Jacquet Emmanuelle, Josse Gwendal, Khatyr Fouad, Garcin Camille
University of Franche Comte, FEMTO-ST Institute, CNRS UMR 6174, Besançon, France.
Skin Res Technol. 2008 Feb;14(1):1-7. doi: 10.1111/j.1600-0846.2007.00259.x.
The precise determination of skin's mechanical properties is still an open question. When performing an in vivo test, the piece of skin tested is not as well defined as it is in material testing. Moreover, the body zone and the body posture imply an initial stress on the skin. Consequently, a precise mechanical analysis needs a precise measurement of the natural skin tension.
A new method and the relative device are presented. It is based on an extensiometry test. Skin is tested not only in traction but also in compression. The tested skin sample is well defined and protected from surrounding effects by follower tabs. The size and shape of the device have been optimised by a finite element modelisation.
The method was tested with elastomers pre-tensioned at different loads. It is shown that the initial tension can be retrieved with good precision. Tests were then performed in vivo on the forearm for different arm positions. It is shown that initial tension could be only clearly determined for the highest skin tension, although the skin presented very different traction behaviour with different arm positions.
It is shown how body posture influences measurements. An innovative method for easily determining initial tension is presented. Nevertheless, further tests and device improvements are needed to apply this skin tension measurement for different body zones and body postures.
皮肤力学性能的精确测定仍是一个悬而未决的问题。在进行体内测试时，所测试的皮肤部位不像材料测试那样明确界定。此外，身体部位和身体姿势意味着皮肤存在初始应力。因此，精确的力学分析需要精确测量皮肤的自然张力。
提出了一种新方法及相关装置。它基于引伸计测试。不仅对皮肤进行拉伸测试，还进行压缩测试。所测试的皮肤样本界定明确，并通过随动片防止周围环境的影响。该装置的尺寸和形状已通过有限元建模进行了优化。
该方法用在不同载荷下预张紧的弹性体进行了测试。结果表明，可以高精度地恢复初始张力。然后在体内对前臂在不同手臂位置进行了测试。结果表明，尽管皮肤在不同手臂位置呈现出非常不同的拉伸行为，但仅在皮肤张力最高时才能清楚地确定初始张力。
展示了身体姿势如何影响测量。提出了一种轻松确定初始张力的创新方法。然而，要将这种皮肤张力测量应用于不同身体部位和身体姿势，还需要进一步测试和改进装置。
