Graduate Studies


Date of this Version

Summer 8-2012


Mondry, J. M. (2012). Design and Development of a Four Degree of Freedom in Vivo Surgical Robot for Laparoendoscopic Single-Site Surgery. MS Thesis, University of Nebraska-Lincoln.


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Mechanical Engineering, Under the Supervision of Professor Shane M. Farritor. Lincoln, Nebraska: August, 2012

Copyright 2011 Jack Michael Mondry


Recent developments in surgical techniques have allowed procedures to be done using several small incisions rather than a single large incision. Specialized tools and cameras are inserted through the small incisions to manipulate and visualize tissues, as opposed to the direct visualization and manipulation experienced during traditional surgeries. These techniques are categorized as Minimally Invasive Surgery (MIS) and offer the patient many benefits over traditional surgeries including decreased recovery times, lower costs, reduced risk of infection, and more desirable cosmetic results. LaparoEndoscopic Single-Site (LESS) surgery is an attractive subcategory of MIS, requiring only a single small incision. MIS techniques are more beneficial for the patient than traditional surgery but surgeons must operate with unintuitive controls, limited dexterity, reduced visualization, and minimal tactile feedback. Recently, miniature surgical robots have been developed to help overcome the difficulties associated with MIS.

This thesis presents advances in minimally invasive robotic surgery, specifically a miniature in vivo surgical robot for LESS procedures. The robotic platform has two arms, each with four degrees of freedom (DOF) and is capable of manipulating and cauterizing tissue. A unique differential bevel gear arrangement is used to realize a 2-DOF shoulder joint in a minimal package size. The robot is controlled remotely from a surgical user interface which allows the surgeon to operate without direct visualization of the patient, making it possible for the surgeon to be in a different location. To perform surgery, the robot is completely inserted into an insufflated abdominal cavity through a single small incision using a novel insertion device. From this point, the robot can be repositioned to place the operating site within the robotic workspace. Benchtop tests and in vivo procedures were used to demonstrate the capabilities of the robot. The system was shown to exhibit many desirable attributes such as increased workspace, intuitive controls, and minimal size.

Advisor: Shane Farritor