MECHANICAL ORGINS OF SHOCK INDUCED BIOEFFECTS IN SHOCK WAVE LITHOTRIPSY

冲击波碎石术中冲击引起的生物效应的机械根源

• 批准号: 3733209
• 负责人: BRADFORD STURTEVANT
• 金额: --
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3733209
• 关键词: biophysics; iatrogenic disease; kidney function; lithotripsy; mechanical pressure; mechanical stress; miniature swine; phantom model; tissue /cell culture; ultrasound biological effect

The proposed research will provide the foundation for interpretating modes of renal injury induced by SWL in terms of the mechanical stress generated by shock waves focusing in tissue. The stress waves are directly to the strength and geometry of the shock waves, and, therefore, to the operation of lithotriptors. Thus, understanding the linkage between mechanical effects of shock waves and medical injury will permit new treatment guidelines to be formulated. The specific aim of this project are: 1. Measure the properties of mechanical stresses induced in mini-swine and cell-culture models in experiments at Indiana University (IU), and correlate with observations of renal injury. This phase of the study will test the hypothesis that a) measurable or calculable properties of the mechanical stress fields imposed by focusing shock waves can be correlated with observations of shock-wave-induced injury in SWL. 2. Determine if stress induced by shock interaction with tissues leads to differential motions, such as shear and tearing, which cause mechanical failure of biological structural elements. This work, is designed to test the hypothesis that b) interactions of SWL shock waves with acoustic inhomogeneities in tissues cause stresses and differential motions which lead to mechanical failure of biological structural elements. The mechanical stresses induced in the kidney of mini-swine during lithotripsy will be measured using newly tested methodology employing implantable thin-film pressure transducers. The transducers will measure the stresses imposed directly on the kidney and modifications to the stress waves as they propagate through the body. The stresses applied to living cells by SWL shock waves will also be measured using transducers installed directly into plastic vials containing cell cultures. Incorporating pressure transducers in both in vivo and in vitro tests makes it possible for the first time to tailor the conditions of the in vitro study to replicate the mechanical state experienced in the in vivo environment. Approximate theories of shock wave propagation will be used to develop numerical models of shock focusing in tissue. An important element of medical physics, previously not considered, concerns the mechanisms by which shock waves cause failure in weak structural elements, such as membranes and thin-walled liquid-filled vessels. An exploratory study of the mechanisms of shock-induced failure in simple mechanical models of biological structures will be undertaken using appropriate transparent materials and high-speed photographic flow- visualization techniques. Data from the mini-pig, cell-culture, and shock-failure experiments, taken both individually and as a whole, will be used in an iterative process to improve the design and interpretation of each type of experiment.

本文的研究将为解释模式提供基础 在产生的机械应力方面， 通过冲击波在组织中聚焦 应力波直接到达 冲击波的强度和几何形状，因此， 碎石机 因此，理解机械和机械之间的联系 冲击波和医疗损伤的影响将允许新的治疗方法 制定指导方针。 该项目的具体目标是： 1. 测量在小型猪中引起的机械应力的特性， 印第安纳州大学（IU）实验中的细胞培养模型，以及 与肾损伤的观察结果相关。 本阶段研究将 测试假设，a）可测量或可计算的属性， 由聚焦冲击波施加的机械应力场可以被关联 观察冲击波引起的SWL损伤。 2. 确定冲击与组织相互作用引起的应力是否导致 差动运动，如剪切和撕裂，造成机械 生物结构要素的失效。 这项工作，旨在测试 假设B）SWL冲击波与声波的相互作用 组织中的不均匀性引起应力和差动运动， 导致生物结构元件机械故障。 小型猪肾脏组织中的机械应力 碎石术将使用新测试的方法进行测量， 可植入薄膜压力传感器。 传感器将测量 直接施加在肾脏上的应力和对应力的修改 波在身体中传播的时候。 生活中的压力 还将使用安装的传感器测量SWL冲击波对细胞的影响 直接放入装有细胞培养物的塑料瓶中。 结合 压力传感器在体内和体外测试中的应用使得 首次定制体外研究的条件， 复制在体内环境中经历的机械状态。 冲击波传播的近似理论将被用来发展 组织中冲击聚焦的数值模型。 医学物理学的一个重要元素，以前没有考虑过， 关于冲击波引起弱断裂的机制， 结构元件，如薄膜和薄壁充液 船舶. 冲击破坏机理的探讨 在生物结构的简单力学模型中， 使用适当的透明材料和高速摄影流- 可视化技术。 数据来自小型猪、细胞培养和冲击破坏实验， 无论是单独的还是作为一个整体，都将在一个迭代过程中使用， 改进每类实验的设计和解释。