有限要素法による生体インピーダンスの解析  [in Japanese] ANALYSIS OF BIOIMPEDANCE BY A FINITE ELEMENT METHOD  [in Japanese]

著者らは, これまで, β分散領域における前腕の局所生体インピーダンスを4電極法により測定してきた. 本研究では, 3次元有限要素解析により, 測定データと生体組織の構造や特性との関係について解析を行った. 有限要素解析においては, 筋肉, 脂肪層, 骨の各組織を考慮した. 電位分布より, 生体インピーダンス値における骨の影響は0.5[%]以下であり, 無視できることを確認した. 実測値より, 皮下組織厚Tsと細胞外液抵抗Reにおいて相関が見られ, 有限要素解析でも確認できた. また実測値と解析結果をフィッテングさせることにより, 脂肪層, 筋肉の各導電率が0.137[S/m], 0.53[S/m]と推定できた.

Local tissue impedance of the forearm has been measured by a four electrode method in β dispersion region. The objective of this study is to investigate the relations between the measured data and the structural properties based on a three dimensional finite element analysis, considering the electrical properties of muscle, fatty tissue and bone. In the calculated potential distributions, the influence of the bone for the measured impedance is less than 0.5 [%] and may be neglected. In experiments, the thickness Ts of the subcutaneous tissue correlates strongly with the extra-cellular resistance Re. The relation is also confirmed by the finite element analysis. The conductivities of the fatty tissue and the muscle are estimated by fitting the analytical results to the measured data. The conductivity of the fatty tissue may be about 0.137 [S/m], that of the muscle is about 0.53 [S/m].