Collaborative Research: Mechanical Characterization of Bio-Interfaces by Shear Wave Scattering

人体组织的正常机械特性通常不同于癌性肿瘤的机械特性。 该研究项目的一个目标是创建一种新的方法来测量活体患者体内组织的机械特性。 一种称为“磁共振（MR）弹性成像”的测量机械性能的现有方法是有吸引力的，因为它不使用破坏性辐射。 然而，它现在还不够准确地测量肿瘤和正常组织之间的界面特性。 需要克服的问题之一是，MR弹性成像在组织均匀时是准确的，但在正常组织和肿瘤之间的界面处是不准确的。 这种界面的不准确性使得更难看到小肿瘤，而这些小肿瘤正是那些需要被发现以进行早期治疗的肿瘤。 该研究项目将通过实验确定图像在界面处退化的原因，然后创建改善图像的理论。 新方法将使用从患者收集的真实的数据进行测试，以确定它是否不仅改善了实验系统的成像，而且改善了患者的成像。 该研究将支持NSF促进科学进步的使命，并通过推动医疗技术的进步，为促进国民健康的目标做出贡献。该项目将为K12，本科生和研究生的多元化群体提供推广，培训和指导机会。研究小组还将与国家和国际媒体合作，向公众传播研究结果。该项目将提供一种新的方法，用于将生物界面的机械强度和顺应性与非侵入性波散射数据相关联，从而为此类界面的物理化学性质的诊断提供安全手段。特别是，波传播的粘性摩擦界面将被建模，并将开发一个基于波散射的表征方法，以确定界面的机械性能。此外，先进的激光振动测量技术（多点激光振动测量）将被用来测量剪切波散射跨越软合成界面。这些测量值将作为表征方法的验证数据集。最后，将使用MR弹性成像测量来测试该方法的有效性。这最后一步将揭示目前在实践中的局限性，并为下一代基于MR的诊断提供指导方针。该奖项反映了NSF的法定使命，并已被认为值得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的支持。

The normal mechanical properties of the tissues of the human body are often different from those of cancerous tumors. A goal of this research project is to create a new approach to measuring the mechanical properties of body tissues in living patients. An existing method to measure mechanical properties called "magnetic resonance (MR) elastography" is attractive because it does not use damaging radiation. However, it is not now sufficiently accurate to measure the interface properties between tumors and normal tissue. One of the problems to overcome is that MR elastography is accurate when tissue is uniform, but it is inaccurate at the interface between normal tissue and tumor. This interface inaccuracy makes it more difficult to see small tumors, exactly those that need to be detected for early treatment. This research project will determine experimentally why the image is degraded at an interface, and then create a theory to improve the images. The new method will be tested using real data collected from patients to determine if it improves imaging not only for the experimental system, but also for the patients. The research will support NSF's mission of promoting progress of science and contribute to the goal of advancing national health by enabling advances in medical technologies. This project will provide outreach, training and mentoring opportunities as well for a diverse group of K12, undergraduate and graduate research students. The research team will also collaborate with the national and international media to disseminate the findings to the public. This project will provide a novel methodology for relating mechanical strength and compliance of bio-interfaces to noninvasive wave scattering data, and thus provide safe means for diagnostics of physicochemical nature of such interfaces. In particular, wave-propagation across cohesive-frictional interfaces will be modeled, and a wave-scattering-based characterization methodology will be developed to identify the mechanical properties of the interfaces. Moreover, an advanced laser vibrometry technique (multipoint laser vibrometry) will be utilized to measure shear wave scattering across soft synthetic interfaces. Those measurements will serve as validation datasets for the characterization methodology. Lastly, the efficacy of the methodology will be tested with MR Elastography measurements. This final step will reveal the current limitations in practice, and provide guidelines for the next-generation of MR-based diagnostics.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.