• 센서학회지
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• 제25권1호
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• pp.20-26
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• 2016

The bioelectrical impedance (BI) for the young and the elderly was measured using bioelectrical impedance spectroscopy (BIS). First, while applying a current of $600{\mu}A$ to the foot and hand, BI was measured at 50 frequencies ranging from 5 to 1000 kHz. The BI for young subjects was considerably lower than that for old subjects since young subjects have more lean mass (hydration). The prediction marker was 0.74 for young subjects and 0.78 for old subjects. Second, a Cole-Cole diagram was obtained for young subjects and old subjects, indicating the different characteristic frequencies. At 50 kHz, the average phase angle was $7.8^{\circ}$ for young subjects whereas that was $6.1^{\circ}$ for old subjects. Third, BIVA was analyzed for young subjects and old subjects. The vector length was 210.89 [${\Omega}/m$] for young subjects and 326.12 [${\Omega}/m$] for old subjects. At 50 kHz, the resistance (R/H) and the reactance ($X_C/H$) divided by height were 208.94 [${\Omega}/m$] and 28.68 [${\Omega}/m$] for young subject, and 324.33 [${\Omega}/m$] and 34.09 [${\Omega}/m$] for old subjects.

• 대한의용생체공학회:의공학회지
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• 제23권5호
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• pp.413-418
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• 2002

본 연구에서는 변기에 앉아 있을 때 체성분을 효과적으로 측정할 수 있는 체임피던스 측정기(Bioelectrical Impedance Analyzer, BIA)를 개발하고, 이 시스템으로 정확한 체성분 값을 구할 수 있는 방정식을 도출하였다. 이를 위해 설계한 하드웨어고 건강한 한국인 남·여 181명의 체임피던스 값을 변기에 적합한 전극 부착 위치(손목, 허벅지)에서 획득였다. 같은 피험자를 대상으로 기존의 한국인에게 적용시 정확도의 문제를 내포하는 수중체중법의 Siri 방정식을 modified-Siri 방정식으로 적용함으로서 한국인의 제지방량 표준값을 산출하였다. 이 표준값을 기준으로 임피던스 지수, 체중, 성별로 한국인의 제지방을 예측하는 추정식을 얻었다. 제지방량의 추정값과 표준값 사이의 상관계수(r)는 0.977로 높은 관련성을 나타냈으며, SEE(Standard Error of Estimation)은 2.47kg으로 낮은 오차를 나타냈다(p<0.05). 이는 기존의 전극 부착위치인 손목과 발목을 같은 피험자에 적용하여 체임피던스에 의한 제지방량 추정식을 세울 때, 추정값과 표준값 사이의 상관계수(r = 0.978) 및 SEE(2.43kg)와 큰 차이가 없는 것으로 나타났다. 또한. 이중교차검증(Double Cross Validation)을 통해 실험에 참가하지 않은 피검자에 대한 적용 가능성도 유효한 것으로 나타나 본 논문에서 설계한 체임피던스 분석기와 추정식은 한국인의 제지방량을 산출하는데 적합한 것으로 평가되었다.

• 동아시아식생활학회지
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• 제9권2호
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• pp.115-124
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• 1999

The purpose of this study was to investigate the prevalence of obesity in urban and rural junior high school students. Height, weight, skinfold thickness and bioelectrical impedance were measured. The results obtained were summarized as follows : The average height and weight of boys were respectively 159.61cm 50.56kg and those of girls were respectively 155.88cm, 48.12kg. The percentage of obesity was respectively 6.20%, 10.22%, 5.47%, 17.15%, 14.60% for boys and 4.38%. 9.69%, 3.13%, 3.75%, 7.19% for girls by BMI, RI. OI, % body fat I, % body fat II. The rates of obesity were higher in boys than in girls, so nutritional education on obesity for boys is especially necessary. 21.09% of boys and 7.04% of girls in urban and 7.09% of boys and 7.48% of girls in rural were obese. Correlation coefficients between TC(triceps skinfold thickness + calf skinfold thickness) and BMI, RI, OI, % body fat I and % body fat II were 0.66, 0.67, 0.67, 0.77, 0.70.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.331-333
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• 2004

In this study, we implement the multiple frequency bioelectrical impedance analysis system for body composition analysis. Overall system consists of : 1) conductivity electrodes to contact with hands and foots, 2) multiple frequency alternating current signal generator for generating 5, 50, 250kHz frequency and 800uA contained alternating current signal, 3) voltage signal detector, 4) phase signal detector, 5) key-pad to input individual information, 6) micro controller for data processing, 7) LCD for processed data to display, 8) system power, We explain the architecture of the system and required theory to implement the system. Finally, experimental results are illustrated to show the performance of the system.

• Korean Journal of Acupuncture
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• 제29권1호
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• pp.71-81
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• 2012

Objectives : The purpose of this paper was to suggest new diagnostic method that was to supersede the estimation of electrical properties at acupoints. Thus, we developed the multi- frequencies bioelectrical impedance measurement system so as to analyze the state of bio-ions in body fluid as body compositions, not skin impedance at acupoint. Methods : At low frequency, the current does not penetrate the cell membrane and at high frequency, the current passes through both intracellular and extracellular fluid because of the decreas of cell membrane impedance. To confirm the reflection of composition in extracellular fluid or intracellular fluid of segment such as acupoint, the system was developed to detect the acupoint potential between adjacent two points in the area of LU3, LU4 and LU9 using 5,50 and 200KHz. Results : The detected acupoint potential has been decreased according to elevation of frequency. As a result of correlation of left/right identical acupoint, we observed a high correlation of three types of acupoint potential at multi-frequencies. Moreover, we observed the low correlation at 5KHz, and that was a significant factor to be considered as unbalanced relationship of identical acupoints. Conclusions : On the basis of meridian theoretical point of view, we may infer the acupoint's physiological composition using the multi-frequencies bioelectrical impedance measurement system.

• Journal of Gastric Cancer
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• 제19권3호
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• pp.278-289
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• 2019

Purpose: Phase angle obtained using bioelectrical impedance analysis (BIA) provides a relatively precise assessment of the nutritional status of elderly patients. This study aimed to evaluate the significance of phase angle as a risk factor for complications after gastrectomy in elderly patients. Materials and Methods: We evaluated 210 elderly patients (aged ${\geq}65years$) who had undergone gastrectomy for gastric cancer between August 2016 and August 2017. The phase angle cutoff value was calculated using receiver operating characteristic curve analysis according to sex. A retrospective analysis regarding the correlation between early postoperative complications and well-known risk factors, including the phase angle, was performed. Results: Multivariate analysis revealed that the presence of two or more comorbidities (odds ratio [OR], 3.675) and hypoalbuminemia (OR, 4.059) were independent risk factors for overall complications, and female sex (OR, 2.993) was independent risk factor for severe complications. A low phase angle (OR, 2.901 and 4.348, respectively) and total gastrectomy (OR, 4.718 and 3.473, respectively) were independent risk factors for both overall and severe complications. Conclusions: Our findings show that preoperative low phase angle predicts the risk of overall and severe complications. Our findings suggest that BIA should be performed to assess the risk of postoperative complications in elderly patients with gastric cancer.

• 한국콘텐츠학회논문지
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• 제17권10호
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• pp.94-101
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• 2017

본 연구는 뇌졸중 편마비 환자 24명을 대상으로 마비측과 비마비측의 바이오 임피던스 값을 비교 분석하고자 하는 것이다. 본 연구에서는 2015년 10월부터 11월 까지 뇌졸중으로 진단 받은 편마비환자 24명을 대상으로 하였다. MultiScan 5000을 이용하여 바이오임피던스를 측정하였고 프래딕션마커(Prediction mark), 저항성분(resistance), 리액턴스(reactance), 위상각(phase angle)을 비교분석하였다. 뇌졸중 편마비 환자와 바이오임피던스 값의 비교분석을 위해 뇌졸중 편마비 가 아닌 일반인 6명의 오른쪽과 왼쪽을 비교분석하였다. 뇌졸중 편마비 환자의 마비측과 비마비측 부위에서 임피던스 값을 측정하여 정량화된 수치로 나타낸 결과 뇌졸중 편마비 환자의 마비측과 비마비측의 프래딕션마커(Prediction mark), 리액턴스(reactance), 위상각(phase angle)의 값의 유의한 차이를 보였다(p<0.05). 일반인을 대상으로 오른쪽과 왼쪽의 프래딕션마커(Prediction mark), 리액턴스(reactance), 위상각(phase angle)의 값의 유의한 차이를 보이지 않았다(p>0.05). 본 연구 결과를 통해 뇌졸중 편마비 환자의 마비측과 비마비측의 임피던스값의 유의한 차이가 있다는 것을 알 수 있었고 또한, 이를 통해 임상의 재활치료를 받는 뇌졸중 환자의 치료에 정량화된 수치로 측정할 수 있는 유용한 평가도구로서의 가능성을 제시하였다. 향후 연구에서는 임피던스 분석을 이용하여 뇌졸중환자의 마비측과 비마비측의 분석뿐만 아니라 다양한 대상군, 다양한 신체부위 그리고 재활치료 중재의 효과 등을 측정하는 연구가 필요할 것으로 보인다.

• 대한지역사회영양학회지
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• 제2권2호
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• pp.179-186
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• 1997

A new bioelectrical impedance method has been developed and evaluated. The electrodes; were made of stainless steel and electrical interfaces were created by an upright subject gripping hand electrodes and stepping onto foot electrodes. Eight tactile electrodes were in contact with surfaces of both hands and feet; thumb, palm and fingers, front sole, and rear sole. Automatic on-off switches were used to change current pathways and to measure voltage differences for target segments. Segmental body resistances and whole body resistance(RWHOLE)were measured in 60 healthy subjects. Segmental resistances of right arm(RRA), left arm(RLA), trunk(RT), right leg(RRL) and left leg(RLL)were310.0$\pm$61.6$\Omega$, 316.9$\pm$64.6$\Omega$, 25.1$\pm$3.4$\Omega$, 236.8$\pm$31.2$\Omega$ and 237.6$\pm$30.4$\Omega$, respectively. Individual segmental impedance indexes(Ht2/RRA, Ht2/RT, and Ht2 /RLA) were closely related to lean body mass(LBM)as measured by densitometry ranged from r=0.925 to 0.960. Ht2/(RRA+RT+RLA) predicted LBM slightly better(r=0.969) than the traditional index, Ht2/RWHOLE(r=0.964), supporting the accuracy of the segmental measurement. A multiple regression equation utilizing Ht2/RRA, Ht2/RT and Ht2/RRL predicted LBM with r=0.971. Ht2/RRA term of the regression contributed to more than 40$\%$ of the LBM prediction, indicating that lean mass of arm represented whole body LBM more closely than other body segments. The new bioimpedance method was characterized by upright posture, eight tactile electrodes, segmental measurements and utilization of electronic switches in comparison with the traditional method. The measurement with this new method was extremely reproducible, quick and easy to use.

• 한국항행학회논문지
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• 제18권6호
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• pp.582-587
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• 2014

본 연구는 장기간의 해상활동으로 의료기관 방문이 어려운 해상 활동자의 심혈관계질환 예측인자로 검사가 용이한 생체전기저항분석법 (BIA; bioelectrical impedance analysis)의 활용이 가능한지를 확인해보았다. 현재 심혈관성질환의 예측인자로 사용되고 있는 총콜레스테롤 측정치를 기준으로 BIA의 측정치와 관련성을 통계적 방법으로 분석한 결과 인체부위별 지방두께와 상관관계를 보였으며, 특히 왼쪽(왼) 허벅지의 지방두께가 총 콜레스테롤 측정치와 높은 상관관계를 나타냈다. 이 결과로 장기적인 해상 활동을 요하는 사람들은 BIA 검사를 통해 왼허벅지의 지방두께 변화를 심혈관질환의 예측인자로 활용할 수 있을 것이다. 하지만 선행연구의 부재로 후속연구가 필요하고 해상이라는 특수 상황이 고려된 측정도구의 정확성과 타당성 진단이 이루어져야 될 것으로 사료된다.

• 한국식품영양과학회지
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• 제26권3호
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• pp.514-520
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• 1997

The purpose of this study is to provide the reference data for estimating body composition and developing equations for prediction of percent body fat. This study was designed of two aspects: Comparison of percent body fat measurements between two operators. comparison of percent body fat measurements among four instruments. Percent body fat of college girls(n=71) aged 18-24 was measured by skinfold thickness, near-infratred interactance(Futrex-5000), and bioelectrical impedance analysis (TBF-105, Spectrum II). All measurements were duplicated & measured by two operators. The results are summarized as follows: Percent body fat observed from two operators had no significant difference. There was significant difference from four instruments. However, we found close relation between Skinfold thickness & TBF-105, Spectrum II & Near-infrared interactance. Four instruments have several assumptions and limitations. Therefore, many researches for developing new equations are required for Korean people.