Modeling, Calibration, and Intelligently-assisted Telemanipulation of Surgical Continuum Robots
Continuum robots can support complex surgical tasks within deep confined spaces of the body. Such paradigms present surgeons with sensory and surgical scene interpretation challenges that diminish situational awareness. Using these robots in a semi-automated mode of operation may alleviate the cognitive burden of the surgeons. Additionally, these robots have been recently shown able to support two modes of operation including macro-scale and micro-scale motion; thereby possibly enabling in-vivo microsurgical execution and image-based biopsy. The exciting capabilities of continuum robots are unattainable without the availability of accurate kinematic models of these robots. Furthermore, situational awareness augmentation requires methods for reconciling preoperative imaging information with the surgical scene in a way that helps the surgeon in executing surgical tasks safely. These needs and opportunities guide the scope of this dissertation in two broad themes: (i) the augmentation of situational awareness through the use of force-controlled exploration as a means for updating the geometry of a virtual fixture despite possible organ shift/deformation, (ii) an exploration of mathematical frameworks for modeling and calibration of continuum robots when moving in free space at a macro and micro-scale. In Chapter 2, we explore the utility of using force-controlled exploration as a means for updating the registration of an organ to a pre-operative model. Such methods may in the future be used as a means of augmenting other sources of information such as stereo-vision or organ scanning for the purpose of improving registration. In Chapter 3, we present a mathematical framework for calibrating the kinematic model of continuum robots. The derivation of the identification Jacobians for calibration of continuum robots advances the literature, which has been limited to ad-hoc methods that work for limited architectures. In Chapter 4, we investigate methods along the lines of extending calibration modeling to account for cases where continuum robots are used in micro-scale motion generation through equilibrium modulation. These robots present a new concept in continuum robotics, and we develop a simplified kinematic model based on moment coupling effect which lays the foundation to enabling future applications such as image-based biopsy and micro-surgery.