Department of Electrical and Computer Engineering, University of British Columbia, 2366 Main Mall, Vancouver BC, V6T 1Z4 Canada.
J Mech Behav Biomed Mater. 2013 Dec;28:484-94. doi: 10.1016/j.jmbbm.2013.03.004. Epub 2013 Mar 15.
Characterising the mechanical properties of human facial skin is a challenging but important endeavour with applications in biomedicine, surgery simulation, forensics, and animation. Many existing computer models of the face are not based on in vivo facial skin deformation data but rather on experiments using in vitro facial skin or other soft tissues. The facial skin of five volunteers was subjected to a rich set of deformations using a micro-robotic device. The force-displacement response was recorded for each deformation. All volunteers' facial skin exhibited a non-linear, anisotropic, and viscoelastic force-displacement response. We propose a finite element model that simulated the experimental deformations with error-of-fits ranging from 11% to 23%. The skin was represented by an Ogden strain energy function and a quasi-linear viscoelastic law. From non-linear optimisation procedures, we determined material parameters and in vivo pre-stresses for the central cheek area of five volunteers and five other facial points on one volunteer. Pre-stresses ranged from 15.9kPa to 89.4kPa.
描述人类面部皮肤的机械性能是一项具有挑战性但很重要的工作，它在生物医学、手术模拟、法医学和动画等领域都有应用。许多现有的面部计算机模型并不是基于体内面部皮肤变形数据，而是基于使用体外面部皮肤或其他软组织进行的实验。使用微型机器人设备对五名志愿者的面部皮肤进行了丰富的变形实验。记录了每种变形的力-位移响应。所有志愿者的面部皮肤都表现出非线性、各向异性和粘弹性的力-位移响应。我们提出了一个有限元模型，该模型可以模拟实验变形，拟合误差在 11%到 23%之间。皮肤由 Ogden 应变能函数和准线性粘弹性定律来表示。通过非线性优化程序，我们确定了五名志愿者的脸颊中部和一名志愿者的另外五个面部点的材料参数和体内预应力度。预应力度范围从 15.9kPa 到 89.4kPa。
