Studies on Two-Dimensional Imaging of Oxygen Release from Microvessels.

建立了一种用于测定微血管网络中氧饱和度和流动红细胞含量的二维图像的仪器。(1)仪器由倒置显微镜、摄像机、6个不同波长的干涉滤光片、图像处理器和计算机组成。基于红细胞中氧合血红蛋白和脱氧血红蛋白吸收光谱的差异，制备了微血管中流动红细胞的氧饱和度和含量的二维图像，并制备了微血管横截面剖面。(2)本仪器可在（血细胞比容%）x（内径mm） <4.5范围内进行定量测定，因此可测定所有向组织释放氧气的微血管。测量精度<正负10%。(3)对微空网络中小动脉向小静脉流动过程中红细胞氧饱和度的降低进行成像。同时成像红细胞轴向积聚，沿血管壁形成无细胞层，窄微血管中的法氏效应和毛细血管中的反法氏效应。(4)随着微血管内红细胞流速的降低和组织内酸性pH的升高，流动红细胞的氧释放加快。(5)红细胞流变特性（红细胞压积、红细胞变形和红细胞聚集）与红细胞流动动力学（以无细胞层厚度评价）和流动阻力（与血管弹性有关）之间的关系进行定量评价。(6)在反射光谱分析的基础上，对脑表面微血管内红细胞的氧饱和度进行了成像。提出了几个有待进一步研究的问题

An apparatus for the determination of two-dimensional images of oxygen saturation and content of flowing erythrocytes in microvascular network was constructed. (1) The apparatus was composed of an inverted microscope, a video-camera, six interference filters with different wavelength, an image processor and a computer. Based on the difference of absorption spectra of oxygenated and deoxygenated hemoglobin in erythrocytes, the two-dimensional images of oxygen saturation and content of flowing erythrocytes in microvessels were prepared, and the profiles in a crossection of microvessels was also prepared. (2) The quantitative determination using the present apparatus was possible in the range of (hematocrit in %) x (inner diameter in mm) <4.5, thus for all microvessels releasing oxygen to tissues. The accuracy of the measurement was <plus-minus>10%. (3) The decrease of oxygen saturation of erythrocytes in the flow process from arterioles to venules in a microvacular network was imaged. The axial accumulation of erythrocytes, thus the formation of cell-free layr along vessel wall, the Fahraeus effect in narrower microvessels and the inverse Fahraeus effect in capillaires were simultaneously imaged. (4) With the decrease of flow velocity of erythrocytes in microvessels and in acidic pH in the tissues, the oxygen release from flowing erythrocytes was accelerated. (5) The relationship between the rheological properties of erythrocytes (hematocrit, erythrocyte deformation and erythrocyte aggregation) and the flow dynamics of erythrocytes evaluated by the thickness of cell-free layr and the flow resistance was quantitatively evaluated in relation with vascular elasticity. (6) Based on the analysis of reflection spectrum, the oxygen saturation of erythrocytes in microvessels on the surface of brain was also imaged. (7) Several problems for further studies were propose