组织血流信息在临床诊断和治疗中具有重要的作用,无创血流检测是医患双方的期望。研究采用了近红外扩散相关光谱方法对生物组织血流进行无创检测,理论分析了散射光斑强度的变化和被测组织中血细胞运动状态的函数关系,建立了检测组织血流的理论模型及检测系统。该系统通过求解组织表面散射光斑电场强度的时间自相关函数来推断组织中血细胞的运动状态,进行组织血流的定量分析。采用健康人体前臂袖带加压实验模型对该系统进行了验证,实验结果验证了该系统进行组织无创血流检测的可行性,同时也表明该系统可以提供从浅层到深层的组织血流变化信息。
Blood flow plays an important role in clinical diagnosis and treatment, and noninvasive measurement of blood flow is the expectation of both doctors and patients. In the present work, the authors employed near-infrared diffuse correlation spectroscopy (DCS) method to measure blood flow noninvasively. The relationship between speckle intensity fluctuations of the scattering light and moving blood cells in tissue was theoretically analyzed. A theoretical model and blood flow measurement system were built. Blood flow was derived by calculating the electric field temporal autocorrelation function of speckle on tissue surface. Forearm blood flow was measured in healthy human subject during cuff inflation and deflation. Experimental results show that noninvasive blood flow measurement by this system is feasible. The results also suggest that this approach can provide blood flow information throughout the whole depth profile of the tissue.