Mechanical Engineering Department, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085, USA.
Mechanical Engineering Department, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085, USA.
Comput Methods Programs Biomed. 2023 Aug;238:107612. doi: 10.1016/j.cmpb.2023.107612. Epub 2023 May 16.
Blood flow rate and pressure can be measured in vivo by invasive and non-invasive techniques in the large vessels of the hepatic vasculature, but it is not possible to do so along the entire liver circulatory system. Here, we develop a novel 1D model of the liver circulatory system to obtain the hemodynamic signals from macrocirculation to microcirculation with a very low computational cost.
The model considers structurally well-defined elements that constitute the entire hepatic circulatory system, the hemodynamics (the temporal-dependence of the blood flow rate and pressure), and the elasticity of the vessel walls.
Using flow rate signals from in vivo measurements as inputs in the model, we obtain pressure signals within their physiological range of values. Furthermore, the model allows to get and analyze the blood flow rate and pressure signals along any vessel of the hepatic vasculature. The impact of the elasticity of the different model components on the inlet pressures is also tested.
A 1D model of the entire blood vascular system of the human liver is presented for the first time. The model allows to obtain the hemodynamic signals along the hepatic vasculature at a low computational cost. The amplitude and shape of the flow and pressure signals has hardly been studied in the small liver vessels. In this sense, the proposed model is a useful non-invasive exploration tool of the characteristics of the hemodynamic signals. In contrast to models that partially address the hepatic vasculature or those using an electrical analogy, the model presented here is made entirely of structurally well-defined elements. Future works will allow to directly emulate structural vascular alterations due to hepatic diseases and studying their impact on pressure and blood flow signals at key locations of the vasculature.
血流率和压力可通过侵入性和非侵入性技术在肝脉管系统的大血管中进行体内测量，但无法沿整个肝循环系统进行测量。在此，我们开发了一种新的肝循环系统 1D 模型，以便以非常低的计算成本从宏观循环获得血流信号到微循环。
该模型考虑了构成整个肝循环系统的结构明确的元素、血液动力学（血流率和压力的时间依赖性）以及血管壁的弹性。
使用体内测量的血流率信号作为模型的输入，我们获得了在其生理范围内的压力信号。此外，该模型允许获取和分析肝脉管系统中任何血管的血流率和压力信号。还测试了不同模型组件的弹性对入口压力的影响。
首次提出了人体肝整个血管系统的 1D 模型。该模型允许以低计算成本沿肝脉管系统获得血流动力学信号。在小肝血管中，对血流和压力信号的幅度和形状的研究很少。在这个意义上，所提出的模型是对血流动力学信号特征进行非侵入性探索的有用工具。与部分解决肝脉管系统的模型或使用电模拟的模型不同，这里提出的模型完全由结构明确的元素组成。未来的工作将允许直接模拟由于肝疾病引起的结构血管改变，并研究它们对血管关键部位的压力和血流信号的影响。
