微血管內血球濃度變化對流阻之影響

血液黏度增加是產生高血壓和動脈硬化發病及死亡率的一個因素，這是因為黏度增加會產生組織局部性缺血。在此我們研究細胞可變形性對血液中黏度，血管壓力，和生理改變的影響。影響紅血球細胞有三個重要因素：(a)紅血球細胞的血比容-紅血球細胞的血比容增加，懸浮液黏度增加。(b)細胞可變形性-紅血球細胞可變形性降低，懸浮液黏度增加。(c)紅血球細胞聚集性-紅血球細胞的聚集造成血液的黏度增加。紅血球變形且向軸心集中是過去常被研究的課題，在此針對此課題作更深入探討。本文中以Snabre-Mills流變模型作為主要研究工具，其主要理論是當顆粒變形時會導致最大充填濃度增加。該流變模型具有相當的理論基礎，因此可以解釋巨觀流體行為與微觀顆粒性質的關係。研究結果顯示軸心集中可使阻力變小直到軸心紅血球密度接近最大充填濃度。另外可發現血流由小動脈進入微血管時，血流變形量與管徑有關。

關鍵字

流變模型；最大充填濃度

並列摘要

Increase in blood viscosity is one factor in hypertension and atherosclerosis that contributes to the morbidity and mortality associated with tissue ischemia. In this research we evaluated the effect of blood deformability on viscosity, blood pressure, and physiology. The RBC suspensions is strongly influenced by the following three factors: (a) volume fraction of RBC—with the increase in the volume fraction of RBC, the suspension viscosity increases; (b) cell deformability—the suspension viscosity increases with the decrease in RBC deformability; and (c) aggregation of RBCs—Aggregation of RBCs results in an increase in the viscosity of blood. Axial migration of RBCs has been extensively studied in the past.In this paper, this subject is studied with Snabre-Mills rheological model, which assumes that cellular deformability would lead to the increase of the maximal packing density. This theoretically derived rheological model can provide valuable information regarding the connection between macroscopic flow behavior and microscopic particle properties. Simulation results show the increase of the degree of axial migration results in the lower flow resistance. Another result shows that when the blood flow entering smaller capillaries, the red cells undergo less deformation.

並列關鍵字

rheological model ； maximum packing concentration

參考文獻

[1] Chen X. B., Schoenau G., and Zhang W. J., “Modeling of time-pressure fluid dispensing process,” IEEE Trans. Electron. Packag. Manufact., Oct. 2000, vol. 23, pp. 300-305.

[2] Tattersall G.H., Banfill P.F.G., “The rheology of fresh concrete.”, Boston Pitman Books, 1983, pp xii, 356.

[3] Peressini, D., Sensidoni, A., Bruno de Cindio., “Rheological characterization of traditional and light mayonnaises.” J. Food Eng., 35, 1998, pp.409-417.

[4] Barbosa Canovas G. V., Peleg M., “Flow parameters of selected commercial semi-liquid food products.” J. Texture Stud., 14, 1983,pp. 213-234.

[5] Taletunc-Gencer, G., Peleg M., “Digitizer aided determination of yield stress in semi-liquid foods”, J. Food Sci., 49, 1984,pp. 1620-1621.

國際替代計量

微血管內血球濃度變化對流阻之影響

全文下載

主題瀏覽