Liu Hongliang, Prot Victorien Emile, Skallerud Bjørn Helge
Biomechanics Division, Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway.
Biomechanics Division, Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway.
J Biomech. 2018 Aug 22;77:107-114. doi: 10.1016/j.jbiomech.2018.06.011. Epub 2018 Jun 27.
Collapse of the soft palate in the upper airway contributes to obstructive sleeping apnea (OSA). In this study, we investigate the influence of the adhesion from the tongue on the soft palate global response. This is achieved using a cohesive zone finite element approach. A traction-separation law is determined to describe the adhesion effect from the surface tension of the lining liquid between the soft palate and the tongue. According to pull-off experimental tests of human lining liquid from the oral surface of the soft palate, the corresponding cohesive properties, including the critical normal traction stress and the failure separation displacement, are obtained. The 3D patient-specific soft palate geometry is accounted for, based on one specific patient's computed tomography (CT) images. The calculation results show that influence of the adhesion from the tongue surface on the global response of the soft palate depends on the length ratio between the cohesive length and the soft palate length. When the length of the cohesive zone is smaller than half of the soft palate length, the adhesion's influence is negligible. When the adhesion length is larger than 70 percent of soft palate length, the adhesion force contributes to preventing the soft palate from collapsing towards to the pharynx wall, i.e. the closing pressure is more negative than in the no adhesion case. These results may provide useful information to the clinical treatment of OSA patients.
上气道中软腭塌陷会导致阻塞性睡眠呼吸暂停（OSA）。在本研究中，我们调查了舌头产生的附着力对软腭整体反应的影响。这是通过使用内聚区有限元方法实现的。确定了一个牵引-分离定律来描述软腭与舌头之间衬液表面张力产生的附着效应。根据从软腭口腔表面提取人体衬液的拉脱实验测试，获得了相应的内聚特性，包括临界法向牵引应力和失效分离位移。基于一名特定患者的计算机断层扫描（CT）图像，考虑了三维患者特异性软腭几何形状。计算结果表明，舌头表面附着力对软腭整体反应的影响取决于内聚长度与软腭长度之间的长度比。当内聚区长度小于软腭长度的一半时，附着力的影响可忽略不计。当附着长度大于软腭长度的70%时，附着力有助于防止软腭向咽壁塌陷，即关闭压力比无附着情况时更负。这些结果可能为OSA患者的临床治疗提供有用信息。
