National Cheng Kung University, Department of Mechanical Engineering, Tainan, Taiwan.
Kaohsiung Medical University, Center for Fundamental Science, Taiwan.
J Biomed Opt. 2017 Mar 1;22(3):35006. doi: 10.1117/1.JBO.22.3.035006.
The optical properties of biological tissues under stretching are investigated using a full-field ellipsometry technique based on a differential Mueller matrix formalism. Traditional photoelastic-based formalism for extracting the linear birefringence (LB) properties of stretched anisotropic optical samples ignores the effects of the other optical properties of the sample. By contrast, in the formalism proposed in this study, the LB, linear dichroism (LD), circular birefringence (CB), circular dichroism (CD), and depolarization (Dep) properties are fully decoupled. Simulations are performed to evaluate the performance of the two formalisms in extracting the LB properties of optically anisotropic samples with different degrees of Dep, CB, LD, and CD. The practical feasibility of the proposed all-parameter decoupled formalism is then demonstrated using chicken breast muscle tissue. In general, the results show that both formalisms provide a reliable LB measurement performance for healthy chicken breast tissue under stretching. However, while the LB-only formalism has good robustness toward scattering, its measurement performance is seriously degraded for samples with high CB. Thus, of the two formalisms, the proposed all-parameter decoupled formalism provides a more effective approach for examining the anisotropic properties of biological tissues under stretching.
采用基于差分 Mueller 矩阵公式的全场椭偏技术研究了拉伸状态下生物组织的光学特性。传统的基于光弹效应的提取各向异性光学样品线性双折射（LB）特性的公式忽略了样品其他光学特性的影响。相比之下，在本研究中提出的公式中，LB、线性二色性（LD）、圆双折射（CB）、圆二色性（CD）和去偏振（Dep）特性完全解耦。进行了模拟，以评估两种公式在提取具有不同 Dep、CB、LD 和 CD 程度的各向异性光学样品的 LB 特性方面的性能。然后，使用鸡胸肉组织验证了所提出的全参数解耦公式的实际可行性。总体而言，结果表明，两种公式在拉伸状态下对健康鸡胸肉组织的 LB 测量性能均可靠。然而，虽然仅 LB 公式对散射具有很好的稳健性，但对于具有高 CB 的样品，其测量性能会严重下降。因此，在这两种公式中，所提出的全参数解耦公式为检查拉伸状态下生物组织的各向异性特性提供了更有效的方法。
