Measurement of blood hematocrit inside the magnetically suspended centrifugal pump using an optical technique: application to assessment of pump flow.
Measurement of blood hematocrit inside the magnetically suspended centrifugal pump using an optical technique: application to assessment of pump flow.
复制标题
使用光学技术测量磁悬浮离心泵内的血细胞比容：应用于评估泵流量。
DOI：
10.1046/j.1525-1594.1999.06388.x
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发表时间：
1999
影响因子：
2.4
通讯作者：
S. Takatani
中科院分区：
文献类型：
--
作者：
T. Kaiwa;T. Mori;T. Kijima;M. Nogawa;C. Nojiri;S. Takatani
为了测量磁悬浮离心泵内的血液红细胞比容，我们使用特殊设计的光学电池进行了前向和后向光散射测量。在前向散射测量中，使用光纤将780 nm的近红外光引导到250微米的间隙区，并使用光电晶体管测量前向散射到探测光纤的光。光强度随红细胞压积的增加呈指数下降至20%左右。由于扩散效应，前向散射法在血细胞比容水平25-45%左右时灵敏度较低。通过使光程长度大于几毫米，可以提高前向散射法在红细胞压积变化方面的灵敏度。然而，在后向散射法中，对于0-50%的红细胞压积变化，获得了更好的灵敏度。当光纤间距小于1mm时，系统将从浅层测量一阶后向散射，而当光纤间距大于几毫米时，系统将主要从较深的层测量漫反射。这两种方法都会产生敏感的光强度变化的生理红细胞压积范围。
To measure blood hematocrit inside the magnetically suspended centrifugal pump, we have performed both forward and backward light scattering measurements using a specially designed optical cell. In the forward scattering measurement, an optical fiber was used to guide the near infrared light at 780 nm into a 250 microns gap region, and the light that forward scattered toward a detector fiber was measured using a phototransistor. The light intensity decreased exponentially with an increase in the hematocrit to around 20%. The forward scattering method suffered from sensitivity at the hematocrit levels around 25-45% due to the diffusion effect. By making the optical path length larger than several millimeters, the sensitivity of the forward scattering method in terms of hematocrit change can be improved. In the back scattering method, however, better sensitivity in terms of hematocrit change from 0-50% was obtained. By making the optical fiber separation distance less than 1 mm, the system will measure the first order back scattering from the shallow layer while, by making the fiber separation distance larger than several millimeters, the system will primarily measure the diffuse reflectance from the deeper layer. Both approaches will yield sensitive optical intensity change in terms of the physiological hematocrit range.