Graduation Semester and Year

2017

Language

English

Document Type

Thesis

Degree Name

Master of Science in Mechanical Engineering

Department

Mechanical and Aerospace Engineering

First Advisor

Panayiotis S Shiakolas

Abstract

The aim of this thesis is to investigate and develop a robotic system capable of a transurethral palpation of any targeted area on the bladder interior wall tissue to determine the biomechanical properties of the tissue considering the urinary tract geometric constraints and to demonstrate the motion kinematics of such robot to achieve a desired robot pose normal to any localized region throughout the bladder workspace. Current technologies have, to varied degree of success, provide approximate, global diagnostics information to bladder tissue elasticity. However, no direct access qualitative methods to measure the bladder tissue properties are known. For this reason, a survey of robotic systems applied to minimally invasive surgery was performed with the aim of repurposing existing robotic systems for bladder elasticity dysfunction diagnostics. The result demonstrated their limitations and a requirement for a procedure specific solution. In the first part, this thesis examines the advantages of flexible robotic manipulators over rigid link robotic manipulators; and the design, actuation and modeling principles of flexible robotic manipulators; the relationship between bladder tissue elasticity and the health condition of a patient. In the subsequent parts, a conceptualized design of the robotic system which comprised of a flexible-continuum module, a rigid tube and tendon actuation mechanism, and a hyper-spherical actuation base was proposed. Furthermore, the Modified Denavit- Hartenberg parameter approach was applied to obtain the robot forward kinematics motion while a close-loop inverse differential kinematics that makes use of a Jacobian relationship between the joint space and the cartesian space to obtain a desired robot pose. Consequently, mechanical stress analyses of the structural components of the flexible-continuum module are provided to determine the fabrication material(s) using FDA approved standards. Finally, structural components of the flexible-continuum module were prototyped using 3D printing technologies to visualize the proposed robot and its function. The results show a proposed robot capable of reaching a desired pose at any targeted location normal to the bladder surface with observable position and orientation errors, throughout the bladder workspace. Also, the evaluation of the flexible-continuum module proves the functionality of coupling rigid- flexible components to obtain structural stiffness while also maintaining dexterity.

Keywords

Flexible, Continuum, Robot, Robotics, Tissue, Diagnostics, Medical, Bladder, Dysfunction, Elasticity

Disciplines

Aerospace Engineering | Engineering | Mechanical Engineering

Comments

Degree granted by The University of Texas at Arlington

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