Surgical Robot with Variable Remote Center of Motion Mechanism Using Flexible Structure

[+] Author and Article Information
Sho Yoshida

Former graduate school student, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo 101-0062, Japan

Takahiro Kanno

Assistant Professor, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University

Kenji Kawashima

Professor, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University

1Corresponding author.

ASME doi:10.1115/1.4039396 History: Received July 05, 2017; Revised January 25, 2018


In this paper, a RCM mechanism for holding a robotic forceps that facilitates adjustment using a flexible structure is proposed. The flexible structure is designed and manufactured with polypropylene-like resin material using a 3D printer. Super elastic NI-Ti rods are inserted in the structure to have elasticity for bending and have rigidity for twisting. The structure achieves pitch motion around the pivot point with two pneumatic cylinders. One cylinder drives the position and the other cylinder controls the bending radius of the structure. Therefore, the location of the pivot point can be variable. This allows easier adjustment of the pivot point before or during operation. The holder robot including the mechanism has four degree of freedoms (DOFs) in total, consisting of the pitch, a rotation around yaw axis, a translation in the direction of forceps insertion and a rotation of the forceps. Pneumatic rotary actuators are used for rotations and a cylinder is used for the translational motion. The model of the flexible structure is derived experimentally to design a controller for the pitch motion. A pneumatically-driven robotic forceps is mounted on the holder to construct a master-slave control system. Experimental results show that the proposed control law achieves the desired rotational pitch motion. We compare the holder with a rigid link RCM holder and confirm the robustness of the proposed holder for variable pivot point. Finally, the effectiveness of the system is confirmed with suturing tasks a using phantom tissue.

Copyright (c) 2018 by ASME
Your Session has timed out. Please sign back in to continue.






Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In