不同电极距离下人体小腿组织细胞内外液电阻率的测量

目的观察不同电极距离下人体小腿细胞内外液电阻率的均匀性,探究测量系统的可行性,以便应用此系统测量健康信息。方法采用四电极生物阻抗谱法,激励电极将1~100 kHz恒流电流施加到人体小腿两端,测量电极采集电压和相角,电极距离分别为5 cm、10 cm、15 cm。测量10例健康受试者,计算得到细胞内外液的阻抗值和电阻率。结果随两电极间距离的增加,细胞内外液阻抗均极显著增加,阻抗的增加与距离高度相关;细胞内外液电阻率随距离仅有小幅增加,5 cm和15 cm之间有显著性差异,与小腿有效截面积随距离缩小有关。细胞内外液电阻率之比接近1,且不随电极距离的变化而改变。结论健康人体小腿组织的电阻率比较均匀,细胞内外液电阻率基本相等。

Measurement of the resistivity of extracellular and intracellular fluids in lower leg at different electrode distances

Objective To explore the feasibility of tissue fluid resistivity measurement for healthcare management, we evaluated the uniformity of the extracellular (ρe ) and intracellular (ρi ) fluid resistivity in a lower leg ( by measuring at different electrode distances) . Methods Ten health volunteers were involved in the test with a four?electrode bioimpedance spectroscopy. The measurement was performed with excitation frequencies from 1 kHz to 100 kHz. Two measuring electrodes were set on one lower leg at the distances of 5 cm, 10 cm and 15 cm. Voltage amplitude, phase angle,ρe and ρi were analyzed. Results The measured impedance increased with the distance of the measuring electrodes, and the resistivity changed little with the distance. No obvious difference between extracellular and intracellular fluid resistivity was observed. In addition, voltage amplitude and phase angle were influenced by the frequencies of excitation signals. Conclusions The resistivity in a lower leg measured with the four?electrode bioimpedance spectroscopy is likely uniform. The resistivities of extracellular fluid and intracellular fluid are similar.