Phantom of the Optics: Exploring Fluid Dynamics through Laser Speckle Contrast Imaging

Abstract

Laser Speckle Contrast Imaging (LSCI) is an evolving field in biomedical imaging, focusing on elucidating blood flow dynamics through analysis of speckle patterns generated by interactions with red blood cells (RBCs). This study explores how temporal and spatial contrast vary with flow speeds using LSCI. As established in previous LSCI research, spatial contrast is expected to decrease with increasing flow speeds, no such pattern has been generally established for its relation to temporal contrast. This study hypothesizes that temporal contrast will increase with flow speed, and that spatial contrast will align with what has been previously assumed in this field of study. A blood vessel phantom resembling blood flow in a human index finger was constructed, and basic LSCI components were employed alongside two lenses for imaging the phantom on to the camera. Results both deviated and aligned from expected patterns, with mean spatial contrast decreasing as flow rates increased from 3.0 - 7.0 mL/min, while maximum temporal contrast increased within this range. However, images at 2.0 mL/min exhibited significant deviation, indicating confounding factors. This study underscores the complexities of blood flow dynamics and the need for further investigation into their relationship with speckle contrast.