睡眠呼吸中止症虛擬手術之肌肉組織特性與手術後呼吸道擴張流場分析

Virtual surgery and simulation analyses on human upper airway of obstructive sleep apnea patients

張丹怡(Tan-yi Chang)

指導教授 ： 劉通敏

國立清華大學/工學院/動力機械工程學系/碩士(2015年)

摘要

本文利用數值計算方法，模擬睡眠呼吸中止症患者之肌肉組織特性，並於特定範圍之身體質量指數(Body Mass Index， BMI)下，歸納出一組肌肉材料係數，藉此估計患者手術後之呼吸道擴張情形，以提供醫生手術前之評估參考。
首先，蒐集3位BMI相近(20.5、22.9、23.1)患者於手術前後之電腦斷層掃描(Computed Tomography，CT)影像，分別重建出手術前後的下頷骨、呼吸道，下頷及頸部之肌肉組織與外型。再利用固體力學計算模擬手術後情形，稱之為虛擬手術方法，並將肌肉材料性質假設為彈性(elasticity)、非等向性(anisotropy)及均質材料(homogeneous materials)；將病患於臨床手術前、臨床手術後與虛擬手術後3種時期之上呼吸道以計算流體力學進行吸氣模擬，採用k-ω SST紊流模式及正常人吸氣量Q=5×〖10〗^(-4) m^3/s為入口條件，比較此3種時期上呼吸道之窄縮率、吸氣壓差、最小截面積處之壁剪應力的異同，進而判斷虛擬手術方法之可靠性。在研究中發現患病診斷標準的新參數──噴流擴張角(turbulence jet angle)，經過手術後的呼吸道其噴流擴張角會大幅降低，相較於手術前呼吸道之噴流擴張角小於40%以上。
本研究最後歸納出一組在21

關鍵字

呼吸中止症 ； 上呼吸道重建 ； 流場模擬 ； 虛擬手術

並列摘要

Numerical method is employed to simulate the muscle material characteristics of obstructive sleep apnea (OSA) patients. A set of averaged muscle material characteristics for the range of body mass index (BMI) examined is concluded to predict the expansion of the patient’s upper airway after surgery for the clinic reference before the surgery. Firstly, the mandibular bone, chin, neck and upper airway models of three patients, whose BMI are similar, are reconstructed based on the computed tomography (CT) images before and after surgery. Then, the model structures before and after “virtual surgery” are simulated by computational solid mechanics (CSM) with the assumptions of elasticity, anisotropy and homogeneous muscle material characteristics. Iterations are subsequently performed through comparing the model outlines obtained by “virtual surgery” simulation and the clinical surgery to acquire the appropriate muscle material characteristics of patients. A set of proper muscle material characteristics of patients is thus attained for 21

並列關鍵字

Obstructive Sleep Apnea ； airway reconstruction ； virtual surgery ； muscle material characteristics ； CFD and solid mechanics simulations ； upper airway narrow rate and total inhaling pressure drop

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