Systems and Devices for Minimally Invasive Image Guided Surgery

背景：基于导管的微创心血管介入治疗已被迅速采用，全球每年进行超过1000万例手术。然而，常规方法在导管定位、跟踪和导航方面受到显著限制。这些限制主要是由于器械的长度长、柔韧性、与解剖结构的接合以及从体外进行远程操纵。另一个挑战是，这些手术通常用缺乏3D可视化和解剖背景的2D投影X射线图像来引导。为了解决这些挑战，我们提出了使用一个新的概念：可扩展的电缆驱动的并联机械手（X-CADPAM）。与传统的刚性连杆机器人不同，缆索驱动并联机器人利用缆索进行驱动和定位，因此具有特定的优势：更大的力矩，高有效载荷重量比，以及低制造和装配成本。然而，它们需要大的框架来锚缆，这限制了它们的应用。通过使用可收缩的可扩张框架（例如，在导管内）以允许穿过狭窄的通道，然后一旦到达所需的目标区域就打开，我们可以利用CADPAM的特定益处，同时克服由于其大尺寸而导致的进入限制。目的：本研究计划旨在从根本上研究X-CADPAM并开发：1）适合心血管介入的尺寸的小型化方法; 2）建模其运动学并设计和开发用于其模型识别和位置控制的系统和方法;以及3）应用X-CADPAM概念设计和开发新型成像仪器，克服传统成像设备的局限性，实现完整的图像-导航平台。方法：我们将开发使X-CADPAM小型化的设计，首先是12 Fr（4 mm），然后是6- 9 Fr。我们将设计和开发电缆张紧机制和传感机制，并将所有组件集成到导管中。然后，系统的运动学将建模，自适应跟踪方法将被开发，以允许系统参数识别和鲁棒的位置跟踪和控制。X-CADPAM概念还将用于在进行测量时将超声换能器定位在不同位置，因此，能够实现大视场图像重建。这将有助于创建前瞻性导管和完整的图像引导增强虚拟导航框架。工作的意义：这项研究将提高我们对小型化X-CADPAMS的设计，建模，开发和控制的知识，并将使其应用于目标难以达到的场景。拟议的研究将有助于克服传统的基于导管的介入治疗在转向、跟踪和图像引导方面的局限性。

Background:Minimally invasive catheter-based cardiovascular interventions have been rapidly adopted and more than 10 million procedures are performed each year worldwide. However, conventional methods suffer from significant limitations in catheter positioning, tracking, and navigation. These limitations are primarily due to the device's long length, flexibility, engagement with the anatomy, and their remote manipulation from outside the body. A further challenge is that these procedures are typically guided with 2D projection x-ray images that lack 3D visualization and anatomical context. To address these challenges we propose the use of a new concept: expandable cable-driven parallel manipulators (X-CADPAM). Unlike conventional robots with rigid links, cable-driven parallel manipulators utilize cables for actuation and positioning and therefore offer specific advantages: larger workspaces, high payload-weight ratio, and low manufacturing and assembly costs. However, they require a large frame to anchor the cables which limit their applications. By using an expandable frame that can be contracted (e.g., within a catheter) to permit travel through a narrow passageway, and then opened once the desired target area is reached, we can take advantage of the specific benefits of CADPAMs while overcoming their limitation in access due to their large size. Objectives: This research program aims to fundamentally investigate X-CADPAMs and develop: 1) methods for their miniaturization at sizes suitable for cardiovascular interventions; 2) model their kinematics and design and develop systems and methods for their model identification and position control; and 3) applying the X-CADPAM concept to design and develop novel imaging instruments overcoming the limitations of conventional imaging devices and enabling a complete image-based navigation platform. Approach: We will develop designs that enable miniaturization of the X-CADPAM, first to 12Fr (4mm) and then to 6-9Fr. We will design and develop the cable tensioning mechanisms and sensing mechanisms and integrate all components within a catheter. Then the system's kinematics will be modeled, and adaptive tracking methods will be developed to permit system parameter identification and robust position tracking and control. The X-CADPAM concept will also be used to position ultrasound transducers at various locations while making measurements, therefore, enabling a large field of view image reconstruction. This will enable the creation of forward-looking catheters and full image-guided augmented virtuality navigation framework. Significance of the work: This research will enhance our knowledge on the design, modeling, development, and control of miniaturized X-CADPAMS and will enable their application in scenarios where the target is difficult to reach. The proposed research will help overcome the limitations of conventional catheter-based interventions with regards to steering, tracking, and image guidance.