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Cooperative manipulation of highly articulated and continuum surgical robots in confined spaces

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Title: Cooperative manipulation of highly articulated and continuum surgical robots in confined spaces
Authors: Leibrandt, Konrad Marek Gunter
Item Type: Thesis or dissertation
Abstract: Robotic assisted surgery has been adopted for many minimally invasive procedures. In particular master-slave systems have proven to make surgical procedures more ergonomic and reduce cognitive burden for the surgeon. Manipulation with currently used tools is dependent on pivoting motion at the insertion point which makes them difficult to reach deep seated pathologies through confined spaces. For these procedures alternative instrument designs with increased articulation at the distal end of the tool enable dexterous motion even if the access of the tools needs to be performed through natural orifices in parallel or is constrained to specific access pathways. This thesis investigates intuitive manipulation of novel robotic instruments such as highly articulated tendon-driven tools and concentric tube robots. The developed algorithms ensure that the operator is in full control of the complex surgical systems with a high number of Degrees-of-Freedom (DoF). These algorithms simplify complex system control and enable intuitive manipulation. Constraints of the surgical robot such as motion limits, unstable configurations and collision with the anatomy are safely handled or transparently fed back to the operator. Workspace analysis, path-planning and collision avoidance techniques are combined into a collaborative control and guidance scheme, also known as Active Constraints and Virtual Fixtures, which informs the user about the robots capabilities, and anatomical constraints. It provides haptic and visual cues and can suggest in complex situations alternative access paths. The concept of Implicit Constraints was proposed to algorithmically define guidance based on limited user input, which makes it suitable to be integrated in the normal surgical work-flows. A control architecture was also developed for highly articulated tendon-driven instruments of different DoFs. The instrument control included compensation for non-linear transmission behaviour and was verified through both ex-vivo tissue and in-vivo animal trials. The collaborative manipulation algorithms for concentric tube robots were implemented in a real-time simulation environment and were validated in detailed, realistic user experiments.
Content Version: Open Access
Issue Date: Sep-2017
Date Awarded: Mar-2018
URI: http://hdl.handle.net/10044/1/68593
DOI: https://doi.org/10.25560/68593
Supervisor: Yang, Guang-Zhong
Darzi, Ara
Sponsor/Funder: Imperial College London
Engineering and Physical Sciences Research Council (EPSRC)
Department: Computing
Publisher: Imperial College London
Qualification Level: Doctoral
Qualification Name: Doctor of Philosophy (PhD)
Appears in Collections:Computing PhD theses

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