Department of Biodesign, Institute of Biomaterial and Bioengineering, Tokyo Medical and Dental University



High-functional End-effector for Surgical Forceps and Robotics

To overcome some of the difficulties encountered in minimally invasive surgery, we are investigating a new mechanism for surgical instruments and robotics that can realize multiple degree of freedom motion and function inside the patient body.

Least-Incision Transformable End-effector (LITE) mechanism

Nowadays, there is increasing demand for thinner instruments for endoscopic surgery because such instruments can reduce the invasiveness and improve the application of endoscopic procedures. However, the thinner the instruments, the smaller are the end-effectors. This severely limits their functionality, leading to increased difficulty for grasping organs; furthermore, there is increased risk of organ damage because of the sharpness of the tip.

To solve this problem, we developed a novel Least-Incision Transformable End-effector (LITE) mechanism for forceps that has a small diameter but can be transformed into a larger end-effector after being inserted in the body. This mechanism will eliminate the limitation of the size of ports and instruments, and it will enable surgeons to use forceps with end-effectors that are larger than the port size.

Instruments replacement is another problem in laparoscopic surgery because it is time consuming task in comparison with open surgery. We developed multiple-functionality LITE forceps - called two-way LITE forceps - which can be used as two different-sized graspers through transformation of their end-effector, eliminating the need for switching. This instruments is expected to be highly useful especially in robotized laparoscopic surgery in which the instruments switching is complex and time consuming.

Related publications

Yuki Yamamoto, Ryoichi Nakamura, Two-way least-incision transformable end-effector forceps for robot-assisted surgery, ROBOMECH Journal, 2015, 2:3

Takahiro Abe, Ryoichi Nakamura, Two-way LITE mechanism: least-incision transformable end-effector (LITE) mechanism for two size graspers on endoscopic forceps, The First CIRP Conference on Biomanufacturing (CIRP-BioM 2013), Tokyo, March 4-6, 2013, Procedia CIRP Volume 5, 2013, Pages 137-140

T. Abe, H. Nakaji, and R. Nakamura, Development of the Bending Mechanism for Forceps with Least-Incision Transformable End-Effector Mechanism for Endoscopic Surgery: Development of the Operating Interface and In Vivo Experiment, IEEE International Conference on Biomedical Robotics and Biomechatronics (BioRob2012), Rome, Italy, June 24-27, 2012, Proceedings p.919-923

Hiroaki Nakaji, Ryoichi Nakamura, Miniturization of least-incision transformable end-effector mechanism for forceps for endoscopic surgery, 25th International Congress on Computer Assisted Radiology and Surgery (CARS2011), Berlin, Germany, June 22-25, 2011, Int J of CARS, 6(suppl1):S241-2, 2011

Hiroaki Nakaji, Ryoichi Nakamura, Least-Incision Transformable End-Effector Mechanism for Forceps for Endoscopic Surgery, Proc. of 5th International Workshop on Medical Imaging and Augmented Reality MIAR2010, beijing, China, Sept. 19-20, 2010, Lecture Note in Computer Science 6326:276-285, 2010

Multi-DOF forceps and ultrasonically activated device

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