Developing a Computerized Training Tool for Cryosurgery

描述(申请人提供)：冷冻外科是通过冷冻来破坏不需要的组织。尽管微创冷冻外科的设备和技术不断发展，但现代冷冻外科往往不能最大限度地对靶区进行冷冻破坏，同时将对周围组织的冷冻损伤降至最低。在这里，最重要的困难之一--可能也是需要克服的不那么直观的障碍--是冰冻区域的设计和生成，使其与靶区的形状和冷冻手术成功的既定标准充分相关。该项目侧重于为外科医生、医学研究人员和临床器械开发人员规划和创建最佳3D热场的医学培训和教育。 在这个项目中开发了一个计算机化的培训工具，目的是缩短临床医生的学习曲线，减少实践时间，能够对“假设”情景进行案例研究，并能够通过冷冻外科数据库重新评估过去的临床程序。虽然培训工具是为一般目的而设计的，但由于其高度的临床相关性，因此特别关注前列腺冷冻外科。培训工具由三个模块组成：数据库、模拟器和导师；每个模块的开发代表着整个研究计划的一个具体目标。该数据库包括三种类型的数据集：(I)从超声等成像设备获得的体积图像，(Ii)重建的3D靶区模型，以及(Iii)外科手术结果，取决于特定的手术参数，如冷冻探头的数量和类型、冷冻探头的布局、冷冻探头的冻结能力以及由此产生的温度场历史。该模拟器使用标准的超声波技术模拟生物热传递过程及其成像。基于模拟的过程，导师交互地指导学员确定最佳的低温探头布局。辅导员可用于规划未来的程序或重新评估过去的案例，同时进一步增加数据库的大小。 与NIH计划公告(PA)PAR-07-344--在“手术和虚拟工具”这一特定领域--一致，该项目集成了用于模拟手术过程的计算技术，包括冷冻特有的成像效果，以及对临床治疗区域的生物热传递过程的预测。重点是低温外科数据库设计、数据检索、可视化和图形界面，其中数据库包括成像数据、目标区域的几何建模、低温设备特性和热场历史。该项目利用生物传热的快速模拟技术，以及最近开发的用于冷冻手术的计算机化计划的算法。通过将类似的方法应用于外科中的其他热模式，如聚焦超声、微波、激光探头和其他多源加热元件，这一培训工具的更广泛影响可能远远超过其在冷冻外科的具体应用。

DESCRIPTION (provided by applicant): Cryosurgery is the destruction of undesired tissues by freezing. Despite the continuous development of devices and techniques for minimally invasive cryosurgery, modern cryosurgery frequently falls short of maximizing cryodestruction to the target region, while minimizing cryoinjury to the surrounding tissues. Here, one of the most significant difficulties - and probably the less intuitive obstacle to overcome - is the design and generation of a frozen region to adequately correlate with the shape of the target region and established criteria for cryosurgery success. This project focuses on medical training and education associated with planning and creation of the optimal 3D thermal field for cryosurgery, for the benefit of the surgeon, the medical researcher, and the clinical instrumentation developer. A computerized training tool is developed in this project, the objectives being to shorten the clinician's learning curve, reduce practice time, enable case studies of "what-if" scenarios, and to enable revaluation of past clinical procedures via a cryosurgery database. While the training tool is designed for general purposes, due to its high clinical relevancy, a particular attention is given to prostate cryosurgery. The training tool consists of three modules: database, simulator, and tutor; the development of each represents one specific aim of the overall research plan. The database consists of three types of datasets: (i) volumetric images obtained from an imaging device such as ultrasound, (ii) reconstructed 3D target region models, and (iii) surgical- procedure outcomes, subject to specific surgical parameters such as number and type of cryoprobes, cryoprobe layout, cryoprobe freezing capabilities, and the resulting temperature field history. The simulator imitates the bioheat transfer process and its imaging with a standard ultrasound technique. Based on the simulated process, the tutor interactively guides the trainee to identify the optimal cryoprobes layout. The tutor may be used for planning future procedures or reevaluation of past cases, while further increasing the size of the database. Consistent with NIH Program Announcement (PA) PAR-07-344 - in the specific area of "Surgery and Virtual Tools"- this project integrates computational techniques for simulation of the surgical procedure, including the imaging effects unique to freezing, and predictions of the bioheat transfer process in the clinically treated area. Emphasis is placed on cryosurgery database design, data retrieval, visualization and graphical interfaces, where the database includes imaging data, geometrical modeling of the target region, cryodevice characteristics, and thermal field history. This project utilizes rapid simulation techniques for bioheat transfer, and recently developed algorithms for computerized planning of cryosurgery. The broader impact of this training tool can potentially far exceed its specific application to cryosurgery, by applying similar methodology to other thermal modalities in surgery, such as focused ultrasound, microwave, laser probes, and other multi-source heating elements.