Estimation of the body fluid shift by the multi-frequency admittance method

1)经济综合征：我提出了估算腿部变化量的新算法。当志愿者静坐1小时时，我测量了腿部的电导纳，并估计了腿部的血量变化，细胞内和细胞外液体体积变化。腿部未见细胞内及细胞外液体改变。2)人工透析过程中排液量得到了一种新的估计人工透析过程中排液量的良好算法。我得到了估计的除液量与测量的除液量吻合得很好。我们还估计了人工透析期间细胞内和细胞外液体容量的变化。3)脂肪体积的估计我从理论上讨论了测量胃脂肪体积的电极布置。我们计算了不同电极布置下人体表面的电位分布。4)用有限元法对组织导纳进行了基础研究，从测得的导纳位点得到了组织导纳和胞外流体导纳。在低频时，阴影效应非常大，因此测量的低频导纳被低估了。我得到了以下结果。当细胞浓度较低时，这种效应较大。另一方面，细胞浓度越高，影响越小。边界元法（BEM）对组织导纳的基础研究活组织的时间常数的测量正好反映了组织的Col-Col分布。计算结果表明，细胞膜电容对Col-Col分布有很大影响。

1) Economy syndromeI produce the new algorism for estimating the change volume in leg.I measured legs electrical admittance and estimated blood volume change, intra and extra-cellular fluid volume change in legs, when volunteers were sitting for 1 hour. There were no intra and extra-cellular fluid change in leg.2) Fluid removal during artificial dialysisI obtained the new good algorism for estimating fluid removal during artificial dialysis.I obtained that the estimated fluid removal agreed well with the measured fluid removal. We also estimated intra and extra-cellular fluid volume change during artificial dialysis.3) Estimation of fat volumeI theoretically discussed the electrode arrangement for measuring fat volume in stomach. We calculated the potential distribution on the surface of the body under the various electrode arrangements.4) Basic study of tissue admittance by finite element methodIntra and extra-cellular fluid admittance are obtained from the measured admittance loci. Shadow effect is very large at low frequency Therefore, measured admittance at low frequency is underestimated. I obtained the following results. When the concentration of cells is low, this effect is large. On the other hand, the concentration of cells is high, the effect is small.5) Basic study of tissue admittance by boundary element method (BEM)Measured time constant of living tissue just shows the Col-Col distribution. From calculation results, I concluded that cell membrane capacitance greatly contributes greatly to the Col-Col distribution.