Noninvasive Measurement Of Strain And Mechanical Properties In Tendons/Ligaments

肌腱/韧带应变和机械性能的无创测量

• 批准号: 7659261
• 负责人: RAY VANDERBY
• 金额: $ 18.17万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-15 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7659261
• 关键词: Accounting; Acoustics; Algorithms; American Cancer Society; Animal Model; Animals; Area; Arteries; Behavior; Benign; Biomechanics; Clinical; Cost Savings; Data; Defect; Degenerative polyarthritis; Development; Diagnosis; Diagnostic; Diagnostic Neoplasm Staging; Diagnostic Procedure; Disabled Persons; Failure; Family suidae; Flexor; Healed; Histocompatibility Testing; Image; In Situ; In Vitro; Investigation; Joint Laxity; Knee; Knowledge; Ligaments; Limb structure; Magnetic Resonance Imaging; Maintenance; Malignant - descriptor; Malignant neoplasm of prostate; Mammary Neoplasms; Maps; Marfan Syndrome; Measurement; Measures; Mechanics; Medical; Medicare; Methods; Modeling; Mus; Musculoskeletal; National Institute of Arthritis and Musculoskeletal and Skin Diseases; Operative Surgical Procedures; Orthopedics; Pathologic; Population; Property; Public Health; Publishing; Rattus; Recovery; Rehabilitation therapy; Research Personnel; Resolution; Rupture; Shoulder; Signal Transduction; Simulate; Skin; Specimen; Sprain; Stress; Stretching; Surgeon; System; Techniques; Technology; Tendinitis; Tendon structure; Testing; Time; Tissues; Tumor stage; Ultrasonic wave; Ultrasonography; Visit; Woman; achilles tendon; base; clinically relevant; cost; efficacy testing; handicapping condition; healing; improved; in vivo; innovation; interest; ligament injury; malignant breast neoplasm; mathematical theory; men; musculoskeletal imaging; novel diagnostics; programs; public health relevance; soft tissue; theories; tool; tumor

DESCRIPTION (provided by applicant): We propose a new paradigm for ultrasound wave analysis in order to non-invasively compute mechanical properties (nonlinear stiffness) and functional strains in ligaments and tendons. Mechanical properties can diagnose damage or a pathologic state (i.e. tendonitis or tendinosis) and it can quantify the extent of healing. Tissue strains indicate functional loadings for rehabilitation and recovery. If successful, our method will significantly improve upon existing methods and find numerous applications that benefit public health. And, it will provide an improved tool for scientific inquiry in many musculoskeletal studies of relevance to NIAMS. This study applies acoustoelasticity (AE) to biomedical ultrasound imaging for the first time. AE is a mathematical theory that rigorously describes ultrasonic wave propagation in deformed elastic materials, interrelating reflected waves to mechanical properties and strain. After a tissue such as tendon or ligament is stretched (i.e. functionally loaded), AE models wave propagation in a deformed medium more accurately than existing methods. Currently, other ultrasound-based methods use "wave theory", which does not account for deformation-dependent changes in wave velocity and amplitude. Preliminary studies clearly show that "wave theory" analysis can cause significant errors when ultrasound is used to compute tissue properties. AE analysis has the potential to: 1) avoid these errors, 2) include tissue non-linearities, 3) acquire all requisite data with one functional loading, and 4) compute strain and mechanical properties in virtually real time. This technique does not require additional force measurements or time-consuming numerical modeling to extract properties. To our knowledge, no existing method can evaluate both applied strain and nonlinear tissue properties simultaneously in virtually real time. This study will test the efficacy of an AE-based technique termed "Acoustoelastic Strain Gauge" (ASG) on animal tendons (tendons in rat and pig limbs after sacrifice). Tendons will be analyzed in situ, that is, through skin and superficial tissues while being stretched with a mechanical test system. In this study ASG will be applied to porcine flexor tendons (intact and with induced subfailure damage to simulate various levels of 2nd degree sprains). ASG will be applied to rat Achilles tendons (intact and after surgical rupture and various periods of healing). In both animal models, applied strain and strain-dependent tissue properties of the in situ stretched tendons will be evaluated. Strain from ASG will be correlated with strain from a mechanical test system to demonstrate accuracy and repeatability of the ASG technique. This study will determine the ability and sensitivity of ASG to quantify the level of sub-failure damage (as determined by a reduction in ultimate force). Finally, this study will determine the ability of ASG to predict strength recovery during healing. PUBLIC HEALTH RELEVANCE: We propose a new and different method of ultrasound wave analysis to non-invasively measure mechanical properties and functional strains in soft tissues. If successful, this new diagnostic tool be a significant improvement over existing methods and will find numerous applications that benefit public health. Consider, for example, functional strain measurement. In the U.S. more than 12 million people visited orthopedic surgeons in 2003 because of either knee or shoulder problems. Knee ligament injuries are common, and almost all shoulder problems are related to stretched or ruptured tissues with altered functional loads. Consider, for example, mechanical property identification. The American Cancer Society estimated in 2005 that approximately 211,240 women were diagnosed with invasive breast cancer in the U.S. and 232,090 men were diagnosed with prostate cancer. Clearly, non-invasive tissue strain to measure functional loads and non-invasive mechanical properties to distinguish and identify tissue types would be valuable. Our method has the potential to improve upon existing methods in these areas. A recent study in a Medicare population projected that musculoskeletal imaging costs in 2020 will be $3.6 billion, of which $2 billion will be for MRI. Investigators estimated 45% of the MRI diagnoses could have been made with ultrasound, and if appropriately substituted, could result in cost savings of nearly $7 billion over the next 14 years. Innovative developments in ultrasound technology may create value added features resulting in increased interest and significant.

描述（由申请人提供）：我们提出了一种用于超声波分析的新范例，以非侵入性地计算韧带和肌腱中的机械特性（非线性刚度）和功能应变。机械性能可以诊断损伤或病理状态（即肌腱炎或肌腱病），并且可以量化愈合程度。组织应变表明康复和恢复的功能负荷。如果成功，我们的方法将大大改善现有的方法，并找到许多有益于公共卫生的应用。而且，它将为许多与NIAMS相关的肌肉骨骼研究提供一个改进的科学探究工具。 本研究首次将声弹性应用于生物医学超声成像。AE是一种数学理论，它严格描述了超声波在变形弹性材料中的传播，将反射波与机械性能和应变联系起来。在诸如肌腱或韧带的组织被拉伸（即功能性加载）之后，AE比现有方法更准确地对变形介质中的波传播进行建模。目前，其他基于超声的方法使用“波动理论”，其不考虑波速和振幅的变形相关变化。初步研究清楚地表明，当超声用于计算组织特性时，“波动理论”分析可能会导致重大错误。AE分析有可能：1）避免这些错误，2）包括组织非线性，3）用一个功能载荷获得所有必要的数据，以及4）几乎真实的时间计算应变和机械性能。该技术不需要额外的力测量或耗时的数值建模来提取属性。据我们所知，没有现有的方法可以同时在几乎真实的时间内评估所施加的应变和非线性组织特性。本研究将测试基于AE的称为“声弹性应变计”（ASG）的技术对动物肌腱（处死后大鼠和猪肢体的肌腱）的有效性。肌腱将进行原位分析，即通过皮肤和浅表组织，同时使用力学测试系统进行拉伸。在本研究中，ASG将应用于猪屈肌腱（完整且具有诱导的亚失效损伤，以模拟各种水平的2度扭伤）。ASG将应用于大鼠跟腱（完整和手术破裂后以及不同愈合期）。在两种动物模型中，将评价原位拉伸肌腱的施加应变和应变依赖性组织特性。将ASG产生的应变与机械测试系统产生的应变相关联，以证明ASG技术的准确性和可重复性。本研究将确定ASG量化子失效损伤水平的能力和灵敏度（由极限力的降低确定）。最后，本研究将确定ASG预测愈合期间力量恢复的能力。 公共卫生关系：我们提出了一种新的和不同的超声波分析方法，以非侵入性地测量软组织的机械性能和功能应变。如果成功，这种新的诊断工具将是对现有方法的重大改进，并将发现许多有益于公共卫生的应用。例如，考虑功能应变测量。在美国，2003年有超过1200万人因为膝盖或肩膀问题而去看整形外科医生。膝关节韧带损伤很常见，几乎所有的肩部问题都与功能负荷改变导致的组织拉伸或断裂有关。例如，考虑机械性能识别。美国癌症协会在2005年估计，美国约有211，240名女性被诊断患有浸润性乳腺癌，232，090名男性被诊断患有前列腺癌。显然，测量功能载荷的非侵入性组织应变和区分和识别组织类型的非侵入性机械特性将是有价值的。我们的方法有可能改善这些领域的现有方法。最近一项针对医疗保险人群的研究预测，到2020年，肌肉骨骼成像费用将达到36亿美元，其中20亿美元将用于MRI。研究人员估计，45%的MRI诊断可以通过超声进行，如果适当替代，可以在未来14年内节省近70亿美元的成本。超声技术的创新发展可以创造增值功能，从而增加兴趣和意义。