Design and Experimental Validation of a Master-slave Robotic System for Flexible Ureteroscopy

Flexible ureterostomy (FURS) has been increasingly applied in disease diagnosis and treatment (stone fragment and retrieval, tissue biopsy) inside the urinary tract, and provides advantages in terms of less blood loss, shorter hospital stay, higher stone free rate and lower complication rate. However, the traditional manual FURS procedures are highly skill-demanding and easily lead to fatigue and burnout for surgeons. The improper ergonomics, fragile instruments and limited operation accuracy pose challenges for the further development and patient safety enhancement. To address these issues, this work proposes a master-slave robotic FURS system on the basis of requirement analysis of manual FURS operations. This system mainly consists of a slave manipulator with 3 degrees of freedom (DoFs) to directly control the flexible ureteroscope motions (translation, rotation and distal deflection) and an isomorphic 3-DoF master manipulator to achieve intuitive motion mapping. Both mechanical prototype and control hardware configuration have been implemented, and a proportional joint control strategy has been investigated for motion mapping between the master-slave sides. Phantom experiments have been performed to validate its excellent tracking performance, and animal experiments have demonstrated its efficiency and effectiveness to ease surgeons’ workloads compared with the traditional FURS. The animal experiment indicates that this system can provide a more comfortable operation mode than the conventional manual operation. The proposed robotic system can improve the efficiency and quality of FURS, reduce the operation difficulties, as well as serving as a generalized platform for natural orifice transluminal endoscopic surgery (NOTES) with commercial endoscopes.