以激光散斑衬比分析为基础的激光散斑成像技术, 是一种无需扫描的全场光学成像方法, 在监测生理及病理状态下组织血流动态变化中的应用日益广泛。在实际应用中, 像面散斑平均尺寸等多种因素影响散斑衬比值, 使得该技术在反映血流变化的准确性方面受到影响。采用一种成像散斑计算机模拟方法研究了像面散斑平均尺寸对成像散斑统计特性的影响, 分析了成像参数与像面散斑尺寸的定量关系, 并通过物理模型实验对模拟结果进行了验证。研究结果确认了合理的像面散斑平均尺寸计算公式, 证实了散斑衬比值随像面散斑平均尺寸增大而减小的现象, 并为确定合理的成像参数提供了依据。

Laser speckle imaging technique, based on laser speckle contrast analysis, is a full field optical imaging method which does not need scanning. It is getting increasing use in monitoring dynamic fluctuation of blood flow in tissues in physiological and pathological situations. In practice, various factors such as averaged image speckle size have impact on speckle contrast, making the accuracy of this technique affected in reflecting blood flow changes. This study investigates the impact of averaged image speckle size on statistical characteristics of image speckle pattern by simulating image speckle pattern. The quantitative relation between imaging parameters and averaged image speckle size is analyzed. The results are finally validated by phantom experiment. These results confirm the reasonable formula for calculating averaged image speckle size and the phenomenon that speckle contrast increases with increasing averaged image speckle size, providing a basis for determining reasonable imaging parameters.