Material Handling System for Robotic Natural Orifice Surgery

Natural orifice translumenal endoscopic surgery (NOTES) is a relatively new surgical approach that uses no external incisions, thereby improving cosmetic outcomes, decreasing overall recovery time, and reducing the risk of external infection. In standard NOTES, flexible endoscopic tools have been used to carry out a variety of surgical procedures in the abdomen. As an alternative, miniature in vivo robots can be fully inserted into the peritoneal cavity and utilized to perform various surgical procedures. These in vivo robots eliminate tool triangulation issues, improve multitasking capabilities, and greatly increase freedom and dexterity when compared to standard endoscopic and laparoscopic tools. One major limitation is that once inserted, the in vivo robots are isolated within the abdomen and cannot send or receive materials to the external environment. The topic of this paper is a material handling system that has been developed to bridge this deficiency. This system features a flexible silicone overtube and an open-loop control system with manual and automatic operation capabilities. The system utilizes the helix of a spring to advance a payload (staples, robotic tool tips, etc.) along the length of the overtube. The system functioned as intended in benchtop and in vivo testing. Minimum bend radius was identified, and a payload was successfully advanced and retrieved through the shuttling system in porcine surgical procedures. NOTES access was achieved via a custom built transvaginal trocar. This paper presents the design and rationale, control strategy, and in vivo testing results for the NOTES material handling system. The system performs as intended based on functional requirements as demonstrated in benchtop and porcine in vivo testing. The control method is robust even when pushed beyond the physical constraints of the system. Collectively, the material handling system provides a simple, repeatable way for an operator to interface with miniature in vivo robots, improving surgical system flexibility while minimizing impact on the duration of an abdominal surgical procedure.