Development of advanced quantitative tools for laser radiation safety evaluation in laser urology

激光碎石术是治疗尿路结石最常见的方法。在这个过程中，一个小型的柔性内窥镜被引入尿路到结石的位置。光纤穿过内窥镜，尖端放置在结石附近。高能激光脉冲通过光纤传输到尖端。传输到结石上的激光能量将结石分解成可以通过尿路的小碎片。最近，高功率激光系统已经被创造出来，使这一过程变得更容易，缩短了手术时间，并产生了更小的碎片。然而，来自这些高功率激光的能量会转化为热量，可能会损害肾脏和其他组织。FDA和公共卫生界目前还没有标准的监管科学工具来评估激光碎石设备的安全性。该项目的目标是开发先进的工具，供行业、研究人员和监管机构使用，以评估来自这些激光的加热，以提高未来设备的安全性。该项目将进行计算机模拟和实验室实验，以确定不同激光特性对加热的影响。该项目将创建一个数据库来识别安全功率限制，并创建用于评估新设备的指导文档。它还将涉及在监管科学方面培训未来的科学家和工程师，并就这些影响对医生和医学生团体进行教育。该项目将通过减少这些过程中严重并发症的风险来支持公众健康，并引入安全使用方案。激光碎石术是尿路结石最常见的干预措施，激光纤维通过内窥镜传递脉冲激光能量，导致结石碎裂。最近引进的高功率激光系统扩大了激光碎石术的能力。然而，较高的激光功率存在使肾盏液和组织过热的风险。各种物理、生物和操作者因素对这种热效应的影响尚不清楚。此外，热损伤对这些组织的生物后遗症还没有完全确定。FDA和公共卫生界缺乏标准的测试工具、测试方案和指导文件来评估这些技术的激光辐射安全性。该项目的目标是开发先进的定量调控科学工具，以评估激光碎石过程中光热对尿路的影响，并提高未来设备的安全性。激光碎石的计算有限元模型将被用来模拟激光加热的物理过程，以及激光、冲洗和重力诱导的尿路内液体流动，以确定热和压力的时空分布。这些模型将包括生物流体和组织的真实参数。这些模型将用于模拟激光碎石术的临床相关情景，以评估和预测对组织的热和压力效应，并将为产生生物效应所需的暴露参数的相关限制定义一个数据库。最后，将制作指导文件，用于评估未来的设备和曝光场景。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Laser lithotripsy is the most common procedure to treat urinary stones. In this procedure, a small flexible endoscope is introduced up the urinary tract to the location of a stone. An optical fiber is passed through the endoscope and the tip is placed near the stone. High-energy laser pulses are delivered through the optical fiber to the tip. The laser energy transmitted to the stone breaks it into small pieces that can pass through the urinary tract. Recently, high-power laser systems have been created that make the procedure easier, shortening operating time and producing smaller fragments. However, the energy from these high-power lasers turns into heat that can damage kidney and other tissues. The FDA and the public health community do not presently have standard regulatory science tools for safety evaluation of laser lithotripsy devices. The objective of this project is to develop advanced tools to be used by industry, researchers and regulatory groups to evaluate heating from these lasers to improve the safety of future devices. This project will perform computer simulations and lab experiments to identify how heating is impacted by different laser characteristics. The project will create a database to identify safe power limits, and guidance documentation for evaluating new devices. It will also involve training future scientists and engineers in regulatory science, and educating physician and medical student groups on these effects. The project will support public health by reducing the risk of serious complications during these procedures and introduce protocols for safe use.Laser lithotripsy is the most common intervention for urinary stones, where a laser fiber is passed through an endoscope to deliver pulsed laser energy causing stone fragmentation. The recent introduction of high-power laser systems has expanded the capabilities of laser lithotripsy. However, higher laser power presents a risk of overheating the calyceal fluid and tissue. The impact of various physical, biological, and operator factors on this thermal effect is unknown. Furthermore, the biological sequelae from thermal injury to these tissues are not fully characterized. The FDA and public health community are lacking standard test tools, test protocols and guidance documents for laser radiation safety evaluation of these technologies. The objective of this project is to develop advanced quantitative regulatory science tools to evaluate photothermal effects to the urinary tract during laser lithotripsy and improve the safety of future devices. A computational finite-element model for laser lithotripsy will be developed to simulate physical processes of laser-induced heating, as well as laser, irrigation, and gravity induced fluid flow within the urinary tract to determine the spatiotemporal distributions of heat and pressure. The models will include realistic parameters of the biological fluids and tissues. The models will be used to simulate clinically relevant scenarios of laser lithotripsy to assess and predict thermal and pressure effects to the tissues, and a database will be defined for relevant limits of the exposure parameters required to produce bioeffects. Finally, guidance documents will be produced for evaluating future devices and exposure scenarios.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.