(A) haptic interface for gastrointestinal endoscopy simulation

Abstract

This thesis presents a newly developed haptic interface for gastrointestinal endoscopy simulation. Gastrointestinal endoscopy is a procedure in which the organs of a patient are treated and diagnosed using a long and flexible endoscope. Doctors have to practice this procedure a lot because it is difficult to maintain hand-eye coordination and proper guidance of flexible instruments. Simulators and haptic devices are necessary for such procedural training of doctors. However, previous haptic devices have problems like insufficient workspace and large inertia which makes it difficult to make subtle movements of the tip of the endoscope. Active forces cannot be feedback also. The developed haptic interface incorporates 2-d.o.f, each of which is necessary to describe the movements of an endoscope in actual endoscopy procedures. The haptic interface is divided into a translational motion mechanism which is necessary to implement the insertion movement of the endoscope, a rotational motion mechanism to implement the rotation movement of the endoscope and a folding guide part to prevent the endoscope from bending. The insertion motion of the endoscope is realized by a circular movement in which the endoscope turns around a central axis, which reduces the inertia thereby making it less than the previously developed endoscope, known as Kaist-Ewha Colonoscopy Simulator II. The force feedback in each direction is provided by a wire-driven mechanism. The specifications of the developed haptic interface are evaluated in this article. The haptic interface has larger workspace, higher sensitivity and the maximum attainable force and torque through this endoscope are sufficient to simulate endoscopy procedures such as colonoscopy and ERCP. The force bandwidth is also evaluated through frequency response tests. Finally, Colonoscopy simulation is performed through the developed haptic interface combined with a virtual environment.