CHS: Small: Collaborative Research: Teleoperation with Passive, Transparent Force Feedback for MR-Guided Interventions

磁共振成像（MRI）是一种广泛使用的诊断工具，为医生提供了自然视觉的显着扩展，提供无与伦比的高清视觉，使软组织病理生理学诊断，病变描绘和治疗监测无需电离辐射。越来越多的医生希望MRI不仅用于诊断，而且用于活检或肿瘤消融等指导程序，以提高准确性。然而，磁共振孔的几何形状迫使医生站在外面，并将运动和力远程传递给内部对患者进行手术的工具。因此，尽管MR提供了优越的成像，触觉却缺失了。为了克服这一缺陷并实现远程呈现，医生需要高保真力反射远程操作系统。MR的强磁场带来了额外的挑战；必须避免铁磁性材料和有电流的电子设备，甚至有色金属也会产生成像伪影，这限制了执行器、变速器和传感器的选择。在这个项目中，pi的目标是通过将实时3D组织成像与身体互动的动觉和力反馈相结合，使医生能够像直接与患者接触一样操作。项目成果有可能直接影响大量人口，因为这里开发的高保真力传输将适用于其他图像引导干预措施，如药物输送和超声波。混合静压传动将适用于（实际上最初是为）交互式人机安全机器人；在使其适应核磁共振引导干预方面取得的进步将使技术成熟，尺寸和成本的减少将有助于将其推向医疗机器人和双边远程操作等其他领域。这项研究代表了机器人、触觉学和介入放射学专家之间的合作。这项工作将建立并扩展一种新型的双边远程操作器，该远程操作器基于流体静力和气动元件，带有滚动隔膜执行器，具有低惯性、被动、高刚度和透明度的独特组合，可以忽略摩擦和间隙，非常适合在MR孔外的医生和内部对患者进行操作的工具之间提供动觉和力反馈，例如，使医生能够感受到组织特性的变化。如果被动遥操作器足够坚硬和轻便，灵敏、灵巧的任务就可以实现。由于MR的特殊限制，MR引导的干预措施是混合传动的一个引人注目的应用，如上所述，MR排除了许多其他技术。本研究解决的一个关键问题是如何将单轴原型的有前途的性能扩展到能够执行核磁共振引导程序的复杂多轴系统。pi将运动学和动态分析与人体工程学的用户测试相结合，以确保它支持直观的运动，并在MR孔的有限空间内提供透明的反馈。他们将通过兼容的传感器和成像基准将远程操作系统的运动与MR图像集成在一起，以提供视觉反馈，并防止意外侵入不需要的区域，而医生则专注于工具尖端的交互。新型力反射传动、运动机构、传感器和软件共同构成了一个具有前所未有能力的网络-人系统。这种远程呈现系统将是一个理想的平台，以扩大对传输透明度为核磁共振引导干预提供的影响的科学理解。

Magnetic resonance imaging (MRI) is a widely used diagnostic tool that provides physicians with a remarkable extension to their natural vision, offering unparalleled high-definition visuals which enable soft tissue pathophysiology diagnosis, lesion delineation, and therapy monitoring without ionizing radiation. Increasingly, physicians would like to use MRI not only for diagnosis but also for guided procedures like biopsy or tumor ablation, for greater accuracy. However, the MR bore's geometry compels the physician to stand outside and transmit motions and forces remotely to tools operating on the patient within. So although MR provides superior imaging, the sense of touch is absent. To overcome this deficiency and achieve telepresence, physicians require a high-fidelity force-reflecting teleoperation system. Added challenges are imposed by MR's intense magnetic field; ferromagnetic materials and electronics with current flow must be avoided, and even non-ferrous metals can produce imaging artifacts, which constrains the choice of actuators, transmissions, and sensors. The PIs' goal in this project is to empower physicians to operate as if they were directly in contact with their patients, by integrating real-time 3D tissue imaging with kinesthetic and force feedback for physical interactions. Project outcomes have the potential to directly affect a large population, because the high-fidelity force transmission developed here will be applicable to other image-guided interventions such as drug delivery and ultrasound. The hybrid hydrostatic transmission will be applicable to (and indeed was initially conceived for) interactive human-safe robots; advances made in adapting it to MR-guided interventions will allow maturation of the technology and reductions in size and cost that will help push it into additional fields like medical robotics and bilateral teleoperation. This research represents a collaboration among experts in robotics, haptics and interventional radiology. The work will build upon and extend a novel bilateral teleoperator based on hydrostatic and pneumatic elements with rolling diaphragm actuators that provides a unique combination of low inertia, passivity, high stiffness and transparency, and negligible friction and backlash, and which is ideally suited to provide kinesthetic and force feedback between a physician outside the MR bore and tools operating on a patient within, allowing physicians to feel tissue property variations, for example. Sensitive, dexterous tasks will be realizable with a passive teleoperator if it is sufficiently stiff and light. MR-guided interventions are a compelling application for the proposed hybrid transmission because of MR's particular constraints, which as noted above rule out many other technologies. A key question this research addresses is how to scale the promising performance of single-axis prototypes to a complex multi-axis system able to perform MR-guided procedures. The PIs will combine kinematic and dynamic analyses with user tests for ergonomics to ensure that it supports intuitive motions and provides transparent feedback while fitting inside the MR bore's constrained space. They will integrate the teleoperated system's motions with MR images via compatible sensors and imaging fiducials to provide visual feedback and prevent accidental intrusion into undesirable regions while the physician focuses on tool tip interactions. Together, the novel force-reflecting transmission, kinematic mechanism, sensors, and software constitute a cyber-human system with unprecedented capabilities. This telepresence system will be an ideal platform to expand scientific understanding of the impact that transmission transparency provides for MR-guided interventions.