MECHANICAL ORGINS OF SHOCK INDUCED BIOEFFECTS IN SHOCK WAVE LITHOTRIPSY

拟议的研究将为解释模式提供基础 就 SWL 产生的机械应力而言，肾损伤的影响 通过聚焦在组织中的冲击波。 应力波直接作用于 冲击波的强度和几何形状，因此影响操作 碎石机。 因此，了解机械之间的联系 冲击波和医疗损伤的影响将允许新的治疗 待制定的指导方针。 该项目的具体目标是： 1. 测量小型猪中引起的机械应力的特性 印第安纳大学 (IU) 实验中的细胞培养模型，以及 与肾损伤的观察结果相关。 这一阶段的研究将 检验以下假设：a) 可测量或可计算的属性 聚焦冲击波施加的机械应力场可以相关 观察 SWL 中冲击波引起的损伤。 2. 确定冲击与组织相互作用引起的应力是否会导致 差速运动，例如剪切和撕裂，会导致机械 生物结构元件的失效。 这项工作旨在测试 b) SWL 冲击波与声波相互作用的假设 组织中的不均匀性会导致应力和差异运动 导致生物结构元件的机械故障。 小型猪肾脏在生长过程中产生的机械应力 碎石术将使用新测试的方法进行测量 植入式薄膜压力传感器。 传感器将测量 直接施加在肾脏上的压力以及压力的改变 波在体内传播时。 生活所承受的压力 SWL 冲击波的细胞也将使用安装的传感器进行测量 直接放入含有细胞培养物的塑料瓶中。 纳入 体内和体外测试中的压力传感器使之成为可能 首次调整体外研究的条件 复制体内环境中经历的机械状态。 冲击波传播的近似理论将用于开发 组织中冲击聚焦的数值模型。 医学物理学的一个重要元素，以前没有被考虑到， 涉及冲击波导致弱结构失效的机制 结构元件，例如膜和薄壁液体填充 船只。 冲击引起失效机制的探索性研究 将进行生物结构的简单机械模型 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、细胞培养和休克失败实验， 无论是单独的还是作为一个整体，都将在迭代过程中使用 改进每种类型实验的设计和解释。

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.