Reflected-Light Polarization Imaging to Quantify Tissue Microstructure and Damage

肌腱和韧带将力量从肌肉传递到骨骼或骨骼之间。它们是由易受机械和化学损伤的胶原蛋白制成的。胶原蛋白损伤会改变肌腱或韧带的硬度和强度，从而导致疼痛和残疾。研究这种类型的组织损伤是很困难的，因为我们没有很好的实验室方法来观察损伤的发生。这项研究将使用一种新的成像技术，可以看到机械加载过程中组织的变化。一种新型摄像机可以看到人眼看不见的光的特性，它将记录下肌腱和韧带的线性结构是如何被载荷破坏的。视觉跟踪胶原蛋白在机械变性过程中的降解，将有可能测试新的方法来防止损伤或治疗损伤。这项研究将训练研究生掌握先进的生物力学方法。该项目包括编写一本关于韧带和肌腱功能的多媒体iBook，以改善K-12学生的互动研讨会，并使其更容易向社区提供生物力学教育材料。本研究的目的是利用偏振成像来推进结缔组织的微观结构分析，并将软组织的动态组织与损伤和变性中改变的机械功能联系起来。本项目将利用组织模拟实验系统和计算模拟建立一种新的反射光定量偏振光成像（rQPLI）技术。该技术随后将用于追踪疲劳韧带的局部机械损伤，并量化随时间变化的生物诱导肌腱变性。rQPLI将克服以往方法的局限性，极大地推进极化成像在肌肉骨骼力学中的应用。这项研究将检查完整的、大规模的、全层的组织，这在以前是不可能评估的，能够实时检测和定量加载过程中发生的区域特异性、微观结构变化。这种新型成像技术将增强组织微观结构的光学测量，并推动极化成像技术在肌肉骨骼生物力学中的应用。研究结果将为未来的项目奠定基础，进一步推进多尺度力学和微观结构评估的研究，并增强对正常、损伤、退化和愈合结缔组织结构-功能关系的基本理解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Tendons and ligaments transfer forces from muscle to bone or between bones. They are made of collagen that is susceptible to both mechanical and chemical damage. Collagen damage can change the stiffness and strength of tendons or ligaments to cause pain and disability. It is difficult to study this type of tissue injury because we don't have good laboratory methods to see the damage as it occurs. This research will use a new imaging technique that can see tissue changes during mechanical loading. A novel video camera that sees properties of light that are invisible to the human eye will record how the linear structures of the tendons and ligaments are broken by loading that causes damage. Visually following the degradation of the collagen during the process of mechanical degeneration will make it possible to test new methods to prevent damage or to treat the injuries. The research will train graduate students in advanced biomechanics methods. The project includes writing a multimedia iBook on ligament and tendon function to improve interactive workshops for K-12 students and to make it easier to give biomechanics educational materials to the community.The objective of this research is to use polarization imaging to advance the microstructural analysis of connective tissues and link the dynamic organization of soft tissues to altered mechanical function in damage and degeneration. This project will establish a novel reflected-light quantitative polarization light imaging (rQPLI) technique using a tissue analog experimental system and computational simulations. This technique will then be used to track local, mechanically-induced damage in fatigue-loaded ligament and to quantify time-dependent biologically-induced degeneration in tendon. rQPLI will overcome limitations of previous approaches and greatly advance polarization imaging for use in musculoskeletal mechanics. This study will examine intact, large-scale, full-thickness tissues that were impossible to evaluate previously, enabling detection and quantification of region-specific, microscopic, structural changes that occur during loading in real-time. This novel imaging technique will enhance optical measurement of tissue microstructure and advance polarization imaging techniques for applications in musculoskeletal biomechanics. Results will lay the foundation for future projects that further advance study of multiscale mechanics and microstructural evaluation, and enhance fundamental understanding of structure-function relationships in normal, damaged, degenerate, and healing connective tissues.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.