Two-way least-incision transformable end-effector forceps for robot-assisted surgery

摘要

In laparoscopic surgery, smaller incisions produce good clinical results for patients. Therefore, there is a great need to develop thinner instruments for use in laparoscopic surgery. However, thinner instruments have smaller end effectors that limit the functionality of the instruments. To address this problem, we previously developed a new type of forceps that uses a least-incision transformable end-effector (LITE) mechanism for graspers of two sizes (i.e., a two-way LITE mechanism), which decreases the instrument exchange frequency and the total procedure time during surgery. Robot-assisted surgery is currently receiving considerable attention. However, instrument exchange during robot-assisted surgery is complicated. The purpose of this study was to develop a new two-way LITE forceps that would be suitable for use in robot-assisted surgery and laparoscopic surgery by being attached to a handpiece to reduce the time and difficulty associated with the instrument exchange during robot-assisted surgery. The experimental results show that the proposed forceps can reduce the total instrument exchange time in a simulated robot-assisted surgery environment, generate sufficient grasping forces to serve as a laparoscopic grasper, and perform switching between its small-grasper and large-grasper modes when operated with one hand using the handpiece. An in vivo experiment was performed on a pig under simulated surgery conditions to evaluate the usefulness of the prototype developed in this study. When operated with a motor drive, the forceps was able to grasp the liver using its large grasper.