Grant: Discovery Grants Program - Individual

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.