北京生物医学工程
北京生物醫學工程
북경생물의학공정
BEIJING BIOMEDICAL ENGINEERING
2015年
2期
118-124
,共7页
王建霞%安云强%王辉%黄亚奇
王建霞%安雲彊%王輝%黃亞奇
왕건하%안운강%왕휘%황아기
计算流体力学模拟%实体模型%上气道%阻塞性睡眠呼吸暂停
計算流體力學模擬%實體模型%上氣道%阻塞性睡眠呼吸暫停
계산류체역학모의%실체모형%상기도%조새성수면호흡잠정
computational fluid dynamics simulation%physical model%upper airway%obstructive sleep apnea
目的：用计算流体力学模拟的方法和体外模型实验的手段，研究呼吸时真实结构的上气道内的流动状态和压力分布，同时验证数值模拟模型的准确性。方法首先基于磁共振图像，借助 Mimics软件重建上气道三维结构。在此真实几何结构基础上，建立上呼吸道内流动的有限元分析模型，以及制作相应的实体模型。模拟并测量呼吸流量为200、400和600 mL/s时的情况，并将数值模型预测的壁面压力分布与实测结果比较。结果如果气道内气流流量相同，吸气时气道两端的压差比呼气时大，即吸气时气道阻力比呼气时大。不同点压力分布的数值计算结果与实体模型测量结果一致。数值模拟结果表明，吸气时气道悬雍垂以及会厌后的舌后区域流动速度较高，悬雍垂下舌后区有涡旋产生。呼气时矢状位鼻咽顶端靠近后壁处，冠状位鼻咽、会厌下口咽处均有涡旋产生。结论数值模型可以准确地模拟上气道的流动状态和压力分布，直观地反映上气道内流动特点。作为非侵入式的工具，气道模型和数值模拟可以在探索阻塞性睡眠呼吸暂停（ obstructive sleep apnea，OSA）的发病机制和有效治疗方法的过程中发挥重要作用。
目的：用計算流體力學模擬的方法和體外模型實驗的手段，研究呼吸時真實結構的上氣道內的流動狀態和壓力分佈，同時驗證數值模擬模型的準確性。方法首先基于磁共振圖像，藉助 Mimics軟件重建上氣道三維結構。在此真實幾何結構基礎上，建立上呼吸道內流動的有限元分析模型，以及製作相應的實體模型。模擬併測量呼吸流量為200、400和600 mL/s時的情況，併將數值模型預測的壁麵壓力分佈與實測結果比較。結果如果氣道內氣流流量相同，吸氣時氣道兩耑的壓差比呼氣時大，即吸氣時氣道阻力比呼氣時大。不同點壓力分佈的數值計算結果與實體模型測量結果一緻。數值模擬結果錶明，吸氣時氣道懸雍垂以及會厭後的舌後區域流動速度較高，懸雍垂下舌後區有渦鏇產生。呼氣時矢狀位鼻嚥頂耑靠近後壁處，冠狀位鼻嚥、會厭下口嚥處均有渦鏇產生。結論數值模型可以準確地模擬上氣道的流動狀態和壓力分佈，直觀地反映上氣道內流動特點。作為非侵入式的工具，氣道模型和數值模擬可以在探索阻塞性睡眠呼吸暫停（ obstructive sleep apnea，OSA）的髮病機製和有效治療方法的過程中髮揮重要作用。
목적：용계산류체역학모의적방법화체외모형실험적수단，연구호흡시진실결구적상기도내적류동상태화압력분포，동시험증수치모의모형적준학성。방법수선기우자공진도상，차조 Mimics연건중건상기도삼유결구。재차진실궤하결구기출상，건립상호흡도내류동적유한원분석모형，이급제작상응적실체모형。모의병측량호흡류량위200、400화600 mL/s시적정황，병장수치모형예측적벽면압력분포여실측결과비교。결과여과기도내기류류량상동，흡기시기도량단적압차비호기시대，즉흡기시기도조력비호기시대。불동점압력분포적수치계산결과여실체모형측량결과일치。수치모의결과표명，흡기시기도현옹수이급회염후적설후구역류동속도교고，현옹수하설후구유와선산생。호기시시상위비인정단고근후벽처，관상위비인、회염하구인처균유와선산생。결론수치모형가이준학지모의상기도적류동상태화압력분포，직관지반영상기도내류동특점。작위비침입식적공구，기도모형화수치모의가이재탐색조새성수면호흡잠정（ obstructive sleep apnea，OSA）적발병궤제화유효치료방법적과정중발휘중요작용。
Objective The alm of this study was to investigate the flow and pressure distributions in the upper alrway during respiration using computational fluid dynamics methods and in vitro experiments,and to test the accuracy of the numerical models. Methods An anatomically accurate finite element model of the human upper alrway was constructed from magnetic resonance images,and an identical physical model of the same alrway was built. Numerical simulations and experimental measurements were performed at flow rates of 200 ml/s,400 ml/s,and 600 ml/s,and the model-predicted distributions of the wall static pressure were compared with measured results. Results When the flow flux was the same,a larger pressure drop between the two ends of the upper alrway was required during inspiration compared to expiration. That means a larger flow resistance during inspiration compared to expiration. The numerical predictions of the wall pressure at different locations of the upper alrway were consistent with the measured data from the physical model. Numerical results showed high velocities in the retropalatal and retroglossal regions near the epiglottis during inspiration. Vortex flows occurred at the region below the uvula. During expiration, vortex flows could be observed at the region near the posterior top of the nasopharynx wall in the midsagittal plane,and in the nasopharynx and the oropharynx below the uvula in the coronal plane. Conclusions Numerical models can be used to simulate the flow field and pressure distribution accurately,as well as to show the flow characteristics in the upper alrway intuitively. As noninvasive methods,in vitro models and numerical simulations could play an important role in the study on the pathogenesis and effective treatment methods of obstructive sleep apnea.
