Task-Based Design, Modeling, and Telemanipulation Assistance of Dexterous Robotics for Confined Spaces and Remote Intervention

Abstract

The evolution from open surgery to laparoscopic surgery or minimally invasive surgery to robot-assisted minimally invasive surgery to the natural orifice and single port access surgery required more dexterous tools. The possible solutions to achieving such dexterity are using continuum robots and wire-actuated multi-articulated devices. As surgery evolved from open to minimally invasive surgery (MIS), surgeons became challenged with perception barriers due to not holding the tools with their hands and the constrained visualization inherent to minimally invasive surgical access. Many robotic telesurgical systems in MIS have been developed to improve dexterity, hand-eye coordination, and sensation. However, telemanipulation assistance for remote trauma care interventions is relatively unexplored. Moreover, the current paradigm of robot-assisted minimally invasive surgery lacks a set of systematic methodologies to quantitatively compare different manipulator designs and evaluate different kinematics configurations of the dexterous devices for robotic telesurgical systems. Such comparative approaches are important during the design stage for analyzing, characterizing, and making an informed decision between various design alternatives. This dissertation aims to address these challenges in the areas of design, modeling, and telemanipulation assistance. We first explore the feasibility of the identification of a robotic-palpation-assisted remote landmark (the cricothyroid membrane) for cricothyrotomy. Using a cricothyrotomy training simulator, we evaluated several telemanipulation alternatives for in-situ remote localization of the cricothyroid membrane through a small user study. The preliminary results show that the accuracy of remote landmark identification is improved when the user is aided with visual and force cues. Next, we address the challenge associated with the design and performance assessment of robotic telesurgical manipulators for operation in confined spaces. Unlike most works in the literature, we propose an approach for comparing design alternatives by considering the spurious motions along the length of the manipulator in lieu of existing approaches, looking at only the end-effector dexterity measures. We validate our proposed approach through two different illustrative simulation case studies. The dissertation further explores the design and performance assessment of continuum robots since they are increasingly becoming candidates for robotic architecture for surgical intervention. We present some geometrical insights for analyzing the kinematic singularity of continuum robots to improve the path planning and control of such dexterous devices. We also discuss the notion of safety zones around the nominal kinematic singular configurations to produce designs and paths that guarantee singularity-free performance despite norm-bounded deflections in configuration space. Lastly, we explore how force and motion transmission losses affect the minimal motion resolution at the end-effector of wire-actuated robots. We present a modeling framework that can be used at the design stage to evaluate the effects of internal transmission losses. Considerations of modeling the hysteresis effects of end-effector motion are used to define a performance measure that quantifies the quality of a given design within a workspace. We also discuss how multi-wire-driven wrists cannot be compared using conventional Jacobian-based performance measures because they disregard the wire-tension states. We discuss how to obtain the manipulability of multi-wire-driven wrists by manipulating conventional measures. The proposed methodology can guide the design of wire-actuated robots in selecting wire parameters, choosing wire arrangements, and determining their effects on the expected uncertainty. We believe the contributions presented in this dissertation have provided preliminary insights on the feasibility of robotic assistance for remote interventions and have provided design and modeling insights in the form of performance measures and geometric interpretations of singularities that can be used to guide the design and path planning of dexterous surgical devices.