Research on human skin anatomy reveals its complex multi-scale, multi-phase nature, with up to 70% of its composition being bounded and free water. Fluid movement plays a key role in the skin's mechanical and biological responses, influencing its time-dependent behavior and nutrient transport. Poroelastic modeling is a promising approach for studying skin dynamics across scales by integrating multi-physics processes. This paper introduces a hierarchical two-compartment model capturing fluid distribution in the interstitium and micro-circulation. A theoretical framework is developed with a biphasic interstitium -- distinguishing interstitial fluid and non-structural cells -- and analyzed through a one-dimensional consolidation test of a column. This biphasic approach allows separate modeling of cell and fluid motion, considering their differing characteristic times. An appendix discusses extending the model to include biological exchanges like oxygen transport. Preliminary results indicate that cell viscosity introduces a second characteristic time, and at high viscosity and short time scales, cells behave similarly to solids. A simplified model was used to replicate an experimental campaign on short time scales. Local pressure (up to 31 kPa) was applied to dorsal finger skin using a laser Doppler probe PF801 (Perimed Sweden), following a setup described in Fromy Brain Res (1998). The model qualitatively captured ischemia and post-occlusive reactive hyperemia, aligning with experimental data. All numerical simulations used the open-source software FEniCSx v0.9.0. To ensure transparency and reproducibility, anonymized experimental data and finite element codes are publicly available on GitHub.

翻译：人体皮肤解剖学研究表明其具有复杂的多尺度、多相特性，其中高达70%的成分为结合水与自由水。流体运动在皮肤的力学与生物学响应中起关键作用，影响其时间相关行为与营养输送。多孔弹性建模通过整合多物理过程，为跨尺度研究皮肤动力学提供了有效途径。本文提出一种分层双室模型，用于描述组织间隙与微循环系统中的流体分布。理论框架采用双相组织间隙模型——区分组织间隙流体与非结构细胞——并通过一维柱体固结试验进行分析。该双相方法可分别模拟细胞与流体运动，兼顾二者不同的特征时间尺度。附录探讨了将模型扩展至包含氧气输送等生物交换过程。初步结果表明，细胞黏性会引入第二特征时间，在高黏性与短时间尺度下，细胞表现出类固体行为。采用简化模型复现了短时间尺度的实验方案。根据Fromy Brain Res (1998)描述的配置，使用激光多普勒探头PF801（Perimed Sweden）对手背皮肤施加局部压力（最高31 kPa）。该模型定性捕捉了局部缺血与闭塞后反应性充血现象，与实验数据趋势一致。所有数值模拟均采用开源软件FEniCSx v0.9.0。为确保透明度与可重复性，匿名实验数据与有限元代码已在GitHub平台公开。