Azarnoosh Jamasp, Hassanipour Fatemeh
Department of Mechanical Engineering, The University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX 75080, USA.
Department of Mechanical Engineering, The University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX 75080, USA.
J Biomech. 2020 Apr 16;103:109640. doi: 10.1016/j.jbiomech.2020.109640. Epub 2020 Jan 21.
There are two theories for the dynamics of milk expression by the infant. One hypothesis is that milk expression is due to the negative pressure applied by the infant sucking; the alternative hypothesis is that the tongue movement and squeezing of nipple/areola due to mouthing is responsible for the extraction of milk from the nipple. In this study, 3-D two-way Fluid-Structure Interaction (FSI) simulations are conducted to investigate the factors that play the primary role in expressing milk from the nipple. The models include the solid deformation and periodic motion of the tongue and jaw movement. To obtain the boundary conditions, ultrasound images of the oral cavity and motion of the tongue movement during breastfeeding are extracted in parallel to the intra-oral vacuum pressure. The numerical results are cross-validated with clinical data. The results show that, while vacuum pressure plays an important role in the amount of milk removal, the tongue/jaw movement is essential for facilitating this procedure by decreasing the shear stress within the main duct in the nipple. The developed model can contribute to a better understanding of breastfeeding complications due to infant or breast abnormalities and for the design of medical devices such as breast pumps and artificial teats.
关于婴儿挤奶的动力学有两种理论。一种假设是，挤奶是由于婴儿吸吮施加的负压所致；另一种假设是，由于婴儿用口含住乳头/乳晕时舌头的运动和挤压导致从乳头中挤出乳汁。在本研究中，进行了三维双向流固耦合（FSI）模拟，以研究在从乳头挤出乳汁过程中起主要作用的因素。模型包括舌头的固体变形、周期性运动以及下颌运动。为了获得边界条件，在获取口腔内真空压力的同时，提取母乳喂养期间口腔的超声图像和舌头运动情况。数值结果与临床数据进行交叉验证。结果表明，虽然真空压力在乳汁排出量方面起着重要作用，但舌头/下颌运动对于通过降低乳头主导管内的剪应力来促进这一过程至关重要。所开发的模型有助于更好地理解因婴儿或乳房异常导致的母乳喂养并发症，并有助于设计诸如吸奶器和人工奶嘴等医疗设备。
