有限元分析法在OSAHS疾病个性化治疗方案中的可行性研究

The feasibility study of finite element analysis in the individualized treatment plan for OSAHS disease

目的通过定量描述呼吸气流流场分布情况,探索有限元分析法在阻塞性睡眠呼吸暂停低通气综合征(OSAHS)疾病诊断、治疗及术后评估中的可行性。方法对1例重症OSAHS患者进行睡眠状态CT检查,将数据以Dicom格式保存后导入Mimics软件进行三维重建,Geomagic软件进行曲面拟合,Pro/e中完成对呼吸道进出口的修改,使用Fluent软件进行仿真计算。结果 1对OSAHS患者上呼吸道数值模拟结果可以看出,手术前流场内压力和速度变化最明显的位置是鼻咽腔,主要位于软腭平面,流场速度为22.91m/s,压力梯度变化最明显处为-186.32Pa。2此患者在计算机模型中模拟咽腔扩宽,主要是软腭平面。在临床中实施的手术方案为悬雍垂腭咽成型术、双侧扁桃体切除术联合双下鼻甲骨折外移术。模拟术后最大气流速度为19.39m/s,压力梯度变化最明显处为-150.9Pa,其发生在会厌上缘位置。结论有限元分析能够初步量化OSAHS患者呼吸道阻塞位点,为患者手术方式的选择及术后效果评估提供比较参数,在临床中具有可行性。

Objective By quantitative description of breathing air flow field distribution, to explore the feasibility of finite element analysis in diagnosis, treatment and postoperative evaluation of obstructive sleep apnea- hypopnca syndrome （OSAHS）. Methods One patient with severe OSAHS was examined with CT in sleep. The data saved in Dicom format were imported with mimics software for three-dimensional reconstruction. Geomagic software was used for surface fitting, and the import and export of respiratory changes were completed in Pro/e. Simulation calculation was made with Fluent software. Results （1） The numerical simulation results of the upper respiratory tract in OSAHS patients showed that beforc the operation, the most obvious site of flow field pressure and spccd changes was thc nasopharyngeal cavity, mainly in thc soft palate plane, with flow velocity of 22.91 m/s and pressure gradient of 186. 32 Pa. @ The patient in the computer model simulation had expanded pharyngeal cavity, mainly the planc of the palate. The clinical bilateral tonsillectomy operation scheme was joint uvula up molding technique. Simulated postoperative maximum air velocity was 19.39 m/s and the most obvious position of pressure gradient in the epiglottis was 150.9 Pa, which occurred on the upper edge of epiglottis. Conclusion Finite clement analysis can preliminarily quantify respiratory tract obstruction sites of OSAHS patients, providing comparison parameters of choosing surgical procedure and postoperative outcome evaluation. It has clinical feasibility.