New colonoscopy simulator with improved haptic fidelity

Colonoscopy is a safe and effective procedure to diagnose and treat the large bowel with the help of the flexible endoscope. This paper presents a new colonoscopy training simulator to help trainees practice and acquire the necessary skills and experiences with no risk to the patients and possibly less cost. The simulator includes a specialized haptic interface to transfer force feedback through a long and flexible tube, and graphics algorithms to display the virtual colon realistically while managing the large number of polygons. A new 2-d.o.f. haptic device with folding guides is developed to transmit large decoupled forces of the colonoscopy simulation to the user. The physicians apply a jiggling motion to the colonoscopy tube to advance the scope. This jiggling is an important skill of colonoscopy and is incorporated for the first time by using the new sensor mechanism. A colonoscope handle that shares the look, feel and functions with an actual colonoscope is developed with the necessary electronics inside. The simulator contains controllers to compensate for the inertia and friction effects, and is evaluated by physicians. New graphics algorithms including polygon reduction, navigation and collision detection are developed to compute the deformation and the corresponding reflective force in real-time.     

Design of a vision-guided microrobotic colonoscopy system

In this paper presents a novel design of a microrobotic colonoscopy (MRC) system. The proposed microrobotic colonoscope is an autonomous vision-guided device, which is designed to navigate inside a human colon for the purpose of observation, analysis and diagnosis. It is developed to alleviate the shortcomings in the existing manual colonoscopy procedure, which is generally cumbersome and tedious for the colonoscopist and painful to the patients. The MRC system is divided into three areas, i.e. design of the microrobotic device, path planning and guidance, and offboard control system. A novel design of the microrobot is presented which utilizes a pneumatic mechanism to achieve locomotion and steering. A new concept of clamping the colon wall based on passive vacuum devices is suggested. General mathematical analysis governing the differential steering of the robotic tip is also described. The path planning of the microrobot is carried out based on the sensory fusion utilizing the quantitative parameters derived from the captured images and the tactile sensors. An off-board control system to control the directional movements of the microrobot is explained. The proposed colonoscopy system was tested with physical models and animal colons, and the experimental observations are presented.