Kinematic Optimization of a 2-DOF Spherical Mechanism for a Minimally Invasive Surgical Robot

Lum, M. (2004) Kinematic Optimization of a 2-DOF Spherical Mechanism for a Minimally Invasive Surgical Robot. Masters thesis, University of Washington.

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In the late 1980s and early 1990s minimally invasive surgical (MIS) techniques revolutionized the way in which a significant number of surgical interventions were performed. Throughout the 1990s technological advances allowed for the development of a generation of robot manipulators for MIS procedures. While revolutionary, these first generation manipulators were large and cumbersome. By analyzing and optimizing a spherical mechanism designed specifically for MIS this thesis lays the foundation upon which a next generation surgical manipulator will be designed. The kinematics of a 2-link serial and a 5-link parallel, 2 degree-of-freedom mechanisms is developed. Further, the workspace requirements are defined based on surgical measurements taken during actual MIS animal procedures. Using preliminary mechanical design practical joint limits are established. A scoring criterion that takes into account average performance, a guaranteed minimum performance and proportionality to mechanism stiffness is defined using mechanism isotropy as the underlying metric. An overall optimization is performed for both serial and parallel configurations are performed. Adjustable passive aluminum mock-ups were designed and fabricated for experimental evaluation by surgeons of both serial and parallel combinations. From the experimental evaluation it was determined that the proper configuration should be two or more serial manipulators. The kinematic optimization shows that the best design of serial manipulator is 74 for Link1 and 60 for Link2. The results of this research are used in the design of a new surgical robotic system that will save critical space around the patient on the operating table, provide the surgeon with more dexterity than traditional MIS tools, and have the dynamic bandwidth to support for a force-feedback surgeon interface.

Item Type: Thesis (Masters)
Subjects: C Surgical Robots > C Surgical Robots(General)
C Surgical Robots > CA Robotic Control
D Haptics
Divisions: Department of Electrical Engineering
Depositing User: Tim Brown
Date Deposited: 28 Jul 2015 17:36
Last Modified: 28 Jul 2015 17:36

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