• Title/Summary/Keyword: bio-impedance change

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Optimum electrode selection for measuring the abdominal pressure using bio-impedance method (비침습적 복압 측정을 위한 생체 임피던스 전극의 최적 위치 선정)

  • An, Yang-Su;Kim, Keo-Sik;Song, Chul-Gyu
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.46-48
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    • 2007
  • In this study, we determined the optimum electrode pair for measuring the abdominal pressure using bio-impedance method. Because impedance changes differ from a weight, a height, contractile force, volume of muscle and blood other or whatever of individuals, it was quantified using values of impedance change, correlation coefficient and SNR. Our results showed the optimum electrode pair (1, 9) which could detect impedance changes due to an increase of the intensity of the abdominal pressure. The correlation coefficient and quadratic function between the RMS values of EMG and the impedance changes were 0.87 and $y=0.0014x^2$+0.0620x+0.6958, respectively. It demonstrated that the abdominal pressure could be measured non-invasively and simply using bio-impedance method. We propose that this optimum electrode configuration would be useful for future studies involving the convenient measurement of abdominal pressure by ambulatory urodynamics monitoring study.

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Optimum Electrode Selection for Measuring Abdominal Pressure using Bio-Impedance Method (생체 임피던스 방법을 이용하여 복압을 측정하기 위한 최적 전극위치 선정)

  • Kim, Keo-Sik;Lee, Sang-Ok;Seo, Jeong-Hwan;Kim, Kyeong-Seop;Song, Chul-Gyu
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.7
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    • pp.1339-1342
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    • 2007
  • In this study, we determined the optimum electrode pair for measuring the abdominal pressure using bio-impedance method and compared with conventional methods. Because impedance changes differ from a weight, a height, contractile force, volume of muscle and blood other or whatever of individuals, it was quantified using values of impedance change, correlation coefficient and SNR. Our results showed the optimum electrode pair (1, 9) which could detect impedance changes due to an increase of the intensity of the abdominal pressure. The correlation coefficient and quadratic function between the RMS values of EMG and the impedance changes were 0.87 and $y=0.0014x^2+0.0620x+0.6958$, respectively. It demonstrated that the abdominal pressure could be measured noninvasively and simply using bio-impedance method. We propose that this optimum electrode configuration would be useful for future studies involving the convenient measurement of abdominal pressure by ambulatory urodynamics monitoring study.

A New Approach Method of Measuring Abdominal Pressure for Urodynamic Monitoring System (요역동학 측정시스템을 위한 새로운 복압측정 기법)

  • Seo, Jeong-Hwan;Kim, Keo-Sik;An, Yang-Su;Kim, Kyeong-Seop;Song, Chul-Gyu
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.6
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    • pp.1170-1176
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    • 2007
  • The conventional urodynamic monitoring is fulfilled by artificially filling a bladder with saline. Generally. it is difficult to evaluate the physiological functions of the storage and voiding of a bladder. With this aim, we constructed an ambulatory urodynamic monitoring (AUM) system and proposed a novel method estimating abdominal pressure by measuring bio-impedance variations. Our system was clinically evaluated for 10 patients. It turned out to be that as the intensity of the abdomen contraction increased, the amplitude of bio-impedance signal and the RMS value of EMG increased more as compared to those who observed during the rest mode. Also, we determined the optimum electrode pair for estimating the abdominal pressure using bio-impedance method and consequently compared with the conventional methods. Because impedance changes differ from a weight, a height, contractile force, volume of muscle and blood other or whatever of individuals, it was quantified in terms of impedance change, correlation coefficient and SNR Our results showed the optimum electrode pair (1,9) which could detect impedance changes due to the increase of the intensity in the abdominal pressure. The correlation coefficient and quadratic function between the RMS values of EMG and the impedance changes were 0.87 and $y=0.0014x^2+0.0620x+0.6958$, respectively. Thus, our system demonstrated that the abdominal pressure could be measured noninvasively and conveniently by simply estimating bio-impedance values. We propose that this optimum electrode configuration would be useful for the future studies involving the handy measurements of abdominal pressure with our suggested ambulatory urodynamics monitoring system.

Optimal Electrode Selection for Detection of Human Leg Movement Using Bio-Impedance (생체 임피던스를 이용한 인체 하지운동 출을 위한 최적 전극위치 선정)

  • 송철규;윤대영;이동헌;김승찬;김덕원
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.8
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    • pp.506-509
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    • 2003
  • This paper describes the possibility of analyzing gait pattern from the changes of the lower leg electrical impedance. This impedance was measured by the four-electrode method. Two current electrodes were applied to the thigh, knee, and foot., and two potential electrodes were applied to the lateral, medial, and posterior position of human leg. The correlation coefficients of the joint angle and the impedance change from human leg movement was obtained using a electrogoniometer and 4ch impedance measurement system developed in this study. We found the optimal electrode position for knee and ankle joint movements based on high correlation coefficient, least interference, and maximum magnitude of impedance change. The correlation coefficients of the ankle, knee, and the hip movements were -0.913, 0.984 and 0.823, respectively. From such features of the human leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level. This system showed feasibility that lower leg movement could be easily measured by impedance measurement system with a few skin-electrodes.

Optimal Electrode Displacement for Motion Analysis using Bio-impedance (임피던스 방식의 동작분석을 위한 최적전극 선정)

  • 송철규;변용훈;윤대영;이명권;김거식;송창훈;김경섭;김수찬;김덕원
    • Proceedings of the IEEK Conference
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    • 2003.07c
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    • pp.2887-2890
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    • 2003
  • This paper describes the possibility of analyzing gait pattern from the variation of the lower leg electrical impedance. This impedance is measured by the four-electrode method. Two current electrodes are applied to the thigh, knee, and foot, and two potential electrodes are applied to the lateral, medial, and posterior position of lower leg. The correlation coefficients of the joint angle and the impedance change from human leg movement was obtained using electrogoniometer and 4ch impedance measurement system developed in this study. We found the optimal electrode position for ankle, knee and hipjoint movements based on high correlation coefficient, least interference, and maximum magnitude of impedance change. The correlation coefficients of the ankle, knee, and the hip movements -0.87, 0.957 and 0.80. respectively. From such features of the lower leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level. This system showed possibility that lower leg movement could be easily measured by impedance measurement system with a few skin-electrodes.

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A Study on Sensing Characteristics of Carbon Nanotube Smart Composite Nano Sensors Based on Electrical Impedance Measurement (탄소나노튜브 스마트 복합소재의 전기적 임피던스 변화를 이용한 나노센서의 센싱 특성 연구)

  • Kang, I.P.
    • Journal of Power System Engineering
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    • v.13 no.1
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    • pp.65-71
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    • 2009
  • To address the need for new intelligent sensing, this paper introduces nano sensors made of carbon nanotube (CNT) composites and presents their preliminary experiments. Having smart material properties such as piezoresistivity, chemical and bio selectivity, the nano composite can be used as smart electrodes of the nano sensors. The nano composite sensor can detect structural deterioration, chemical contamination and bio signal by means of its impedance measurement (resistance and capacitance). For a structural application, the change of impedance shows specific patterns depending on the structural deterioration and this characteristic is available for an in-situ multi-functional sensor, which can simultaneously detect multi symptoms of the structure. This study is anticipated to develop a new nano sensor detecting multiple symptoms in structural, chemical and bio applications with simple electric circuits.

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Leg Motion Monitoring using Bio-impedance Signal (생체 임피던스 신호를 이용한 하지동작 모니터링)

  • 송철규;변용훈;윤대영;김거식;임정모;전희천;권승범;이정훈;이명권
    • Proceedings of the IEEK Conference
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    • 2003.07c
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    • pp.2891-2894
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    • 2003
  • This paper describes the possibility of analyzing gait pattern from the variation of the lower leg electrical impedance. This impedance is measured by the four-electrode method. Two current electrodes are applied to the thigh and foot., and two potential electrodes are applied to the lateral aspect. medial aspect, and posterior position of lower leg. We found the optimal electrode position for knee and ankle joint movements based on high correlation coefficient, least Interference, and maximum magnitude of impedance change. From such features of the lower leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level.

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Analysis of Lower Leg Movement Using Bio-impedance Technique (바이오 임피던스를 이용한 하지 운동분석)

  • Song, C.G.;Song, C.H.;Lee, M.G.;Kim, S.C.;Kim, J.C.;Seo, J.H.
    • Proceedings of the KIEE Conference
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    • 2002.11c
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    • pp.414-417
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    • 2002
  • This paper describes the possibility of analyzing gait pattern from the variation of the lower leg electrical impedance. This impedance is measured by the four-electrode method. Two current electrodes are applied to the thigh and foot., and two potential electrodes are applied to the lateral aspect, medial aspect, and posterior position of lower leg. We found the optimal electrode position for knee and ankle joint movements based on high correlation coefficient, least interference, and maximum magnitude of impedance change. From such features of the lower leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level.

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Measurement of Blood Flow Variation using Impedance Method (임피던스법을 이용한 혈류량 변화 측정)

  • Jeong Do-Un;Kang Seong-Chul;Jeon Gye-Rock
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.693-696
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    • 2006
  • In this study, we made the system to measure variation of blood flow using bio-electrical impedance analysis method. The system, which could measure variation of impedance according to pressure change by artificial pressure, consists of pressure measurement and impedance measurement by 4-electrode method. Pressure measurement splits into semiconducting pressure sensor and electronic circuit for processing output signal. In addition, impedance measurement splits into constant current source circuit and lock-in amplifier for detection impedance signal. We experimented feature of impedance measurement using standard resistance to evaluate the system characteristic. As well as, we experimented to estimate variation of blood flow by measuring impedance and blood flow resistance ratio using mean arterial pressure and variation of blood flow with experimental group. As result of this study, blood flow resistance ratio and variation of blood flow were definitely in inverse proportion and were -0.96776 as correlation coefficient by correlation analysis.

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Development of a Real-Time Soil Moisture Meter using Oscillation Frequency Shift Method

  • Kim, Ki-Bok;Lee, Nam-Ho;Lee, Jong-Whan;Lee, Seoung-Seok;Noh, Sang-Ha
    • Agricultural and Biosystems Engineering
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    • v.2 no.2
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    • pp.63-68
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    • 2001
  • The objective of this study was to develop a real-time soil moisture meter using RF impedance. The impedance suchas capacitance and resistance (or conductance) was analyzed using parallel cylinder type capacitance probe(C-probe) and Q-meter (HP4342). The capacitance and conductance of soil increased as volumetric water content increased. The 5 MHz of modified Colpitts type crystal oscillator was designed to detect the capacitance change of the C-probe with moist soil. A third order polynomial regression model was proposed to describe the relationship between RF impedance and volumetric water content. The prototype real time moisture meter consisted of the C-probe, sample container, oscillator, frequency counter and related signal processing units. The calibration equation for measurement of volumetric moisture content of soil was developed and validated. The correlation coefficient and root mean square error between measured volumetric water content by oven method and predicted values by prototype moisture meter for unknown soil samples were 0.984 and 0.032$cm^3$$cm\^3$, respectively.

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