Poroelastic Wave Propagation in Anisotropic Bone

该奖项的研究目标是检查骨小梁微结构变化与测量的多孔弹性超声波特性之间的因果关系。通过流体饱和的多孔介质（例如骨小梁）传播的超声波的能量产生两种不同的多孔弹性波，其以取决于骨的固体和流体成分的性质的速度和衰减行进。 根据该奖项进行的研究将使用分析，数值和实验方法来确定孔隙微结构，材料特性和波频率变化对这两种波的速度和衰减的影响。拟议的参数研究将在3D打印多孔介质模型中的实验和有限差分时域数值模拟中研究波的传播特性。将使用各向异性多孔弹性理论方法来区分固体和流体成分对3D打印模型和人类小梁骨中测量的超声波信号的贡献。本研究的长期目标是将用于评估骨质疏松症的技术从目前标准的电离和昂贵的DEXA设备转变为更低成本的非电离超声系统，该系统可以访问微结构以及材料特性。如果成功，这种基于结构的方法将揭示超声波在多孔介质中传播的主要微结构决定因素，并将改善骨丢失和骨质疏松期间骨小梁变化的非侵入性表征。该奖项的教育部分侧重于为纽约城市学院代表性不足的本科生开发骨生物力学和生物医学成像的多学科课程，增加课程模块的数量，包括数值建模，研究设计和成像动手实验室经验。该计划将为本科生提供密切指导的研究机会，以吸引他们参加STEM研究生课程。

The research objective of this award is to examine the cause-effect relationship between changes in trabecular bone microarchitecture and measured poroelastic ultrasound wave properties. The energy of an ultrasound wave propagating through a fluid-saturated porous medium such as trabecular bone creates two distinct poroelastic waves which travel with velocities and attenuations that depend on the properties of solid and fluid constituents of bone. Studies conducted under this award will use analytical, numerical and experimental approaches to determine the effect of changes in pore microarchitecture, material properties and wave frequency on the velocity and attenuation of these two waves. The proposed parametric study will investigate wave propagation properties in both experimental and finite-difference time-domain numerical simulations in 3D printed porous medium models. An anisotropic poroelastic theoretical approach will be used to distinguish the contribution of solid and fluid constituents on measured ultrasound wave signals in both 3D printed models and human trabecular bones. The long-term objective of this research is to change the technology used for the assessment of osteoporosis from the current standard of ionizing and expensive DEXA devices to lower cost, non-ionizing ultrasound systems that access microarchitecture as well as material properties.If successful, this architectural-based approach will reveal the main microarchitectural determinants of ultrasound wave propagation in porous media, and will improve the non-invasive characterization of changes in trabecular bone during bone loss and osteoporosis. The educational component of this award focuses on developing a multidisciplinary program on bone biomechanics and biomedical imaging for undergraduate students from underrepresented groups at the City College of New York, increasing the number of course modules with numerical modeling, research design and imaging hands-on laboratory experience. The program will provide closely mentored research opportunities for undergraduate students to attract them to follow graduate studies in STEM.