• Asian Pacific Journal of Cancer Prevention
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• 제15권10호
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• pp.4125-4128
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• 2014

The median ages at death from cancers between 1985 and 2005 were calculated to demonstrate that inherent anticancer mechanisms may be a common pathway for different cancers. Seventy-eight patients with gastric, liver and lung cancers, were recruited in the solid cancer group. The leukemia group consisted of 31 patients with three main types of leukemia. The controls were 100 healthy individuals. The samples were typed using an HLA-DR/DQ PCR-SSP typing kit. The results showed that the median ages at death from all causes were 64.7 years in 1985 and 70.1 years in 2005. The range of the median ages at death from all cancers was similar to the corresponding value for deaths attributed to all causes. The frequency of $DRB1^*03$ was 9.6% in the solid cancer group and 3.0% in the control group (p<0.05). The frequency of $DRB1^*04$ in the leukemia group were significantly lower than that of the control (p<0.05). $DRB1^*13$ and $DRB1^*06$ frequencies in the leukemia group were significantly higher than those of the controls (p<0.05). It is suggested that inherent anti-cancer mechanisms may be a common pathway for different cancers and are associated with the immune system and HLA.

• 한국전문물리치료학회지
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• 제11권3호
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• pp.85-90
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• 2004

The purpose of this study was to find the difference in muscle firing rate between each muscle according to the knee angle with the quadriceps femoris which is a representative action muscle of the lower extremity. Seven normal healthy subjects were recruited. The median frequency (MDF) of muscle contraction was recorded from vastus lateralis, vastus medialis, and rectus femoris muscles using the surface EMG, in 5 seconds, during maximal isometric knee extension. The data were analyzed by the two-way repeated ANOVA. The results of the study were as follows: 1) median frequency of muscle contraction was significantly higher at the vastus lateralis, vastus medialis, and rectus femoris in descending order. 2) median frequency of muscle contraction was significantly higher at the $30^{\circ}$, $60^{\circ}$, and $90^{\circ}$ in descending order. Consequently, muscle recruitment at the knee decreases the EMG activity of the lengthened muscle. This study suggests that the change in EMG activity at different muscle lengths resulted in affecting the muscle firing rate during the knee extension.

• 산업경영시스템학회지
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• 제35권2호
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• pp.30-36
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• 2012

This study is aimed to show that an asymmetric load in the frontal plane leads to an increase in low back loading and fatigue in comparison with a symmetric load when workers lift an external weight by investigating previous studies and verifying the phenomenon with an experiment. Ten male subjects are required to lift and hold an given external load at 70cm height during 50sec, then the EMG amplitude and median frequency on bilateral low back muscle groups (Longissimus, Iliocostalis, and Multifidus) are recorded and analyzed. Independent variables are two-level load weight (13kg, 20kg) and three-level LCG (Center, 6.5cm to the right, and 13cm to the right), and dependent variables are EMG amplitude average, difference, and Fatigue Index (FI). Results show that load weight increases significantly amplitude average and FI, but LCG does significantly amplitude difference and FI significantly (P-value < 0.05). Also the correlation coefficient between amplitude difference and FI is over 0.99. These implies that trunk loading should be explained by not EMG amplitude but muscle fatigue aspect since the association between an external load and amplitude is linear, but the relationship between an external load and median frequency as muscle fatigue index is almost exponential.

• Journal of Biosystems Engineering
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• 제36권4호
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• pp.285-289
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• 2011

Muscle fatigue is characterized as a progressive increase in discomfort arising from the active muscle at moderate load levels are maintained. The median frequency is the most commonly used as a parameter to describe muscle fatigue. However, the estimate of the median frequency is difficult to indicate muscle fatigue because of its high standard deviation and instability. This paper investigates the power changes of the appropriate low frequency band as a fatigue parameter in EMG during isotonic exercise. To select the appropriate band, linear regression lines are employed to calculate the slopes and the coefficient of determination. Three females and seven males volunteered to participate in surface EMG recordings placed on the biceps brachii and each recording experiment continued until their exhaustion. The results of experiment shows that the power changes of the selected low frequency band (15~45 Hz) have linear slopes and high determinant coefficients. Therefore, this fatiguing parameter using the power changes of the low frequency band is valid to measure the state of muscular fatigue.

• 대한방사선기술학회지:방사선기술과학
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• 제30권1호
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• pp.1-6
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• 2007

인위적으로 noise factor를 주고 그 위에 촬영을 하여 노이즈와 영상의 복합물을 만들었다. 그 후 Low Pass Filter(LPF)와 Median Filter(MF)의 두 종류의 필터를 통하여 노이즈를 제거하고 노이즈를 나타내는 지표로 Signal To Noise Ratio(SNR), Peak Signal to Noise Ratio(PSNR), Mean Square Error(MSE)를 비교하였다. 또한 Median Filter의 kernel size에 따라서도 노이즈제거효과를 평가하였다. 각각의 처리된 영상과 원 영상을 비교하여 원 영상에 가까운 영상을 찾아봄으로서 어떤 필터가 유용하며 어떤 주파수대를 제거해야 하는가를 알고자 실험하였다. Cutoff frequency가 다른 필터를 비교 했을 때 noise power 값에는 상관없이 cutoff frequency $2/3\pi{\sim}3/4\pi$까지가 원 영상에 가까우면서 SNR, PSNR이 좋다. 따라서 높은 filter 효과를 나타낸다고 할 수 있다. Median filter의 kernel size가 커짐에 따라서 SNR 값이 커지며 반대로 MSE의 값이 작아져 filter 효과는 좋아 짐을 알 수 있다. 의료 영상에 filter를 적용하는 것에 대해서 대부분의 영상들이 filter 적용 후에 왜곡된 상이 되곤 하였다. 의료 영상은 다른 영상과는 달리 공간 분해능을 유지하면서 평활화(노이즈 제거)하는 것이 중요한 문제이다. SNR 등 정량적 지표에 의한 비교와 함께 시각적 평가가 병행되어야 할 필요가 있다.

• 한국산학기술학회논문지
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• 제14권3호
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• pp.1258-1265
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• 2013

본 논문의 목적은 랩탑 컴퓨터의 터치패드 및 두 개의 클릭 버튼 위치에 따른 손목과 어깨 부위 근육의 EMG 진폭 및 중앙 주파수 변화를 알아보는 것이다. 기존 연구결과를 바탕으로 손목과 어깨의 외전현상이 근골격계질환으로 이어지는 메커니즘을 살펴보고, 이를 토대로 연구가설이 설정되었다. 실험에서 터치패드 및 클릭버튼의 위치는 기존의 중앙 아래(bottom center, BC)와 중앙 아래에 위치하지만 $45^{\circ}$ 반시계방향으로 회전된 방식(bottom center with rotation, BCR), 그리고 회전없이 중앙 오른쪽에 위치한 경우(bottom right, BR)가 비교되었다. 10명의 피실험자는 오른 손으로 5분 동안 터치패드 및 두 개의 버튼을 이용하는 task를 각각의 시행하는 동안 EMG 진폭과 중앙 주파수가 측정되었다. 손목 부위의 근육은 척측수근굴근, 어깨부위의 근육은 위쪽 승모근이 선정되었다. 실험결과 손목부위에서는 BC의 경우가 진폭은 크게 나타나고 중앙 주파수는 작게 나타났으며, 어깨부위에서는 BC와 BCR이 BR보다 진폭은 크고 중앙 주파수는 작게 나타났다. 또한, 손목부위에서는 진폭과 중앙 주파수 모두에서 BCR과 BR의 차이가 유의하게 나타나지 않았고, 어깨부위에서는 BC와 BCR에서의 차이가 나타나지 않았다. 이러한 결과는 BC에서는 손목과 어깨의 외전이 동시에 나타나고, BCR은 어깨의 외전만, 그리고 BR은 손목과 어깨에서 외전이 모두 나타나지 않기 때문이다.

• 음성과학
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• 제11권1호
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• pp.55-64
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• 2004

This study was to determine the effects of a massage and oro-facial exercise program on spastic dysarthric patients' lip muscle function using an electromyogram (EMG). Three subjects with Spastic Dysarthria participated in the study. The surface electrodes were positioned on the Levator Labii Superior Muscle (LLSM), Depressor Labii Inferior Muscle (DLIM), and Orbicularis Oris Muscle (OOM). To examine lip muscle function improvement, the EMG signals were analyzed in terms of RMS (Root Mean Square) values and Median Frequency. In addition, the diadochokinetic movements and the rate of sentence reading were measured. The results revealed that the RMS values were decreased and the Median Frequency moved to a high frequency area. Diadochokinesis and sentence reading rates were improved.

• Nutrition Research and Practice
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• 제6권5호
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• pp.444-450
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• 2012

This study was performed to evaluate the validity of the food frequency questionnaire (FFQ), which is being used at the Samsung Medical Center. In total, 305 (190 males and 115 females) participants consented and completed the 3-day diet records and FFQ. Age, gender and energy-adjusted and de-attenuated correlations ranged from 0.317 (polyunsaturated fatty acid) to 0.748 (carbohydrate) with a median value of 0.550. The weighted kappa value ranged from 0.18 (vitamin A) to 0.57 (carbohydrate) with a median value of 0.36. More than 75% of the subjects were classified into the same or adjacent quartiles. The FFQ had reasonably good validity compared with that of another study. Therefore, our FFQ is considered a proper method to assess nutrient intake in healthy Korean adults.

• 대한산업공학회지
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• 제19권4호
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• pp.87-96
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• 1993

Spectrum analysis of surface electromyogram (FMG) signals is an effective approach to the study of localized muscular fatigue during isometric contraction. Many investigators have con firmed the frequency of the EMG signals being lowered during sustained contaction. In this study, the cyclic loading tasks were performed, and a comparison was made for the median power frequency shift pattern of the EMG signals with the sustained contraction of the same load. The median power frequency shift of the EMG signals for the cyclic loading task was found to be a part of that for the sustained contraction. Based on this result, a new muscle fatigue index was computed by normalizing the duration of the sustained contraction. A fatigue index was obtained as a function of exertion level and the work/rest schedule. With the proposed fatigue index, it is possible to evaluate or predict the degree of muscular fatigue for a physically demanding task.

• 대한인간공학회지
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• 제18권1호
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• pp.55-69
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• 1999

It is very common to use the powered hand tools to enhance the productivity in various types of industry. But the use of the powered hand tools could cause health problems such as cumulative trauma disorders and vibration white fingers. In this study. the effects of hand-arm vibration and anatomical hand position on localized muscle fatigue were analyzed. Eight healthy male subjects volunteered for the study. Vibration frequencies of 0, 40, 80, 100, 150, and 200Hz and hand position of flexion and ulnar deviation were selected for the independent variables of the experiment. Median frequency shifting was used as a dependent variable. The results indicated that at the vibration frequency of 40Hz and accelation of 2g, the muscle fatigue was the greatest. For the hand position. there was significant difference between neutral and flexion. and neutral and ulnar deviation, but no difference between flexion and ulnar deviation. These results could be applied in designing powered hand tools to minimize the health problems.