Laparoscopic multi-exposure speckle imaging for quantitative flow measurement

Multiple studies have demonstrated that laser speckle contrast imaging (LSCI) can be a valuable blood flow monitoring technique during laparoscopic operations. However, the quantitative accuracy of traditional single-exposure LSCI is limited. In this paper, an extension to LSCI called multi-exposure speckle imaging (MESI) can overcome this limitation and is evaluated in a commercially available laparoscopic setting. Our laparoscopic MESI system records multiple exposure times spanning 3 ms–20 ms. We demonstrate that the laparoscopic MESI estimates provide the sensitivity for sampling the flow magnitude in a phantom with different channel sizes. Conservation of flow analysis on the rabbit vascular branch is also used to validate the accuracy of flow estimates from MESI. Our results demonstrate that laparoscopic MESI can be performed with the ability of quantitative blood flow measurements and shows the potential to be clinically useful for monitoring blood flow.