基于散斑强度涨落调制效应的光学微血管造影成像技术的研究

The aim of this project is, based on the intensity fluctuation of laser speckle, to develop a high spatial-resolution optical micro-angiography available for the retina or small animal models, and realize the oxyhemoglobin saturation distribution image and accurate speed measurement of a red cell in micro-vessel. Its main contents includes: by using a pulse laser triggered at the same time same as the camera,it can greatly reduce the average illuminating power in order to meet the safe standard of biomedical tissue; by letting the camera work in the short-exposure and long-sampling mode, it can record and separat the signals of dynamic and static laser speckles in the frequency domain; by taking modulation depth as the image parameter, it can reconstruct the two-dimension optical micro- angiography; by combining with the optical projection tomography, to obtain three-dimension optical micro-angiography; by using two-wavelength laser source, it can realize the oxyhemoglobin saturation image; by appplying the temporal or spatial autocorrelation method, it can accurately measure the speed of the red cell. The technique developed in our project is very importance and potential for the ophthalmologic diagnostics and the microangiopathy research.

本项目旨在发展一种能够应用到眼底视网膜和小动物模型二维 、三维光学微血管造影成像技术，并能够实现微血管内血氧饱和度的功能成像和红细胞移动速率的准确测量。主要内容包括：通过采用脉冲激光器和相机曝光同步触发的方法，有效降低激光照射的平均功率，使之达到生物组织（尤其是眼底视网膜组织）的安全阈值；采用短曝光-长采样的相机工作模式记录散斑图像，通过选择合适的滤波频率，将动态散斑信号和静态散斑、背景噪声信号在频域分离；采用调制深度为成像参量，实现二维的光学微血管造影成像；通过与光学投影层析成像结合，实现三维光学血管层析成像；采用双波长激光照明方式，实现微血管的血氧饱和度成像；在重建出微血管图像的基础上，采用时间或者空间相关的方法，精确测量红细胞的移动速率。项目拟发展的技术对临床眼科检测、诊断和微血管病变的机理研究有重要的价值，具有很好的应用前景。

本项目旨在发展一种能够应用到眼底视网膜和小动物模型二维 、三维光学微血管造影成像技术，并能够实现微血管内血氧饱和度的功能成像和红细胞移动速率的准确测量。主要内容包括：通过采用脉冲激光器和相机曝光同步触发的方法，有效降低激光照射的平均功率，使之达到生物组织（尤其是眼底视网膜组织）的安全阈值；采用短曝光-长采样的相机工作模式记录散斑图像，通过选择合适的滤波频率，将动态散斑信号和静态散斑、背景噪声信号在频域分离；采用调制深度为成像参量，实现二维的光学微血管造影成像；通过与光学投影层析成像结合，实现三维光学血管层析成像；采用双波长激光照明方式，实现微血管的血氧饱和度成像；在重建出微血管图像的基础上，采用时间或者空间相关的方法，精确测量红细胞的移动速率。项目拟发展的技术对临床眼科检测、诊断和微血管病变的机理研究有重要的价值，具有很好的应用前景。