生物组织的光学特性参数与组织的各种生理、 生化以及病理过程密切相关。 光学特性参数的检测与三维重构可以在一定程度上了解组织的内部结构及特性。 基于频域近红外光谱法, 使用美国ISS公司的频域近红外光谱检测系统, 采用多光源多检测器技术, 将830 nm的激光经过调制后, 照射进放置了具有一定吸收系数和散射系数的异质体小球的牛奶中, 检测出射光的光强和相位, 然后应用光学扩散层析成像技术, 通过计算含有异质体小球的牛奶的光学参数, 重构出了牛奶中异质体的具体位置。 实验结果表明, 利用频域近红外光谱法得到的出射光的光强和相位信息, 能够较准确地计算出牛奶及异质体小球的吸收系数和散射系数等组织光学参数, 并可进一步定位出牛奶中异质体小球的位置。 因此, 可以考虑将该方法应用在分析及定位水果病变等农产品品质检测领域。

The optical parameters of biological tissue are closely related to tissue’s physiological, biochemical and pathological process. We could learn about the internal structure and characteristic of the biological tissue by determining and reconstructing the 3D image of optical scattering and absorption coefficients. Based on the frequency-domain near-infrared spectroscopy, the imagent system of ISS Corporation in USA and the technology of multi-source and multi-detector were used to complete the experiment. In the experiment, a tank was filled with milk and a little ball was put into the milk, we shined the modulated laser signal which wavelength was 830 nm into the milk and detected the intensity and phase of the emergent light. Then, optical diffusion tomography was used to reconstruct the location of little ball in the milk by calculating the optical scattering and absorption. Experiment results showed that we could calculate the optical scattering and absorption coefficients of the milk and the little ball accurately by using the frequency-domain near-infrared spectroscopy. And we could also locate the position of the little ball in the milk. Therefore, it was considered that the frequency-domain near-infrared spectroscopy could be applied in the field of agricultural product quality detection such as analysis the lesion location of the fruits and vegetables.