Real-time deformation of colon and endoscope for colonoscopy simulation

Colonoscopy simulation has been increasingly applied as a method of training, which can supplement the traditional patient-based training in recent years. However, the current level of realism of the simulation is insufficient. One of the main difficulties degrading the realism is real-time simulation of colon deformation involving multi-contact interaction with the endoscope.

This paper proposes a novel simulation framework for real-time deformation of the colon and endoscope, using a skeleton-driven deformation method. Cylindrical lattices and a centre-line are employed as the skeletons, and a mass-spring model is applied to the skeletons for the mechanics-based simulation. The centre-line-based collision detection and resolution algorithm is proposed to simulate the interaction between the colon and endoscope. A haptic rendering algorithm using the energy method is proposed to produce feedback force, based on physical interaction between the colon and endoscope.

The proposed simulation framework has been implemented and evaluated in colonoscopy simulation. The simulation results show that the proposed method allows real-time simulation (28 Hz) using a colon model composed of up to 241,440 meshes.

The proposed method allows real-time simulation of colon and endoscope deformation while maintaining a visually plausible result and realistic haptic sensation.