| While arthroscopic surgery has many advantages over traditional surgery, this minimally invasive technique is not often applied to the hip joint. Reasons for this include the complexity of navigating within the joint, the difficulty of correctly placing portal incisions without damaging surrounding neurovascular structures, and the deep, tight geometry of the hip joint. This thesis outlines completed work on a computer-aided navigation system to address the challenges of arthroscopic hip surgery. Our computer-aided system helps to navigate in the hip joint during arthroscopy by: (1) tracking the tool position with a linkage of encoders, and (2) displaying 3D computer graphics to indicate the tool position relative to the patient anatomy.; The encoder linkage for position tracking was created as a kinematically redundant linkage, with eight degrees of freedom, for increased flexibility. An initial linkage prototype was created and tested. Based on the testing results, a second linkage was created with improved accuracy performance. Using the encoder linkage position information, the visual interface generates images of the patient's hip joint and the surgical tools in order to supplement the restricted view from the arthroscopic camera.; A study of user performance was completed to verify the effectiveness of this computer-aided system for hip arthroscopy. Ten participants completed a basic navigation task with and without the assistance of the computer-aided system and determined that the computer-aided system could reduce task completion time by 38% and tool-path length by 72%. A decrease in task time translates to a faster surgical procedure, and a decrease in path length could decrease patient tissue damage.; A study of the tracking error of the encoder linkage was performed. Two and three-dimensional simulations of the linkage were created, including error in the rotational joints. Multiple linkage endpoints were averaged to obtain a lower position error. Averaging and curve fitting techniques were then applied to the physical encoder linkage for error testing. An error reduction was seen for each numerical technique, with the largest reduction being a 45% decrease in tracking error with a linear curve fitting technique.; Finally, the visual interface was improved to consider the spatial challenges of navigation. In order to reduce the cognitive load while using our system, we have created a global map of the hip joint which displays the viewing direction of the other display windows. In this way, the multiple views of patient anatomy are organized to provide optimal navigation information to the user. |
