Simultaneous physiological motion cancellation and depth adaptation in flexible endoscopy using visual servoing

Flexible endoscopes are used in many surgical procedures and diagnostic exams. They have also been used recently for new surgical procedures using natural orifices called NOTES. While these procedures are really promising for the patients, they are really awkward for the surgeons. In order to assist the surgeon, physiological motion cancellation has been successfully applied on a robotized endoscope in [8]. However, the stability and performance of the involved controller were ensured only on a small working area, thus preventing the surgeon to manually move the endoscope during motion rejection. We propose in this paper to improve the physiological motion rejection despite depth changes due to the manual manipulation of the system. For this purpose, the complete model of the system is developed and an adaptive predictive controller based on depth estimation is proposed. The validity of the approach is demonstrated in in vitro experiments.