Department of Special Diagnosis, 94th Hospital of People's Liberation Army of China, Jiangxi Nanchang, China.
Med Phys. 2012 Feb;39(2):1042-5. doi: 10.1118/1.3678987.
The aim of the present study is to investigate an impedance change equation suited with the measurement of the impedance cardiograph (ICG).
Based on a parallel impedance model and Ohm's law, an impedance change equation differed from Nyboer's equation is deduced. It is verified with the experiments of the impedance cardiography in 100 healthy adults.
This equation shows that the thoracic impedance change (ΔZ) is directly proportional to the value of the volume change (ΔV) of the blood vessel, to the ratio of the basic impedance to the body height (Z(0)/H), while it is inversely proportional to the square of the chest circumference (C(t) (2)). These are supported by the experimental results in the measurement of the ICG.
The equation proposed in the present paper is coincident with the actual condition in the measurement of the ICG.
本研究旨在探讨一种适用于阻抗心图测量的阻抗变化方程。
基于平行阻抗模型和欧姆定律，推导出一个与 Nyboer 方程不同的阻抗变化方程。通过对 100 名健康成年人的阻抗心图实验进行验证。
该方程表明，胸腔阻抗变化（ΔZ）与血管容积变化（ΔV）成正比，与基本阻抗与身高的比值（Z(0)/H）成正比，与胸腔周长的平方（C(t) (2)）成反比。这些结果在阻抗心图的测量实验中得到了支持。
本文提出的方程符合阻抗心图测量的实际情况。
