Characterization of embryonic aortic impedance with lumped parameter models.
Characterization of embryonic aortic impedance with lumped parameter models.
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用集总参数模型表征胚胎主动脉阻抗。
DOI：
10.1152/ajpheart.1997.273.1.h19
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Keller,BB
中科院分区：
文献类型：
--
作者：
Yoshigi,M;Keller,BB
我们系统地构建和分析了18个模拟电路模型来表征胚胎动脉阻抗。我们同时测量了腹主动脉背侧压力和流量，并计算了24期鸡胚(n=15)的实验阻抗。用热探头改变周期长度，以提高阻抗谱的频率分辨率。模型根据框架以及电感和电阻项的位置进行分类。如果模型不能再现实验阻抗谱的基本特征，则被排除在外。采用加权最小二乘参数优化法对模型阻抗曲线与实验阻抗数据进行拟合。未能收敛参数或显示过度参数化的模型也被排除在外。我们用F检验、Akaike信息准则和Schwarz准则来评估频域的拟合优度，以确定最佳拟合模型。在传统的三元件Winkesel模型中加入了串联电感项，通过再现模数起伏和相位过零来改进拟合(P<；0.001)。因此，尽管在规模和几何上有很大的不同，胚胎和成熟的血管系统可以用集中参数电路模型来描述。
We systematically constructed and analyzed 18 analog circuit models to characterize embryonic arterial impedance. We measured simultaneous dorsal aortic pressure and flow, and we calculated experimental impedance in stage 24 chick embryos (n = 15). Cycle length was altered with thermal probes to improve frequency resolution of the impedance spectrum. Models were categorized according to the framework and the location of inductance and resistance terms. Models were excluded if they failed to reproduce the fundamental characteristics of the experimental impedance spectrum. We used weighted least-square parameter optimization to fit the model impedance curves to the experimental impedance data. Models that failed to converge parameters or revealed overparameterization were also excluded. We assessed goodness of fit in the frequency domain with the F-test, Akaike information criterion, and Schwarz criterion to determine the best-fit model. The addition of a serial inductance term to the traditional three-element windkessel model improved fit by reproducing modulus fluctuation and phase zero crossing (P < 0.001). Thus, despite dramatic differences in scale and geometry, the embryonic and mature vascular systems can be described using lumped parameter circuit models.