Use of speckle patterns in optical coherence tomography images for characterization of microfluidic circuits and microcirculation in tissue

Abstract

The Optical Coherence Tomography provides an image with spatial resolution of order of a few microns. This image provides information on depth structures present in scattering samples. An important feature of these images is the speckle pattern present in it resulting from light interference processes, which mostly is either neglected or subtracted from original images with goal of improving its contrast. The research project proposed here in is intended to use the speckle information present in the OCT images to determine the flow speed of fluids in microchannels by applying and adapting already known techniques for speckle analysis (e.g, laser speckle imaging). The main differential feature of this proposal is to construct images of scattering materials containing microchannel or capillary channels, and use the speckle variance as the main parameter for analysis, allowing in the same image morphological and functional information with depth spatial resolution, to determine the flow of liquids in capillary immersed in scattering media or in transparent media with scattering liquids flows..This research project aims, besides characterizing dimensionally microfluidic circuits, study and adapt the algorithms of speckle variance to determine velocities in microfluidic flows and to determine the variation of capillaries blood flow in inflammatory mice tissue. (AU)