Developing Physics-Based Virtual Simulation Technology for Natural Orifice Transl

描述（由申请人提供）：开发基于物理的自然孔经腔内窥镜手术（NOTES） NOTES是一种新兴的革命性手术范例，被视为腹腔镜手术的自然继承者，其中使用通过嘴，肛门或阴道等自然孔插入的柔性内窥镜通过穿孔内脏（胃，结肠或阴道）进入内部器官；不能在身体表面留下任何切口。这种“无疤痕”手术不仅会带来更好的美容效果，而且还能减少伤口感染和切口疝，以及手术压力、术后不动和疼痛。然而，动物研究显示了严重的手术困难和术后并发症。因此，当前对NOTES的热情不应超过对实现这种新技术的谨慎态度。在美国将NOTES安全地引入人体之前，必须克服其发展的几个基本障碍，包括：(1)发现进入腹腔内器官的最佳技术；(2)确保通过内窥镜将气体（空气或二氧化碳）泵入体腔（这称为气腹，通过称为充气的过程实现）时腹部内的压力不会上升到危险水平或不会泄漏到胃肠道，以增加工作量；(3)保持体腔内的空间定向；(4)接近完美地闭合胃壁穿刺部位（胃切开术闭合）；（五）预防感染；(6)腹膜内出血的控制；(7)开发新的仪器和(8)新的训练方案。目前的范例是基于测试猪模型，这是耗时的，资源密集的，并且严重限制了可以测试的可能替代方案的数量。为了大大加快NOTES程序和设备的发展，我们建议开发第一个基于虚拟现实（VR）的NOTES模拟器，具有视觉和触觉（触摸）反馈。虽然基于vr的模拟器用于腹腔镜手术和胃肠道内窥镜检查，但没有用于NOTES。现有技术不足以模拟NOTES，必须克服胃肠道内窥镜检查或腹腔镜手术中没有遇到的主要技术障碍。这些障碍中最重要的包括：(1)基于物理实验的多层中空器官（如食道、胃、肠、直肠和阴道）的逼真建模；(2)柔性手术工具与软组织相互作用的模拟；(3)基于物理的技术，以确保气腹的有效性和胃切开术闭合的完整性；(4)开发逼真的界面。本课题的目的是克服这些初步的挑战，开发出第一个基于物理实验和手术经验的VR-NOTES模拟器，并对手术并发症的生理后果做出反应。模拟器必须经过广泛的验证才能在临床环境中使用。一个多学科团队汇集了基于物理的医学模拟、生物力学器官建模、人因工程、介入胃肠病学、腹腔镜和妇科外科等方面的专业知识，在一个为期4年的R01研究项目中实现了以下具体目标：SA1)将最新的3D解剖模型与基于物理的组织变形模型相结合，以模拟柔性手术工具与NOTES过程中发生的详细变形器官模型的相互作用；SA2)整合在SA1中生成的计算模型和实验数据，并开发虚拟NOTES阑尾切除术（阑尾切除）模拟器的原型，该模拟器包含手术并发症的生理后果，并允许比较替代手术程序和设备；和SA3)验证计算模型和SA2开发的VR-NOTES模拟器的有效性。

DESCRIPTION (provided by applicant): Developing Physics-Based Virtual Simulation Technology for Natural Orifice Translumenal Endoscopic Surgery (NOTES) NOTES is an emerging revolutionary surgical paradigm, being viewed as a natural successor of laparoscopic surgery, where internal organs are accessed by perforating the viscera (stomach, colon or vagina) using a flexible endoscope inserted through natural orifices such as the mouth, anus or vagina; without making any incisions on the surface of the body. Such "scarless" procedures would not only lead to better cosmetic results but also enhance the prospects of decreased wound infections and incisional hernia, as well as operative stress, postoperative immobility and pain. However, animal studies have shown serious interoperative difficulties as well as post operative complications. Hence, the current enthusiasm regarding NOTES should not overtake a cautioned approach to the implementation of this new technique. Before NOTES can be safely introduced to humans in the United States several fundamental barriers to its development must be overcome including (1) discovering optimal techniques for accessing the intra-abdominal organs; (2) ensuring that the pressure inside the abdomen does not rise to dangerous levels or there is no leakage into the GI tract when gas (air or CO2) is pumped into the body cavity (this is known as pneumoperitoneum and is achieved through a process known as insufflation) through the endoscope to increase work volume; (3) maintaining spatial orientation inside the body cavity; (4) achieving near perfect closure of the puncture site in the gastric wall (gastrotomy closure); (5) prevention of infection; (6) control of intra-peritoneal hemorrhage; (7) developing novel instrumentation and (8) novel training regimens. The current paradigm is based on testing porcine models which is time consuming, resource intensive and severely delimits the number of possible alternatives that can be tested. To vastly accelerate the development of NOTES procedures and devices, we propose to develop the first virtual reality (VR)-based NOTES simulator with both visual and haptic (touch) feedback. While VR-based simulators exist for both laparoscopic surgery and gastrointestinal endoscopy, none exists for NOTES. Existing technology is inadequate for NOTES simulation and major technological hurdles - not encountered in GI endoscopy or laparoscopic surgery - must be overcome. The most significant of these hurdles include (1) realistic modeling of multilayered hollow organs (e.g., esophagus, stomach, intestines, rectum and vagina) based on physical experiments; (2) simulation of the interaction of flexible surgical tools with soft tissues; (3) physics-based techniques of ensuring the effectiveness of pneumoperitoneum and the integrity of gastrotomy closure and (4) developing realistic interfaces. The aim of the present proposal is to overcome these preliminary challenges and develop the first VR-NOTES simulator which is firmly based on physical experiments and surgical experience and is responsive to physiological consequence of surgical complications. The simulator must undergo extensive validation before it can be used in a clinical setting. A multidisciplinary team with collective expertise in physics-based medical simulation, biomechanical organ modeling, human factors engineering, interventional gastroenterology, laparoscopic and gynecologic surgery has been assembled to achieve the following specific aims in a 4-year R01 research project: SA1) To combine the latest 3D anatomical models with physics-based tissue deformation models to simulate the interaction of flexible surgical tools with detailed deformable organ models that occur in NOTES procedures; SA2) To integrate the computational models and experimental data generated in SA1 and develop the prototype of a virtual NOTES appendectomy (appendix removal) simulator which incorporates physiological consequence of surgical complications and allows comparison of alternate surgical procedures and devices; and SA3) To establish the validity of the computational models and the VR-NOTES simulator developed in SA2.