Date of this Version
M. Reichenbach, "Gross Positioining Arm for In Vivo Robotic Surgery," Mechanical (and Materials) Engineering - Dissertations, Theses, and Student Research, Aug. 2016.
Laparoendoscopic single-site surgery (LESS) has proven to be beneficial in reducing recovery time, infection, and post-operative pain, but is inherently difficult due to the constraint of a single incision. The difficulties can be mitigated by using in vivo robots that can be inserted through the incision, with multiple arms and a vision system used to accomplish surgical tasks. Once the robot is inserted, it needs to be positioned so that it can focus on the target surgical site. Currently, this is accomplished manually with a table mounted support clamp. This thesis outlines the motivation, design, and evaluation of a proposed 3 degree-of-freedom (DOF) gross positioning arm built to provide automated orientation control of an in vivo surgical robot, enabling it to reach any quadrant of the abdomen without having to stop the procedure and reorient the robot, while also providing enough force and torque to hold the robot steady during surgery. The proposed design is much smaller than current gross positioning arms, which reduces crowding over the patient, while also providing intuitive control to the surgeon. In particular, this thesis proposes a novel control scheme, which provides control of the system without changing control modes. Experimental results from a standard peg-transfer test show the proposed design is capable of operating in all quadrants, while maintaining the stability of the in vivo robot, providing smooth motion as the surgeon operates. Experiments performed by a surgeon at the University of Nebraska Medical Center showed the system provided intuitive control while accessing all necessary quadrants for surgery.
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