Miao Peng, Chao Zhen, Zhang Yiguang, Li Nan, Thakor Nitish V
Opt Lett. 2014 Jul 1;39(13):3907-10. doi: 10.1364/OL.39.003907.
Dynamic laser speckles contain motion information of scattering particles which can be estimated by laser speckle contrast analysis (LASCA). In this work, an entropy-based method was proposed to provide a more robust estimation of motion speed. An in vitro flow simulation experiment confirmed a simple linear relation between entropy, exposure time, and speed. A multimodality optical imaging setup is developed to validate the advantages of the entropy method based on laser speckle imaging, green light imaging, and fluorescence imaging. The entropy method overcomes traditional LASCA with less noisy interference, and extracts more visible and detailed vasculatures in vivo. Furthermore, the entropy method provides a more accurate estimation and a stable pattern of blood flow activations in the rat's somatosensory area under multitrial hand paw stimulations.
动态激光散斑包含散射粒子的运动信息，可通过激光散斑对比度分析（LASCA）进行估计。在这项工作中，提出了一种基于熵的方法来更稳健地估计运动速度。体外流动模拟实验证实了熵、曝光时间和速度之间存在简单的线性关系。开发了一种多模态光学成像装置，以验证基于激光散斑成像、绿光成像和荧光成像的熵方法的优势。熵方法克服了传统LASCA存在的噪声干扰较小的问题，在体内提取出更清晰、更详细的血管系统。此外，熵方法在多次手部刺激下，能更准确地估计大鼠体感区的血流激活情况，并提供更稳定的血流激活模式。
