Colonoscopy simulator with enhanced haptic realism and visual feedback

This paper presents the KAIST-Ewha colonoscopy simulator II with increased haptic fidelity as well as visual feedback. The colonoscopy simulator includes a specially developed haptic interface and optimized colon models constructed from CT data of actual patients. The colonoscopy simulator provides with enhanced haptic realism, which is made possible by employing a haptic device with decoupled translational and roll force-feedback mechanisms. Manipulation of the colonoscope tip is monitored by four deflection sensors, and triggers computation to render accurate graphic images corresponding to the knob rotation. A photo-sensors unit is developed to simulate jiggling motion which is one of the important colonoscopy skills to fold and straighten the colon. Friction in the haptic device is compensated by using force-torque sensors, and the force-torque profile during simulation is also logged by these sensors. The colonoscopy simulator employs a centerline-based parametric modeling of the colon for fast and accurate collision detection and haptic response between the colon and the colonoscope. The developed Colon Modeler provides with patient-customized colon models, and various training scenarios including rare cases.