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

激光碎石术是治疗泌尿系结石最常见的方法。在这个过程中，一个小的柔性内窥镜被引入到尿路结石的位置。将光纤穿过内窥镜，并将尖端放置在结石附近。高能激光脉冲通过光纤传送到尖端。传输到结石的激光能量将其破碎成可以通过尿路的小块。最近，高功率激光系统已经被创造出来，使手术变得更容易，缩短了手术时间，产生了更小的碎片。然而，这些高功率激光的能量转化为热量，可能会损害肾脏和其他组织。FDA和公共卫生界目前没有用于激光碎石器械安全性评价的标准监管科学工具。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，以评估这些激光器的加热，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如何影响加热。该项目将创建一个数据库，以确定安全功率限制，并为评估新设备提供指导文件。它还将涉及培训未来的科学家和工程师在监管科学，并教育医生和医学学生团体对这些影响。该项目将通过减少这些手术过程中发生严重并发症的风险来支持公共卫生，并引入安全使用协议。激光碎石术是泌尿系结石最常见的干预措施，其中激光纤维穿过内窥镜以提供脉冲激光能量，导致结石破碎。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、生物和操作员因素对这种热效应的影响尚不清楚。此外，对这些组织的热损伤的生物学后遗症尚未完全表征。FDA和公共卫生界缺乏标准的测试工具，测试协议和指导文件，用于这些技术的激光辐射安全评估。本项目旨在开发先进的定量监管科学工具，以评估激光碎石术期间光热对尿路的影响，并提高未来器械的安全性。将开发激光碎石术的计算有限元模型，以模拟激光诱导加热的物理过程，以及激光、冲洗和重力诱导的尿路内流体流动，以确定热和压力的时空分布。模型将包括生物液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场景，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值定义一个数据库。最后，将为评估未来的设备和暴露场景制作指导文件。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估。

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.