Nicosia Mark A
Department of Mechanical Engineering, Widener University, One University Place, Chester, PA 19013, USA.
Comput Biol Med. 2007 Oct;37(10):1472-8. doi: 10.1016/j.compbiomed.2007.01.007. Epub 2007 Mar 19.
As individuals age, one of the objective changes that occurs in the oropharyngeal swallow is the development of a delay between bolus entry into the pharynx and the initiation of airway protection mechanisms. For longer delays, this phenomenon is sometimes referred to as "premature spillage," and it has been suggested that such spillage, which is a risk factor for dysphagia, may be associated with pre-swallow lingual gestures, or "tongue pumping." The goal of the current study was to develop a simplified two-dimensional computational model of the oropharynx to simulate the containment of a Newtonian fluid bolus within the oral cavity in response to a given pattern of lingual gestures for different viscosities. An arbitrary Lagrangian-Eulerian simulation was performed using the commercial finite element software package, LS-Dyna. It was found that for a given lingual motion, higher viscosity Newtonian boluses, consistent with those offered therapeutically, were able to be contained within the simulated oral cavity while a lower viscosity bolus would be "spilled," suggesting a potential mechanisim by which thickened liquids may reduce aspiration. Although the current data must be validated with more realistic, three-dimensional geometric information and for a wider range of bolus rheologies, they represent an exciting first step towards realistic modeling of oropharyngeal bolus flow.
随着个体年龄的增长，口咽吞咽中出现的一个客观变化是食团进入咽部与气道保护机制启动之间出现延迟。对于较长的延迟，这种现象有时被称为“过早溢出”，有人认为这种溢出作为吞咽困难的一个风险因素，可能与吞咽前的舌部动作，即“舌泵作用”有关。本研究的目的是建立一个简化的口咽二维计算模型，以模拟在不同粘度下，针对给定的舌部动作模式，牛顿流体食团在口腔内的容纳情况。使用商业有限元软件包LS-Dyna进行了任意拉格朗日-欧拉模拟。结果发现，对于给定的舌部运动，与治疗中使用的食团粘度一致的较高粘度牛顿食团能够被容纳在模拟口腔内，而较低粘度的食团则会“溢出”，这表明了浓稠液体可能减少误吸的一种潜在机制。尽管目前的数据必须用更真实的三维几何信息以及更广泛的食团流变学进行验证，但它们代表了朝着口咽食团流动的真实建模迈出的令人兴奋的第一步。
