Confocal laser speckle time-autocorrelation imaging with adaptive orientation spatial windows

Conventional laser speckle contrast imaging (LSCI) suffers from static scattering and limited quantitative accuracy. To overcome these issues, we previously developed confocal laser speckle contrast imaging (CLSCI) and confocal laser speckle autocorrelation imaging (CLSAI), which enhanced spatial and temporal resolution, respectively. However, CLSAI remains sensitive to noise and computational inefficiency. In this work, we propose an adaptive orientation spatial window method for confocal laser speckle time-autocorrelation imaging. By selecting the optimal orientation with maximal spatial variance for each pixel, this method effectively suppresses noise, improves autocorrelation fitting accuracy, and reduces computational load, enabling real-time microcirculation monitoring. Experimental validation in in vivo zebrafish blood flow imaging demonstrates significant noise reduction and precise capture of cardiac-cycle-dependent blood flow velocity fluctuations. The proposed approach achieves high spatial resolution and real-time performance, offering a robust foundation for future clinical microvascular blood flow assessment.