成人OSAHS手术前后鼻、咽腔及软腭的流固耦合数值分析

发布时间：2018-04-03 18:40

本文选题：阻塞性睡眠呼吸暂停　切入点：鼻腔结构矫正术　出处：《大连医科大学》2011年硕士论文

【摘要】：目的:应用多导睡眠呼吸监测(polysomnogram,PSG)和三维有限元数值模拟研究成人阻塞性睡眠呼吸暂停低通气综合症(obstructive sleep apnea-hypopnea syndrome,OSAHS)患者经鼻腔结构矫正术后的疗效和鼻、咽腔及软腭流固耦合数值模拟的变化特征。方法:应用多导睡眠呼吸监测对4例成人OSAHS患者进行鼻腔结构矫正术术前检测和术后3-5个月的复查;并对其中3例患者进行术前及术后5个月上气道及周围组织的CT扫描,将所得的3例患者术前、术后的影像学数据导入mimics软件中建立人上气道及软腭的三维模型,应用ansys有限元分析软件建立3例术前、术后的三维有限元模型,应用流固耦合的方法研究上气道流场与软腭运动的相互作用,分析成人OSAHS患者术前、术后上气道流场和软腭固体场的变化特征。结果: 1.多导睡眠呼吸监测(PSG): 病例1、2术后3-5个月AHI由术前的轻-中度转变为单纯性鼾症,术后睡眠时呼吸暂停、低通气等相关症状基本消失,疗效为治愈;病例3、4术后5个月AHI分别降低了24.7%和9%,OSAHS症状均无明显好转,疗效为轻度好转。 2.三维重建模型的测量:3例患者术后鼻腔气道较术前明显增宽。 3.流固耦合数值模拟结果: 压强场:病例1、2术前在吸气期两侧鼻腔压强分布趋势不同,前鼻孔至中鼻道前端的压强差偏曲侧较对侧大且压强梯度变化较为急剧;病例3在术前吸气期两侧鼻腔的压强分布趋势较相似,但不同于正常鼻腔。术后3例患者两侧鼻腔压强分布趋势和压强差值均较为相似,且主要的压强差集中在鼻阈区附近,前鼻孔至鼻咽部压强差较术前减小。流速场:病例1、2术后软腭后区气流的最大流速较术前降低;病例3术后软腭后区的最大流速较术前有所增大。壁面剪切力:病例1术前、术后在上气道均出现三个较高的壁面剪切力区:鼻阈区附近、腭咽区附近、声门区附近,但术后壁面剪切力值均较术前减小,腭咽区附近壁面剪切力的变化趋势减缓;术前两侧鼻腔壁面剪切力的分布趋势不同,术后则较为相似;病例3术前上气道出现三个高壁面剪切力区:鼻阈后至中鼻道前端的区域、腭咽区附近、声门区附近,最高壁面剪切力出现在腭咽区附近;术后仅在腭咽区附近出现较高的壁面剪切力,且数值较术前增大。软腭位移场:术后病例1、2悬雍垂尖部位移较术前减小;病例3悬雍垂尖部较术前有所增大。结论: 1.经本研究,认为以鼻腔结构异常为主要阻塞平面的OSAHS病人(包括腺样体肥大),手术处理鼻腔阻塞平面,扩大鼻腔气道容积,是去除鼻腔阻塞平面,治疗OSAHS的有效方法。 2.对于上气道存在多个阻塞平面,即鼻、咽平面、口咽部软腭区平面等,类如病例3、4,手术后鼻腔气道增宽,在治疗鼻阻塞平面是有效的。但根据气道空气流动特点,鼻腔气道越“通畅”,有可能更增加软腭区压力差,促使软腭运动幅度增大,对治疗OSAHS不利,其治疗方案还需完善。 3.通过有限元数值模拟结合临床多导睡眠呼吸监测的方法来研究OSAHS阻塞平面,并进行术前个性化评估对其治疗方案的选择和疗效评估是必要的;其可以为临床提供定量的、可分析的平台,是一种有效的、值得推荐和深入探讨的研究方法。因本组病例较少,有待进一步扩大样本深入研究,得出更具说服力的结果。
[Abstract]:Objective: using polysomnography (polysomnogram, PSG) and three dimensional finite element numerical simulation study of adult obstructive sleep apnea hypopnea syndrome (obstructive sleep apnea-hypopnea syndrome, OSAHS) in patients with curative effect and postoperative correction of nasal cavity structure, change characteristics of pharynx cavity and soft palate of FSI numerical simulation.
Methods: using polysomnography in 4 adult patients with OSAHS underwent nasal structure correction of preoperative examination and postoperative 3-5 months; and the CT scan 5 months of upper airway and surrounding tissues in 3 patients before and after surgery, 3 cases of patients were obtained before. After images of the upper airway and the soft palate to establish 3D model data into Mimics software, using ANSYS finite element analysis software to establish 3 cases of preoperative, postoperative three-dimensional finite element model, the interaction method of coupling the upper airway flow and soft palate movement by flow, analysis of adult OSAHS patients after the operation, the upper airway flow and soft palate solid field change characteristics.
Result:
1. polysomnography (PSG):
Case 3-5 months after 1,2 AHI from mild to moderate changes before surgery for simple snoring, postoperative sleep apnea, hypopnea and other related symptoms disappeared, the curative effect to cure cases; 3,4 AHI 5 months after operation were decreased by 24.7% and 9% OSAHS, there is no obvious improvement of symptoms, curative effect is slightly improved.
2. measurement of 3D reconstruction model: 3 cases of patients with postoperative nasal airway significantly widened.
3. FSI numerical simulation results:
The pressure field in 1,2: a case of preoperative inspiratory phase sides nasal cavity pressure distribution trend of different pressure, anterior nostril to the nasal passage in front of the poor than the deviation side changes and pressure gradient on the side sharply; 3 cases in the preoperative inspiratory phase of both sides of the nasal pressure distribution trend is similar, but different from that of normal nasal cavity after operation. 3 cases of patients with nasal cavity pressure distribution trend and the pressure difference are relatively similar, and mainly concentrated in the vicinity of the pressure difference between the nasal valve area, anterior nostril to the nasopharynx pressure difference was decreased.
The velocity field: a case after 1,2 the maximum velocity of soft palate airflow decreased after operation in 3 cases; the maximum velocity of the soft palate than before surgery has increased.
The wall shear stress: 1 cases before surgery, after surgery in the upper airway appeared three high wall shear stress zone near the nasal valve area, near the velopharyngeal area, glottic area nearby, but after the wall shear stress values were decreased, the change trend of slowing down near the velopharyngeal area wall shear stress; distribution of preoperative nasal wall on both sides of shear force, after the operation are similar; 3 cases of preoperative airway appeared on the three high wall shear stress zone: regional front to the nasal meatus threshold, the velopharyngeal area near the glottic region near the maximum wall shear stress in near the velopharyngeal area; postoperative only near the velopharyngeal area high wall shear stress, and the value is increased compared with pre operation.
The displacement field of soft palate: postoperative cases 1,2 uvula apex shift was decreased; 3 cases of the tip of the uvula than before surgery has increased.
Conclusion:
1. by this study, that the abnormal nasal structure as the main obstruction plane of OSAHS patients (including adenoid hypertrophy), surgical treatment of nasal obstruction plane, expanding the volume of nasal airway, removing nasal obstruction plane, effective method for the treatment of OSAHS.
2. for multiple upper airway obstruction plane, nose, throat plane, the velopharyngeal plane, such as case 3,4, postoperative nasal airway is widened, in the treatment of nasal obstruction plane is effective. But according to the characteristics of nasal airway airway air flow, more "smooth", there may be more to increase the area of the soft palate the pressure difference, the movement range of the soft palate increased, the treatment of OSAHS is negative, the treatment needs to improve.
3. numerical simulation by finite element method combined with clinical polysomnography to study OSAHS obstruction plane, and preoperative personalized assessment for the choice of treatment and the curative effect is necessary; it can provide quantitative analysis for clinical, the platform is an effective, worthy of recommendation and research methods further discussion. Because of this group of patients is less, further expand the research sample, draw more convincing results.

【学位授予单位】：大连医科大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R766

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