Detection Of Blood Flow Velocity In Small Blood Vessels Based On Laser Speckle Imaging

Laser speckle imaging is a powerful method for imaging and characterizing blood flow in blood vessels.By performing statistical analysis on the speckle pattern of the laser speckle pattern on a rough surface or a medium containing a scattering substance,high-precision data on the rough surface image and the relative flow velocity distribution of the medium can be obtained.The application of laser speckle technology to the detection of small blood vessels in the human body has great academic value and clinical practical significance.This paper first derives the theory of laser speckle contrast algorithm in space and time domain,establishes a laser speckle image extraction program for small blood vessels,and builds a principle prototype of laser blood speckle technology for small blood flow detection.Later,wistar rats were used to carry out simulated blood flow identification and detection experiments.The temporal and spatial laser speckle contrast algorithms were mainly used to analyze the mesenteric blood vessels of white rats similar to human parathyroid blood supply vessels.The anesthetized mouse was fixed and the abdomen was cut open.The mesenteric blood vessels were exposed and irradiated with a 785 nm laser.The laser speckle image on the surface was captured with a complementary metal oxide semiconductor camera and transmitted to a computer.The mesenteric blood vessels were processed by the speckle contrast algorithm.Relative blood flow velocity distribution image,in order to identify the precise blood vessel contours of small mesenteric blood vessels,a method of performing secondary processing on the resulting image using image segmentation algorithms such as threshold segmentation and edge detection is proposed.The experimental results show that under certain experimental conditions,the outline and relative flow rate of mesenteric blood vessels can be better identified;the use of image segmentation algorithms can enhance the detection of small blood vessels;the effect of identifying dark mesenteric blood vessels is significantly better than light mesenteric blood vessels;blocked blood vessel areas can be accurately identified.The experimental device developed in this paper can help doctors to judge the condition of small blood vessels more accurately during surgery,and lay the foundation for the subsequent development of commercial medical devices.