基于光子在生物组织中的辐射传输理论以及Feng模型, 应用频域近红外光谱法研究生物组织中异质体位置的变化, 对出射光的光强和相位变化的影响及规律。 设计了一仿真实验, 用牛奶代替强散射性质的生物组织, 并在牛奶中放置一个高度可控的具有一定吸收系数和散射系数的小球。 移动小球在牛奶中的高度, 检测出射光的交流幅度AC、 直流光强DC和相位延迟Phase的值, 绘制小球位于不同深度时AC, DC和Phase的曲线, 并探讨其变化规律。 结果表明, 随着小球在牛奶中深度的变化, 光强AC, DC和相位Phase呈现一定的相关性; 随着光源和检测器之间距离的增加, 检测到的光强和相位曲线的波谷点均向右偏移; 当小球偏离光源和检测器越远, 对检测到的光强和相位的影响越小。 验证了光子在生物组织中的传输规律, 为用频域近红外光谱法进行组织光学参数的检测及组织中异质体位置的定位奠定了基础。

Based on the theory of photon radiative transfer in biological tissue and Feng model, we applied frequency-domain near-infrared spectroscopy to study the position changes of the little ball in the biological tissue how to influence the intensity and phase of emergent light, and learn if there are regularities of the intensity and phase changing. A simulation experiment was designed using the milk as biological tissue and a little ball as the tissue lesions. The ball was fixed to a thin rod and allowed to be moved up and down in the milk. At every step of the little ball, data of AC, DC and Phase were collected and stored in files that were then converted to waveform in Matlab. According to the results of the experiment, the variation trend of the AC and DC plot were displayed same, and the phase plot does indeed display the biphasic behavior. The valleys of the AC, DC and Phase plots were all offset to the right with the increasing of distance between light sources and detectors. And the greater degree of ball deviating from the light sources and detectors, the smaller effects that the ball acted on intensity and phase detected. With the discussion of the results, we could finally delve into the heart of this set of experiments, which was to show that the photons transmission was confirmed concerning the theory of radiative transfer. This research also established foundation to detect the tissue parameters and locate the position of tissue lesions by frequency-domain near-infrared spectroscopy.