Time varied illumination laser speckle contrast imaging

Laser speckle contrast imaging is a technique to determine blood flow rate with a limitation of low dynamic range. In this Letter, we introduce a varied illumination speckle contrast imaging method. It utilizes varying illumination during exposure to customize the correlation time (flow rate) to speckle contrast relation. The method can cover an order of magnitude larger range flow rate in a single exposure compared to constant illumination methods. The proposed method enables high dynamic range flow rate imaging, which is advantageous in studying larger vessels and small arteries. We demonstrate the theory by simulations and ex vivo and in vivo measurements. (C) 2021 Optical Society of America

Automated summary

The varied illumination speckle contrast imaging method introduced in this Letter allows for a larger range of flow rate coverage in a single exposure compared to constant illumination methods. This enables high dynamic range flow rate imaging, advantageous for studying larger vessels and small arteries. The method was demonstrated through simulations and measurements in ex vivo and in vivo settings.