鼻中隔穿孔对鼻腔气流场影响的数值模拟研究

Effect of nasal septal perforation on the nasal airflow field

关键词:  穿孔  鼻中隔  气流动力学  鼻腔

Key words:  perforation  nasal septum  airflow fields  nasal cavity

摘要:

目的　 探讨鼻中隔穿孔对鼻腔气流场的影响。方法　对1例健康国人行鼻CT扫描，进一步完成鼻腔气道结构表面三维重建，分别在模型的鼻瓣区、鼻甲前区、鼻腔中部对应鼻中隔部位建立直径10 mm的圆形穿孔，分别设定边界条件并求解黏性流体运动方程和Navier-Stokes方程，分析通气量为12 L/min时的气流场。结果　 穿孔前鼻腔气流场符合正常国人特征；穿孔后吸气和呼气相鼻中隔穿孔区域气流形式紊乱，形成大小、数量不等的漩涡，双侧鼻腔存在10~20 mL/s的气流分流现象，但鼻腔中部对应穿孔区域呼吸两相气流形式不同。结论　 鼻中隔穿孔后穿孔区域形式紊乱，主要表现为大小、数量不等的漩涡，对毗邻气流影响程度不同；鼻腔双侧存在少量气流分流现象。

Abstract:

Objective　To explore the effect of nasal septal perforation at different locations on the nasal airflow field. 　Methods　A three dimensional model throughout human nasal cavity was established based on spiral CT scan data. Furthermore, nasal septal perforations were created in the model at different locations of nasal valve, anterior turbinates and middle nasal cavity in the cylindrical shape with the same diameter of 10 mm. Given three preconditions, the nasal airflow fields were described by the Navier-Stokes and continuity equations at the ventilation volume of 12 L/ min, respectively. The whole airflow patterns were obtained, and then comparing the airflow filed between before and after septal perforations. 　Results　The characteristics of nasal airflow field before septal perforation were in accordance with the healthy Chinese. After septal perforations, the nasal airflow were in disorder in the airway of septal perforations with the mainly airflow pattern of reversals and there were flow exchange via the septal perforations with the velocity of 10-20 mL/s in both inspiratory and expiratory phases. But, the airflow patterns in septal perforation at the location of middle nasal cavity were different between inspiratory and expiratory phases. 　Conclusion　The airflow pattern was in disorder in the airway of septal perforations with the mainly manifestation of reversals, affecting the neighboring airflow to certain extent. And there were small amount of flow exchanges via septal perforations between both sides.