In vivo characterization of facial soft tissue is of great significance for facial plastic surgery, animation and dermatology. This paper presents an in vivo experimental method to characterize the macroscopic mechanical properties of facial soft tissue. In this method, a bi-layer material (BLM) model is established with the skeleton as the substrate under the facial soft tissue and the relationship between the mechanical properties of soft tissue and force–displacement curve is obtained. A novel indentation apparatus is also developed to experimentally measure the force-displacement curve of the facial soft tissue in vivo. Using the apparatus, experiments were conducted on artificial skins to verify the theoretical model. Experiments on facial soft tissue were finally conducted on four volunteers to obtain Young’s moduli at five facial locations using an optimal indenter whose radius is determined by the verification experiment. Our experiment results indicate that a slight difference is observed in Young’s moduli of facial soft tissue among different volunteers and indentation location. At locations of the left-hand cheek near the lips (NE) and center of the left-hand jaw (CJ), Young’s moduli E1 are relatively large ranging from 2.653kPa to 4.437kPa. Nevertheless, at other locations of the center of the cheek (CC), left-hand zygomatic region (ZYG) and left-hand cheek near the lips (NL), the contact forces are smaller, and Young’s moduli E1 are between 1.649kPa and 3.395kPa.

中文翻译：

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使用双层材料模型在体内测量面部软组织的机械性能

体内面部软组织的表征对于面部整形外科、动画和皮肤科具有重要意义。本文提出了一个体内表征面部软组织宏观力学性能的实验方法。该方法以骨骼为基底，在面部软组织下建立双层材料（BLM）模型，得到软组织力学性能与力-位移曲线的关系。还开发了一种新型压痕装置，用于实验测量面部软组织的力-位移曲线体内. 使用该装置在人造皮肤上进行了实验以验证理论模型。最后对四名志愿者进行面部软组织实验，使用验证实验确定半径的最佳压头获得面部五个位置的杨氏模量。我们的实验结果表明，在不同的志愿者和压痕位置之间观察到面部软组织的杨氏模量略有不同。在靠近嘴唇 (NE) 和左下巴中心 (CJ) 的左脸颊位置，杨氏模量乙1都比较大，范围从 2.653千帕至 4.437千帕。然而，在脸颊中心 (CC)、左颧骨区域 (ZYG) 和靠近嘴唇的左脸颊 (NL) 的其他位置，接触力较小，杨氏模量乙1介于 1.649 之间千帕和 3.395千帕。