Development of laser speckle retinal vessels for measuring system

点击翻译按钮获取中文摘要

We developed an laser speckle velocimeter in which the laser speckle phenomenon was applied to the measurement of the blood flow velocity in human retinal vessels. A linear relationship between the actual blood flow velocities in glass capillary tubes and the Measured values. In an experiment in which we measured the blood flow velocities of 173 human retinal veins (of which diameter ranged from 62 mum to 186 mum) in 28 eyes of 16 normal volunteers, the blood flow velocities ranged from 1.48 mm/s to 32.5 mm/s. Concerning the relationship between the vessel diameter (D) and the blood flow velocity (V) and blood flow rate (F), linear regression analysis of the measured data showed that logV=[0.49*0.08logD+[0.07*0.16 and logF= [2.49*0.08logD-[4.26*0.16(mean*SE).As the next step, we included a real-time retinal blood vessel diameter measuring apparatus in the laser speckle velocimeter. The measurement of the vessel diameter and the of blood flow velocity could be performed at the same time. The reproducibility and accuracy of the apparatus was examined by measuring the width of the slits with 8 different widths on a chart paper, The reproducibility was 0.160*0.083%(Mean*SD) in coefficients of variance and the correlation coefficient between the measured values and the actual values was 0.999. The mean which was obtained by the method were within the range of 1.77*1.26%(Mean*>:) of the actual values. The blood flow diameters of 40 eyes of 20 normal volunteers were measured by this method and the microscopic method. Hence the reproducibility of the microscopy method was 7.2*5.4% (Mean*SD)in coefficients of variance, that of the image sensor method was 3.14*2.73%(Mean*SD). The correlation coefficient between those values were 0.835.