Goal: Fractional-order Windkessel model is proposed to describe the aortic input impedance. Compared with the conventional arterial Windkessel, the main advantage of the proposed model is the consideration of the viscoelastic nature of the arterial wall using the fractional-order capacitor (FOC). Methods: The proposed model, along with the standard two-element Windkessel, three-element Windkessel, and the viscoelastic Windkessel models, are assessed and compared using in-silico data. Results: The results show that the fractional-order model fits better the moduli of the aortic input impedance and fairly approximates the phase angle. In addition, by its very nature, the pseudo-capacitance of FOC makes the proposed model's dynamic compliance complex and frequency-dependent. Conclusions: The analysis of the proposed fractional-order model indicates that fractional-order impedance yields a powerful tool for a flexible characterization of the arterial hemodynamics.

中文翻译：

---

分数阶动脉 Windkessel 作为主动脉输入阻抗模型的评估

目标：提出分数阶 Windkessel 模型来描述主动脉输入阻抗。与传统的动脉 Windkessel 相比，该模型的主要优点是使用分数阶电容器 (FOC) 考虑了动脉壁的粘弹性。方法：所提出的模型以及标准的二元 Windkessel、三元 Windkessel 和粘弹性 Windkessel 模型均使用计算机数据进行评估和比较。结果：结果表明，分数阶模型更适合主动脉输入阻抗的模量，并且相当接近相位角。此外，就其本质而言，FOC 的赝电容使得所提出模型的动态顺应性复杂且与频率相关。结论：对所提出的分数阶模型的分析表明，分数阶阻抗为灵活表征动脉血流动力学提供了强大的工具。