EXCIMER LASER PHOTO ABLATION OF ATHEROSCLEROTIC PLAQUE

拟开展的研究主要集中在准分子激光的细节上。 在流体介质存在的情况下与冠状动脉组织的相互作用。 这项研究的目的是了解光消融是如何 通过脉冲准分子辐射在病变动脉中完成 被流场包围的光纤。这些信息是必不可少的。 用于经皮穿刺术中激光能量的优化和控制 激光肛门成形术。 准分子激光作用的机制将由一系列完整的 冠状动脉节段的光物理和光化学测量。 测量将使用准分子波长进行，已经 我们以前的工作表明，可以通过光纤高效地传输 光纤(351 Nm)，并能够实现组织光消融 有生理盐水、氟化钠和血液。这些衡量标准将包括： 1.冠状动脉节段光消融阈值的测定 流体 2.测定香港排放的颗粒物的形成程度 流体介质 3.在气相和液态中释放的光产物的分析 4.光烧蚀过程中的光电子能谱分析 5.光烧蚀时自由基形成程度的测定 自旋陷阱 6.用光声光谱仪测定激光能量散布 拟议的研究计划将带来光谱的全部力量 和现代分析测量方法来确定详细的 对冠状动脉准分子激光消融过程的认识 动脉粥样硬化病变。与以前对准分子的几项研究不同 与心血管组织的相互作用，包括来自我们自己的组织 实验室里，光物理机制的测定将是活跃的 在三个重要的流体场中完成--血液， 生理盐水和血液替代品，氟化钠。这样的实验预计将 对确定最佳激光器至关重要 控制使用准分子激光能量所需的参数 经皮激光血管成形术。

The proposed research is focused on the details of excimer laser light interaction with coronary artery tissue in the presence of a fluid medium. The purpose of the research is to understand how photoablation is accomplished in a diseased artery by pulsed excimer radiation through an optical fiber surrounded by a fluid field. Such information is essential for the optimization and control of laser light energy in a percutaneous laser angoiplasty procedure. The mechanism of excimer laser action will be determined by a full range of photophysical and photochemical measurements on coronary artery segments. The measurements will be made with excimer wavelengths which have been shown by our previous work to be efficiently transmitted through optical fibers (351 nm) and capable of effecting tissue photoablation in the presence of saline, Fluosol and blood. These measurements will include: 1. determination of the photoablation threshold for coronary segments under fluid 2. determination of extent of formation of particulate matter released in fluid media 3. analysis of photoproducts released in both gas and liquid phase 4. analysis of photoemission accompanying photoablation 5. determination of extent of free radical formation on photoablation by spin trapping 6. determination of spread of laser energy by photoacoustic spectroscopy The proposed research program will bring the full power of spectroscopic and modern analytical measurements to the determination of the detailed understanding of the excimer photoablation process in coronary atherosclerotic lesions. Unlike several previous studies of excimer interactions with cardiovascular tissue, including those from our own laboratory, the determination of photophysical mechanisms active will be accomplished in the presence of three important fluid fields - blood, saline and the blood-substitute, Fluosol. Such experiments are expected to be of central importance to the determination of the optimum laser parameters required for the controlled use of excimer laser light energy in percutaneous laser angioplasty.