オオミネ, ユウケン Department of Surgery, Awa Hospital Tokushima Prefectural Welfare Federation on Agricaltural Cooperative
森本, 忠興 Department of Adult and Gerontological Nursing, School of Health Sciences, The University of Tokushima 徳島大学 教育研究者総覧 KAKEN研究者をさがす
木内, 陽介 Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Tokushima 徳島大学 教育研究者総覧 KAKEN研究者をさがす
入谷, 忠光 Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Tokushima 徳島大学 教育研究者総覧 KAKEN研究者をさがす
竹内, 美惠子 Department of Maternal and Pediatric Nursing, School of Health Sciences, The University of Tokushima 徳島大学 教育研究者総覧
葉久, 真理 Department of Maternal and Pediatric Nursing, School of Health Sciences, The University of Tokushima 徳島大学 教育研究者総覧 KAKEN研究者をさがす
西谷, 弘 Department of Radiology, Institute of Health Biosciences The University of Tokushima Graduate School 徳島大学 教育研究者総覧 KAKEN研究者をさがす
The purposes of this study were to estimate the electrical conductivity of tissues by non-invasively measuring the electrical bio-impedance, to develop a new method for tissue diagnosis, i.e., electrical impedance tomography (EIT). Tissue models were first designed taking into consideration the distribution of the fat tissue, muscle and bone in the human forearm, and then the intra-tissue distributions of electrical potential and field, and the electrical impedance in the models was theoretically analyzed by the three-dimensional finite element method. The electrical impedance of both forearms was measured in healthy human subjects, and estimated the electrical conductivity of individual local tissues. The results of the analysis showed that the distributions of electrical potential and field were affected by the presence of fat tissue but not by the presence or absence of bone. In addition, as a result of calculation of the electrical resistance of the extracellular fluid (Re) in each model, it was found that the value of bio-impedance was influenced by the presence of fat tissue, and the value of bio-impedance was increased by the intervention of a fat layer.
The electrical conductivity estimated by fitting the observed values to the values obtained by finite element analysis was 0.40 S/m and 0.15 S/m for male muscle and fat tissue, and 0.35 S/m and 0.11 S/m for female muscle and fat tissue, respectively. The sex difference in the slope of linear approximation in the estimation of electrical conductivity of the males and females was thought to be due to sex differences in the properties and structure of fat tissue. These results suggest that local tissues can be diagnosed differentially and electrically by percutaneous measurement of local bio-impedance and subsequent estimation of the electrical conductivity of each tissue.
The journal of medical investigation : JMI
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