Reflected-Light Polarization Imaging to Quantify Tissue Microstructure and Damage

肌腱和韧带将力从肌肉传递到骨骼或骨骼之间。它们是由胶原蛋白制成的，对机械和化学损伤都很敏感。胶原蛋白损伤会改变肌腱或韧带的硬度和强度，导致疼痛和残疾。很难研究这种组织损伤，因为我们没有很好的实验室方法来观察它发生时的损伤。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。一种新型的摄像机可以看到肉眼看不见的光的特性，它将记录肌腱和韧带的线性结构是如何在导致损伤的载荷中断裂的。直观地跟踪在机械退化过程中胶原的降解将使测试防止损伤或治疗损伤的新方法成为可能。这项研究将培训研究生使用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电子书，以改进K-12学生的互动工作坊，并使社区更容易提供生物力学教材。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退化中的机械功能改变联系起来。该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。然后，这项技术将被用于跟踪疲劳负荷韧带的局部机械诱导损伤，并对肌腱随时间变化的生物诱导退化进行量化。RQPLI将克服以往方法的局限性，极大地促进偏振成像在肌肉骨骼力学中的应用。这项研究将检查以前无法评估的完整、大规模、全厚度组织，从而能够实时检测和量化加载过程中发生的特定区域、微观和结构变化。这一新的成像技术将增强组织微结构的光学测量，并推动偏振成像技术在肌肉骨骼生物力学中的应用。结果将为未来的项目奠定基础，这些项目将进一步推进多尺度力学和微观结构评估的研究，并加强对正常、受损、退化和愈合结缔组织的结构-功能关系的基本了解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.