目的通过提出一种计算人体动脉树输入阻抗的递归算法,分析动脉树各参数对输入阻抗的影响,为动脉树生理和病理变化分析提供参考。方法利用由大动脉和主要外周动脉构成的55段人体动脉树建立分布式电网络模型,通过设定电网络模型外周阻力,建立动脉树单向数据链表,采用递归算法计算动脉树升主动脉的输入阻抗。在此基础上比较不同动脉顺应性、外周阻力和动脉长度、内径、壁厚等参数对输入阻抗的影响。结果计算结果与实验数据和其他模型结果相一致,验证了该方法的有效性。不同参数对动脉树输入阻抗的影响有较大差异且呈现各自特征。结论输入阻抗能有效地反映动脉树血液动力学参数的变化情况,是人体动脉树生理病理诊断的重要参考。
Objective In order to provide a reference for analysis of the pathophysiological changes of human ar-terial tree,the effects of the arterial parameters on input impedance of arterial tree were studied by proposing a recursive algorithm to calculate the input impedance.Method A distributed electric network model was construc-ted for the arterial tree which consisted of 55 segments accounting for all the central vessels and major peripheral arteries.By setting up the peripheral resistance of the model and constructing a unilateral data-link list of the arte-rial tree,the recursive algorithm was employed to compute the input impedance of ascending aorta in the arterial tree.Then,comparisons of the effects of arterial compliance,peripheral resistance,length,internal radius and wall thickness on the input impedance were made based on the recursive algorithm.Results The computational results were in accord with experimental data and results of other models,and proved the validity of the model and algorithm.The input impedances of the arterial tree showed significant influence with different characteristics for different parameters.Conclusions The input impedance of arterial tree can reflect the changes of the hemo-dynamic parameters effectively,which is an important reference for the pathophysiological diagnosis of human ar-terial tree.