dead region'이라고 한다. 보청기에서 dead region에 속하는 주파수 영역의 증폭은 효과가 미약한 것으로 알려져 있다. 본 논문에서는 dead region의 위치에 따른 음성신호의 인지 능력 비교와 dead region이 존재할 때 보청기의 효과적인 이득값을 알아보기 위해 WRS 검사와 선호도 조사를 실시하였다. WRS(Word Recognition Score)검사와 선호도 조사를 위해 정상 청력 능력을 지닌 성인 남녀 8명을 대상으로, white noise와 babble noise를 이용하여 신호 대 잡음비(SNR) 0dB의 조건으로 검사음과 혼합하였으며, dead region의 영역을 세 가지로 분류하였다. 주파수 영역에 따라 low-frequency, mid-frequency, high-frequency dead region으로 나누고, 각 dead region에 따라 14.5 dB, 11.5 dB, 6 dB의 증폭 이득을 다르게 하여 결과를 비교하였다. dead region의 위치에 따른 검사 결과는 각 영역별로 차이가 있었다. WRS 검사결과 low-frequency dead region일 때 보다, mid-frequency dead region나 high-frequency dead region일 때의 WRS점수와 선호도 평가가 높게 나왔으며, 증폭 이득값의 차이를 비교해 보았을 때, 14.5 dB의 이득에 비해 낮은 이득을 주었을 때 WRS 검사 결과값이 더 높게 나왔으며, 높은 이득일수록 선호도 조사에서 낮은 점수를 받았다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권10호
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• pp.5631-5635
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• 2013

Cochlea hair cell death is regarded to be responsible for the radiation-induced sensorineural hearing loss (SNHL), which is one of the principal complications of radiotherapy (RT) for head and neck cancers. In this mini-review, we focus on the current progresses trying to unravel mechanisms of radiation-induced hair cell death and find out possible protection. P53, reactive oxygen species (ROS) and c-Jun N-terminal kinase (JNK) pathways have been proposed as pivotal in the processes leading to radiation hair cell death. Potential protectants, such as amifostine, N-acetylcysteine (NAC) and epicatechin (EC), are claimed to be effective at reducing radiation-inducedhair cell death. The RT dosage, selection and application of concurrent chemotherapy should be pre-examined in order to minimize the damage to cochlea hair cells.