Robotic colonoscopy: can high fidelity simulation optimize robot design and validation?

This paper presents the use of a simulation environment as an accurate, ethical, and sustainable alternative to testing robotic prototypes in animal models and simplified phantom models, specifically developed for robotic colonoscopy devices inside the human colon. A virtual simulation of the locomotion mechanism of a prototype robotic colonoscope and the colon was created in Ansys, and robot/colon experiments were conducted on different colon surfaces to validate simulation results. The successfully simulated propulsion force generated by the prototype produced an RMSE of 7% when compared at the optimal operating condition of the device, and 25-30% when compared to a full range of device velocities. The larger RMSE is due to physical phenomena that were not present in the simulation due to the constraints applied. The simulation, however, allowed evaluation of difficult quantities to measure in a real world setting such as the normal interaction force between the device and tissue wall, and stress distribution across the locomotion mechanism, as well as a phenomenon of oscillating propulsion force resulting from the device design. This work demonstrates feasibility of using finite element simulation to shape the design and optimization of a robotic colonoscope and understands its interaction with complex human anatomy.