Visser K R, Lamberts R, Poelmann A M, Zijlstra W G
Pflugers Arch. 1977 Mar 11;368(1-2):169-71. doi: 10.1007/BF01063473.
In an anaesthetized dog an exchange transfusion was carried out with stroma-free haemoglobin solution. The total circulating blood volume was kept constant. The heart-syncronous changes in the thoracic electrical impedance (Zo) were measured before and after the exchange transfusion. Zo consists of a parallel connection of a tissue impedance (Zt) and a blood impedance (Zb). With the aid of this model for Zo the relative variations in Zb (delta Zb/Zb) were calculated from the relative variations in Zo (delta Zo/Zo). The marked decrease of delta Zb/Zb during the experiment can only be explained by the fact that apart from the heart-synchronous changes in vascular volume the impedance changes are also caused by flow dependent changes in the electrical conductivity of blood caused by variations in orientation of the erythrocytes.
在一只麻醉的狗身上，用无基质血红蛋白溶液进行了换血输血。总循环血量保持恒定。在换血输血前后测量了胸段电阻抗（Zo）的心脏同步变化。Zo由组织阻抗（Zt）和血液阻抗（Zb）并联组成。借助这个Zo模型，根据Zo的相对变化（δZo/Zo）计算出Zb的相对变化（δZb/Zb）。实验过程中δZb/Zb的显著降低只能用以下事实来解释：除了血管容量的心脏同步变化外，阻抗变化还由红细胞取向变化引起的血液电导率的流量依赖性变化所导致。
