权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

STUDY OF THE FLUID DISTRIBUTION BY MULTI-FREQUENCY IMPEDANCE CT

多频阻抗CT对流体分布的研究

基本信息

批准号：
08680934
负责人：
SAKAMOTO Katsuyuki
金额：
$ 1.54万
依托单位：
Kitasato University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

1. We have tried to estimate the intra- and extra-cellular fluid distribution in the specified tissue from the frequency characteristics of tissue impedance in a β dispersion region. In order to extract the information of the specified tissue from the impedance measured on the body surface, we designed and produced the multi-frequency impedance CT.2. There is a important problem we must solve before applying the multi-frequency impedance CT. The relation between the intra- and extra-cellular fluid distribution and the electrical impedance of the specific tissue is not quantitatively understood yet. In order to collaborate the relation, we made the following three experiments.(1) Changing the NaCl concentration in plasma controlled the size of erythrocytes. We experimentally measured the impedance change of the flowing blood, hematcrit and the size of erythrocytes. And discussed the relation theoretically. From the results, it is found that the resistance of tissue at low frequency is related to the extra-cellular fluid volume and that at high frequency the extra- and intra-cellular fluid volume. And the intra-cellular resistance changes in proportion to the change of intracellular fluid volume but the change rate of the extra-cellular resistance is less than that of the extra-cellular fluid volume. The change rate of the extra-cellular fluid depends upon the cell size and arrangement. Under these fundamental results,(2) we estimated the shift fluid volume in the intra- and extra-cellular by the change of the leg impedance during HD, HDF and ECUM hemodialysis. The change of leg impedance provides us the information about the condition of the intra- and extra-cellular fluid distribution change.(3) When the tissue temperature rises up during hyperthermia therapy, the tissue impedance decreases and the blood volume and flow in the tissue increase. We could estimate the blood volume change by the multi-frequency impedance method.

1. 我们试图从β色散区组织阻抗的频率特性来估计特定组织中的细胞内和细胞外流体分布。为了从体表测量的阻抗中提取指定组织的信息，我们设计并制作了多频阻抗CT.2。在应用多频阻抗CT之前，必须解决一个重要的问题。细胞内和细胞外的液体分布与特定组织的电阻抗之间的关系尚未定量了解。为了配合这个关系，我们做了以下三个实验。(1)改变血浆中NaCl浓度可控制红细胞大小。实验测量了血流、红细胞和红细胞大小的阻抗变化。并从理论上讨论了二者的关系。结果表明，低频时组织阻力与细胞外液体积有关，高频时组织阻力与细胞外液和细胞内液体积有关。细胞内电阻随细胞内液量的变化成正比，细胞外电阻的变化率小于细胞外液量的变化率。细胞外液的变化率取决于细胞的大小和排列。在这些基本结果的基础上，(2)我们通过HD、HDF和ECUM血液透析期间腿部阻抗的变化来估计细胞内和细胞外的位移液量。腿阻抗的变化为我们提供了细胞内和细胞外体液分布变化的信息。(3)热疗过程中，当组织温度升高时，组织阻抗降低，组织内血容量和流量增加。我们可以用多频阻抗法来估计血容量的变化。