ACCOUNTING FOR NATURAL TENSION IN MECHANICAL TESTING OF HUMAN-SKIN
ACCOUNTING FOR NATURAL TENSION IN MECHANICAL TESTING OF HUMAN-SKIN
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DOI：
10.1111/1523-1747.ep12507731
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发表时间：
1977-01-01
影响因子：
6.5
通讯作者：
COOK, TH
中科院分区：
文献类型：
--
作者：
ALEXANDER, H;COOK, TH
此前，人们使用低压吸力装置来获取人体皮肤机械性能的定量信息。由于皮肤在自然状态下已经是双向加载的事实，减少这项技术的原始数据是复杂的，并且没有合理的基础来比较从不同受试者获得的结果。利用应变测量预拉伸装置，开发了一种确定皮肤中自然状态张力场和延伸场的方法。然后沿测试方向放松自然张力，并使用吸力装置来确定恒定测试速率下皮肤的二维皮肤拉伸-伸长比响应。来自多个受试者的数据被用来发展一个新的多维应力-应变理论，该理论涉及两个材料常数，这两个材料常数与真皮的基本材料特性有关，并且无论自然状态应力场如何，都是唯一可确定的。对23名健康成年男性的上背部进行了测试，以调查材料常数随年龄和阳光暴露习惯的变化。年龄的差异被发现证实了早期的研究，而阳光暴露习惯的变化与已知的由于紫外线辐射引起的真皮胶原和弹性蛋白的变化有关。测试程序对生理状态变量的明显敏感性表明，力学性能表征将成为评估某些病理状态的严重程度和治疗效果的有用工具。
A low-pressure suction device was previously used to obtain quantitative information on mechanical properties of human skin. Reducing raw data from this technique was complicated by the fact that the skin was already biaxially loaded in the natural state, and a rational basis on which to compare results obtained from different subjects was not available. Using a strain gauged pretension device, a procedure for determining the natural state tension and extension fields in the skin was developed. The natural tension was then relaxed in the direction of testing and the suction device used to determine the 2-dimensional skin tension-extension ratio response of the skin at a constant testing rate. Data from a number of subjects were used to develop a new multidimensional stress-strain theory in terms of 2 material constants that were related to basic material characteristics of the dermis and were uniquely determinable regardless of the natural state stress field. Tests performed on upper backs of 23 healthy adult males were used to investigate variations in material constants with age and sun-exposure habits. Age variations were found to corroborate earlier studies, and variations with sun exposure habits were related to known dermal collagen and elastin changes due to ultraviolet radiation. The apparent sensitivity of the testing procedure to physiologic state variables held out the hope that mechanical properties characterization would be a useful tool in evaluation of the severity of certain pathologic states and effect of therapy.