国人上呼吸道系统生物力学模型研究与临床应用

发布时间：2018-04-21 05:30

本文选题：上呼吸道 + 生物力学模型　；参考：《大连理工大学》2012年博士论文

【摘要】：睡眠呼吸障碍性疾病与上呼吸道结构性狭窄密切相关,由于发病率高、危害严重,已成为一个突出的医疗与公共卫生问题,其中以阻塞性睡眠呼吸暂停低通气综合征(Obstructive sleep apnea/hypopnea syndrome, OSAHS)的危害最大。要深刻认知这类与上呼吸道结构异常相关的疾患,需对气道解剖结构与功能之间的交互关系进行定量分析。然而,由于患者的个体差异性和上呼吸道结构形态异常的多样性,给这方面的研究带来了困难。本文针对OSAHS的发病机制和个性化诊疗等临床研究中急需解决的问题,基于计算流体动力学(Computational fluid dynamics, CFD)和流固耦合(Fluid structure interaction, FSI)方法,开展上呼吸道系统生物力学模型的研究,并采集临床观测数据来验证分析方法的可行性和结果的可信性,为深入了解与疾病相关的气道结构与功能的关系,提供了数值量化分析的平台。主要内容包括： 1.根据健康志愿者多层螺旋CT影像学资料,构造较大样本的上呼吸道三维模型。研究四种湍流模型对上呼吸道气流特性的影响,并将得到的计算结果与文献报道的实验和数值模拟数据进行比较,验证本文分析方法的可行性和计算结果的可信性。通过16例健康志愿者上呼吸道气体动力学特性的分析,总结正常气道内气流分布的规律,为进行结构异常的上呼吸道生物力学特性研究奠定基础。 2.针对成人和儿童患者几种典型的手术治疗方案,对手术前后上呼吸道内气流的速度、压强和气道阻力的变化进行定量分析。通过与临床诊断OSAHS的金标准一多导睡眠监测仪(Polysomnograph, PSG)和儿童常规的鼻咽声反射(Acoustic rhinometryAR)的结果进行对比,验证了数值模拟的结果对疗效评估的可靠性。上呼吸道生物力学特性的数值模拟研究能获得常规临床检查无法测得的量化参数,为术式的优选和疗效的评估提供参考依据。 3.对3例伴有鼻阻塞的OSAHS患者行鼻腔结构矫正手术前后上呼吸道的气流特性与软腭的运动姿态进行对比分析,为研究鼻腔结构在OSAHS发病机制中的作用,以及鼻部手术对OSAHS的治疗效果提供定量的依据。数值模拟结果发现,鼻腔结构的矫正与容积的扩大缓解了两例轻度患者上呼吸道的阻塞情况。但对另一例重度患者,尽管术后鼻阻塞的情况得以缓解,但整个上呼吸道气流的速度、压强降和软腭的位移均高于术前,尤其是腭咽区负压的增大对病情的缓解不利。根据获得的力学参数对上呼吸道通气功能进行评估,与PSG的判定和患者的主诉相一致。由于人上呼吸道结构的个体差异性,以及气道结构与气流环境之间复杂的自适应关系,对于不同的上呼吸道结构,鼻阻塞的减轻对整个上呼吸道阻塞情况的影响各不相同。提示临床医生在制定手术方案时,务必对上呼吸道上(鼻腔)、下部分(咽和喉)的一致性和复杂的相关性进行个性化的综合考量。 4.为全面了解OSAHS的发病机理及其与呼吸系统疾病的内在联系,进行异常气道结构对上呼吸道、气管和各级支气管内气流特性影响的研究。由于OSAHS患者腭咽腔的狭窄,使得气管和各级支气管内气流的速度和压强降均高于正常气道。受支气管结构异常的影响,除气管和各级支气管的气流结构发生明显变化之外,上呼吸道的压强降有所升高,尤其在呼气相。此外,分析不同呼吸路线(鼻腔呼吸、鼻腔与口腔共同呼吸作用)对气流结构的影响,揭示张口呼吸加重气道塌陷和阻塞的原因。大量气流经由口腔吸入和呼出时,会导致气道阻力的重新分配,鼻腔阻力大幅降低,而口腔及其以下气道的阻力反而增大。
[Abstract]:Sleep breathing disorders are closely related to structural stenosis of the upper respiratory tract. Because of the high incidence and severity of the disease, it has become a prominent medical and public health problem, among which Obstructive sleep apnea/hypopnea syndrome (OSAHS) is the most harmful. A quantitative analysis of the interrelationship between the anatomical structure and function of the airway needs a quantitative analysis of the abnormal structure of the upper respiratory tract. However, the diversity of the individual and the abnormal structure of the upper respiratory tract has brought difficulties to this study. This article is aimed at the clinical study of the pathogenesis of OSAHS and the individualized diagnosis and treatment. In urgent need to solve the problem, based on the Computational fluid dynamics (CFD) and the fluid solid coupling (Fluid structure interaction, FSI), the study of the biomechanics model of the upper respiratory system is carried out, and the clinical observation data are collected to verify the feasibility and the credibility of the analytical method, so as to understand the disease and the disease in depth. The relationship between disease related airway structure and function provides a platform for numerical quantitative analysis.
1. based on the multi-slice spiral CT imaging data of healthy volunteers, a three-dimensional model of the upper respiratory tract was constructed. The effects of the four turbulence models on the airflow characteristics of the upper respiratory tract were studied. The results were compared with the experimental and numerical simulation data reported in the literature, and the feasibility and results of the analysis were verified and calculated. By analyzing the aerodynamic characteristics of the upper respiratory tract in 16 healthy volunteers, the distribution of airflow in the normal airway was summarized, which laid the foundation for the study of the biomechanical characteristics of the upper respiratory tract with structural abnormalities.
2. for several typical surgical treatments for adults and children, quantitative analysis of the changes in velocity, pressure, and airway resistance in the upper respiratory tract before and after the operation. Through the gold standard Polysomnograph (PSG) and children's conventional nasopharyngeal reflex (Acoustic rhinometryAR) through the clinical diagnosis of OSAHS The results are compared to verify the reliability of the results of the numerical simulation. The numerical simulation of the biomechanical characteristics of the upper respiratory tract can obtain the quantitative parameters that can not be measured in the routine clinical examination, and provide a reference for the optimization of the surgical procedure and the evaluation of the curative effect.
3. in 3 cases of OSAHS patients with nasal obstruction, the airflow characteristics of the upper respiratory tract were compared with the motion posture of the soft palate before and after the nasal structure correction, in order to study the role of the nasal cavity in the pathogenesis of OSAHS, and to provide a quantitative basis for the effect of nasal surgery on the treatment of OSAHS. The enlargement of correction and volume relieved the obstruction of the upper respiratory tract in two mild patients. But for another severe patient, although the postoperative nasal obstruction was relieved, the velocity, pressure drop and the displacement of the soft palate were all higher than that before the operation, especially the increase of the negative pressure in the palatyngeal region. The mechanical parameters of the upper respiratory tract were evaluated, consistent with the decision of the PSG and the patients' complaints. Due to the individual differences in the upper respiratory tract structure, and the complex adaptive relationship between the airway structure and the air flow environment, the reduction of the nasal obstruction to the whole upper respiratory tract for the different upper respiratory tract structures The effects are different. It is necessary for clinicians to make an individualized and comprehensive consideration of the consistency and complex correlation of the upper respiratory (nasal cavity) and the lower part (pharynx and larynx) in the formulation of the surgical plan.
4. in order to fully understand the pathogenesis of OSAHS and its internal relationship with respiratory diseases, study the influence of abnormal airway structure on the characteristics of upper airway, trachea and bronchial air flow. Because of the stenosis of the palatopharyngopharynx in OSAHS patients, the velocity and pressure drop of the trachea and all levels of endobronchial air are higher than that of the normal airway. The influence of abnormal airway structure, in addition to the obvious changes in the airflow structure of the trachea and the bronchial tube, the pressure drop of the upper respiratory tract increased, especially in the expiratory phase. In addition, the influence of different breathing routes (nasal respiration, nasal cavity and oral respiration) on the airflow structure was analyzed, and the aggravated airway collapse and obstruction of the mouth breathing were revealed. The cause of the plug. When a large number of airflows are inhaled and exhaled through the mouth, the airway resistance is redistributed, and the resistance of the nasal cavity is greatly reduced, and the resistance of the oral cavity and the following airway is increased.

【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R318.01

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