牙本质各向异性光扩散属性

以牙本质为研究对象，提出一种各向异性生物组织光学散射特性的求解方法。从能量传输角度，引入扩散张量描述扩散方程，理论推导并结合各向同性立方体组织模型的光扩散规律，提出利用点光源入射规则切片产生的前向散射光能量分布的等高线椭圆长短轴之比来表示各向异性介质扩散张量的方法。实验测试了直径10 μm的点光源从两方向入射牙本质正方体切片前向散射光的能量分布图像，通过数据处理与分析，获得牙本质样本的扩散张量分量比值为DyyDzzDxx=7.491.31。最后，利用有限元数值方法求解正交各向异性扩散方程，获得前向散射光的能量分布，并与实验结果相对比，验证了结果的正确性。研究结果有助于加深对牙本质光学散射属性的了解，对基于光散射理论早期诊断龋病具有借鉴意义。

Abstract

Taking the dentine as the research object, a method to solve the light diffusion properties of anisotropic biological tissue is proposed. The diffusion tensor is introduced into the diffusion equation to describe the light propagation inside the tissue. Through theoretical derivation and considering light diffusion results of isotropic cubic tissue models, it is proposed that the ratio of diffusion tensor component can be expressed by ratio of long and short axes of forescattering contour ellipse incident by point light source. The experiment is performed to measure the forescattering light intensity distribution of dentine slice from two different directions incident by point light source of 10 μm diameter. The experiment result reveals that the ratio of diffusion tensor component of dentine is DyyDzz:Dxx=7.491.31. The orthogonal anisotropic diffusion equation is solved by finite element analysis method using ANSYS software by setting parameters as the obtained results. The simulated results are compared with the experimental data, and the correctness is confirmed. The study can deepen the understanding of scattering properties of dental dentine and gives the reference for the early detection of dental caries based on scattering effect.

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陈庆光, 徐英, 朱海华, 林斌, 陈晖. 牙本质各向异性光扩散属性[J]. 中国激光, 2013, 40(2): 0204001. Chen Qingguang, Xu Ying, Zhu Haihua, Lin Bin, Chen Hui. Anisotropic Light Diffusion Property of Dentin[J]. Chinese Journal of Lasers, 2013, 40(2): 0204001.

牙本质各向异性光扩散属性

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