高灰度级高分辨率激光散斑血流实时成像研究

Real-Time Laser Speckle Imaging of Blood Flow with High Gray Level and High Resolution

激光散斑对比成像是一种大测量范围、实时、高分辨率的光学成像方法.现有研究表明,低灰度级(8位)低分辨率(752像素×480像素)照相机可以有效监测血液等散射介质流动,但散粒噪声大、有效成像区域小等缺点难以通过软件弥补,严重影响成像质量.使用高灰度级(16位)高分辨率(2 048像素×2 048像素)照相机监测血液流动会减慢单帧成像速度,并行计算能使图像处理时间减少1/3.研究借助动物血液流动实验,以成像速度与成像质量为评价标准,对比分析高灰度级高分辨率空间激光散斑对比成像与空间近似激光散斑对比成像(sLSCIa)、时间激光散斑对比成像(tLSCI)的结果.结果表明,高灰度级高分辨率空间激光散斑对比成像并行计算兼顾成像质量与成像速度,可以达到临床实时监测血液流动要求.

Laser speckle contrast imaging(LSCI)is a large measurement ranging,real-time,high spatial resolution optical imaging method.Exisiting reserches show that the low gray level(8-bit)and low resolution(752×480 pixels)camera can effectively monitor the flow of scattering media such as blood,but the defects such as large noise of scattered particles and small effective imaging area are difficult to be compensated by software,which seriously affects the imaging quality.Monitoring blood flow with a camera with a high gray level(16-bit)and a high resolution(2048×2048 pixels)will slow down the imaging speed of a single frame,and parallel computing can reduce the image processing time by 1/3.With the aid of an animal blood flow experiment,the results of high-gray-level and high-resolution spatial laser speckle contrast imaging(sLSCI),spatial approximate laser speckle contrast imaging(sLSCIa),and temporal laser speckle contrast imaging(tLSCI)were compared and analyzed using imaging speed and imaging quality as evaluation criteria.The parallel computation of high-gray-level and high-resolution sLSCI takes into consideration both imaging quality and imaging speed,which can meet the requirements of clinical real-time monitoring of blood flow.