上气道及部分支气管生物力学模型的数值研究

目的建立上气道、气管及部分支气管的生物力学模型,研究不同呼吸模式对气道内气流特性以及气道阻力的影响。方法根据CT扫描资料,建立包括鼻腔、口腔、咽、喉、气管和部分支气管在内的具有真实解剖结构形态的三维有限元呼吸道模型,针对现实中几种典型情况,数值模拟流经鼻、口的气流不同比例情况下气道内的气流特性。结果当仅有少量气流经由口腔吸入时,呼吸道内气流的分布规律以及各部位气道阻力的大小与完全经由鼻腔呼吸的情况相似。当口腔吸入或呼出大量气体,气流主要经由口腔与外界进行交换时,呼吸道内气流场、压力场和剪应力场分布规律明显不同,主要区别体现在鼻腔、口腔气道内。结论建立上气道与气管、支气管生物力学模型,可以从整体上了解呼吸过程中整个上气道至部分支气管中气流的分布情况,为了解与上气道结构相关疾病的发病机制建立数值研究平台。

Numerical study on biomechanical model of the upper airway and part of bronchus

Objective To establish the biomechanical model of the upper airway, trachea and part of bronchus, and study the influences of different breathing modes on flow characteristics and airway resistance. Methods Based on data of CT scans, three-dimensional finite element model of an anatomically accurate upper airway was established, including the nasal cavity, oral cavity, pharynx, larynx, trachea and part of bronchus. According to several typical cases in reality, numerical simulations were performed on airflow characteristics in upper airway with different proportion of oral airflow and nasal airflow. Results When only a small amount of airflow was inhaled from the mouth, the distribution of airflow characteristics and the airway resistance were similar to the case of nasal inhalation. When a large amount of airflow was inhaled or exhaled through the mouth, the distribution of airflow, pressure and shear stress changed significantly in the respiratory tract. The main differences were observed in the nasal cavity and the oral cavity. Conclusions Establishing the biomechanical model of the upper airway, trachea and part of bronchus is helpful to understand airflow distributions in the entire upper airway and part of bronchus during respiration and to build the platform of numerical research on pathogenesis of upper airway structure-related diseases.