Elucidation of time to lead to the onset of pressure ulcers using the cells and animal experiment

皮肤组织可视为以组织内流动的血液为液相、胶原纤维为固相构成的固液两相粘弹性多孔材料。由于皮肤组织通过经皮压力而被加固，因此重要的是定量研究孔隙率下降与血液循环障碍之间的关系。测量了由于兔耳蠕变变形引起的组织固结和随后的血流变化。组织内的血流顺应性CS表示为孔隙率P的指数函数CS=345.3P-2.68（相关系数R2=0.999），并且发现在20 mm Hg或更高的经皮压力下，组织内的血流量迅速下降。为了给压疮提供高水平的安全性和生物相容性，必须确保足够的血液流向压疮所在的皮肤组织。

Skin tissue can be regarded as a solid-liquid biphasic visco-elastic porous material constructed by with the blood flowing in tissues as the liquid phase and collagen fibers as the solid phase. As skin tissues are consolidated by percutaneous pressure, it is important to quantitatively study the relationship between decline in porosity and blood circulation disorder. Consolidation of tissues due to creep deformation of rabbit ears and subsequent changes in blood flow were measured. Blood flow compliance CS inside tissues is expressed as an exponential function of porosity P as CS=345.3P-2.68 (correlation coefficient R2=0.999), and it came to light that blood flood inside tissues rapidly decline under the percutaneous pressure of 20 mm Hg or more. In order to give a high level of safety and biocompatibility to pressure ulcers, it is necessary to ensure that adequate blood flows to the skin tissue, where pressure ulcers is mounted.