Model for the dielectric properties of human lung tissue against frequency and air content
Model for the dielectric properties of human lung tissue against frequency and air content
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DOI：
10.1007/bf02510980
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发表时间：
1997-11-01
影响因子：
3.2
通讯作者：
Brown, BH
中科院分区：
文献类型：
--
作者：
Nopp, P;Harris, ND;Brown, BH
肺的电阻抗断层扫描频谱测量来自9个正常受试者，在9.6 kHz-1.2 MHz的频率范围内。结果表明，相对于功能剩余容量的电阻率Rho‘(FRC)随吸气量V几乎线性增加，曲线斜率随频率f增大而增大，在任何给定频率下，相对9.6 kHz的电阻率Rho’(9.6 kHz)随F减小。Rho‘(9.6 kHz)曲线与log(10)(F)大致呈线性关系。基于对测量结果的讨论，设计了一个包含毛细血管外血管和肺泡的肺组织数学模型，肺泡的壁由充满血液的毛细血管、上皮细胞和细胞间液体组成。用该模型解释了Rho‘(FRC)随空气含量的增加而变薄的原因。Rho‘(9.6 kHz)曲线的近线性形状归因于毛细血管外血管、上皮细胞、血液和毛细血管网络引起的四个部分重叠的主要弥散。
Electrical impedance tomographic spectroscopy measurements of the lungs are taken from nine normal subjects, in the frequency range 9.6 kHz-1.2 MHz. The results show that resistivity rho'(FRC) relative to functional residual capacity increases almost linearly with inspiration volume V, with the slope of the curve increasing with frequency f. Resistivity rho'(9.6 kHz) relative to 9.6 kHz decreases with f. rho'(9.6 kHz) increases with V, at any given frequency. Curves for rho'(9.6 kHz) show a roughly linear trend with log(10)(f). Based on a discussion of the measurement results, a mathematical lung tissue model is designed that involves extra-capillary blood vessels and alveoli, the walls of which consist of blood-filled capillaries, epithelial cells and intercellular liquid. Using this model, the increase in rho'(FRC) with V is explained by the thinning of alveolar walls with increasing air content. The almost linear shape of curves for rho'(9.6 kHz) is attributed to four partly overlapping main dispersions caused by extra-capillary blood vessels, epithelial cells, blood and the capillary network.