A Novel Diffusion Irradiation Method to Monitor Thermal Effects on Deep Subcutaneous Vessels Using Laser Speckle Contrast Imaging

This study aims to investigate the effects of upper skin layers on laser light propagation and heat diffusion during laser surgery for vascular dermatosis. Using a rat dorsal window chamber model, deep-situated vessels are irradiated by a transcutaneous therapeutic laser, while blood flow changes are monitored using deep learning–enhanced laser speckle contrast imaging (LSCI) on the contralateral side. In vivo experiments on 20 Sprague Dawley rats were conducted to evaluate the thermal response of subcutaneous vessels at varying depths to long-pulsed 1064 nm Nd:YAG laser treatment under different parameters. Optimal laser settings are identified based on vessel morphology and blood flow velocity, ensuring effective thermal absorption for deeper vessels. By integrating LSCI with deep learning denoising techniques, this study presents a novel strategy for monitoring laser-induced effects on deep subcutaneous vessels, with potential applications in optimizing treatment strategies for vascular lesions.