力學在醫學上之應用─第一部分：以毛細管力分析柴油微粒PM2.5對內皮細胞血液通透率之影響；第二部分：依結構力學進行放射性檢測固定裝置的設計與製作

Medical Applications of Mechanics-Part I:Effect on Vascular Permeability of Endothelial Cells Due to PM2.5 Diesel Particles Using the Analysis of Capillary Forces; Part II: Design and Manufacturing of Immobilization Device for Radioactive Inspection Based on Structural Mechanics

黃翊橙(Yi-Cheng Huang)

指導教授 ： 林柏廷

中原大學/工學院/機械工程研究所/碩士(2015年)

https://doi.org/10.6840/cycu201500521

摘要

第一部分
為了解人體吸入空氣汙染所造成心血管疾病的影響，Chao等在2011年證實PM2.5 空污粒子中有14%為<100 nm微粒子，可能藉由破壞內皮細胞的黏合連接處進入血液循環中。文獻中並無標準方法來量化內皮細胞的通透率， 或達西等單位難以量化通透運輸的擴散現象，及血管壁孔洞開闔大小影響通透率的關係，此外通透率易隨著時間變化，瞬時量測值不易取得。本論文發展出一個標準量化血管通透率的研究方法，以了解空污廢氣粒子造成內皮細胞黏合連接處的破壞和內皮細胞通透性的影響。將不同濃度的PM2.5 柴油微粒加入HUVEC細胞培養液中，使其作用0、24、48、72小時後，利用MTS和Dextran-FITC試劑測量其細胞毒性與細胞通透率，並以毛細管數(Capillary Number; CA)來量化黏滯力對表面張力的相對關係，建立微粒子通過內皮細胞交界處由血液通透至組織的標準量化方法。實驗結果除了顯示微粒子暴露濃度及暴露時間的增加會使細胞通透率上升，也會使血液黏滯性上升、表面張力下降，因此毛細管數會微粒子暴露濃度及暴露時間的增加而上升。本論文使用參數模型擬合細胞毒性及細胞通透性隨微粒子暴露濃度及暴露時間改變的函數關係，根據臨界毛細管數的定義，進而建立微粒子暴露的上限函數。
第二部分
嬰孩在接受放射性檢驗或是治療時的情緒不易控制，操作上的疏忽常造成放射線過度曝露、成像不良、錯誤判斷、嬰孩肢體傷害等不良後果，除了影響嬰孩的發育，也可能增加致癌機率。本論文提出創新嬰孩固定裝置，目的在安穩地限制嬰孩在受診過程中的移動範圍，防止意想不到的瞬間快速運動。此外，此設計也注重嬰孩在被固定時的舒適程度、調整固定位置的方便性、其對於成像清晰度的影響、其對於嬰孩局部器官與肢體的保護程度等問題。本研究使用放射線穿透度高的壓克力材料，製作含多固定孔的基座；用壓克力插銷將活動元件(如固定帶、固定蓋等)穩固地固定至基座上，達到固定嬰孩的目的，使用快速旋轉式插銷與魔鬼氈的固定方式可隨著嬰幼兒身形大小做任意調整，以最快的速度順利完成放射性檢測或治療；以舒適且放射線穿透度高的泡棉材料支撐嬰孩的重量，並使用數值分析軟體評估泡棉墊的支撐能力及固定插銷的固定能力。分析結果說明泡棉墊支撐在50公斤的嬰孩時僅變形14.1397公釐，仍具有足夠支撐力，故能提供嬰孩足夠的舒適度且不會永久變形；固定插銷在20公斤的外力彎曲下，在基座固定處有55.7268MPa的彎曲應力，並未超過材料的降伏強度，故具有安全的固定能力。本論文研發的創新嬰孩固定裝置可以有效避免影像模糊、部位偏移或是假影等問題，避免重新拍攝，減少嬰幼兒曝露在輻射環境下的影響。

關鍵字

PM2.5 柴油微粒 ； 內皮細胞 ； 通透率 ； 毛細管數 ； 放射性檢驗 ； 致癌機率 ； 嬰孩固定裝置 ； 旋轉式固定插銷

並列摘要

Part I
To understand the impact of inhaled air pollution on cardiovascular diseases, Chao et al., in 2011, confirmed that PM2.5 air pollution particles have a 14% chance of containing <100 nm particles that could destroy junction adhesion sites of endothelial cells to blood circulation regions. There is not a standard method to quantify the rate of endothelial cell permeability. The units of or Darcy cannot represent the diffusion phenomenon of permeability at the cell junction and the change of permeability due to opening and closing of the blood vessels. Furthermore, blood to the tissue permeability changes easily over time and it makes difficult to obtain the transient measurement of cell permeability. This thesis has developed a standard methodology to quantify the rate of vascular permeability in order to understand the damage of endothelial junction and the change of endothelial permeability cased by the fine particles in the air pollution. Various concentrations of diesel PM2.5 particles were added to a HUVEC cell culture medium for 0, 24, 48 and 72 hours. Afterward, MTS reagent and Dextran-FITC were used to investigate the cell cytotoxicity and the permeation rates, respectively. In addition, Capillary Number (CA) was used to measure the permeability behavior in terms of viscous force over surface tension in order to build a standardized way to quantify the blood-to-tissue transport phenomena of PM2.5 at the junction between the endothelial cells. The experimental results showed cell permeability increases with the concentration of PM2.5 and exposure time. Moreover, increasing viscosity and decreasing surface tension caused by larger PM2.5 concentration and longer exposure time leading to a higher measure of CA. This thesis parametrically modeled the responses of cell cytotoxicity and CA with respect to PM2.5 concentration and exposure time. A mathematical function was determined to represent the safety region of PM2.5 exposure under the decision of critical CA.
Part II
An infant’s mood when subject to radioactive test or treatment is not easy to control. This often causes negligent operation of the radiographer such as overexposure, poor image, misjudgment, bodily harm to the baby and other adverse consequences. In addition to affecting the baby's development this also increases the risk for cancer in the baby. This paper presents an innovative baby fixture for the purpose of restricting rapid, instantaneous movement in a baby and secures the range of movement during the consultation process. In addition, this design also focuses on baby comfort while being fixed, convenient adjustment to the desired position, effects on the clarity of the image, and the degree of protection of sensitive organs and limbs. In this study, a highly penetrative the acrylic material was used for the fixed base containing fixation holes and acrylic plugs with the active components (such as straps fixed cover, etc.) which can be securely fixed to the base to the baby. A fast rotary fixation design and Velcro fastening means that the size of infants may vary and any adjustments can be easily made which aides in the successful completion of a fast radioactive detection or treatment. To provide more comfort, a highly radiation penetrating foam was added to support the weight of the baby. The use of numerical analysis software was used to assess the fixation device, the supporting foam pad and the pin fixation capacity. The results of the numerical simulations show that the foam pad supporting a 50 kg baby only deformed 14.1397 mm which provides adequate support force. It can provide sufficient comfort for the baby without permanent deformation. The fixation pins subject to a 20 kilograms of downward bending force when fixed at the base is subject to 55.7268MPa bending stress. This stress is less than the yield strength of the material therefore it will not fail. The innovative baby fixation device developed this thesis can effectively avoid image blur, offset, appearance of visual artifacts and other issues which avoids the need to re-shoot, therefore reducing the infant’s exposure to radiation.

並列關鍵字

PM2.5 diesel exhaust particles ； endothelial cells ； viscosity ； surface tension ； permeability ； Capillary number ； radioactive tests ； probability of carcinogenicity ； baby fixation device ； rotary fixation pins

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