Page 336 - Flexible Robotics in Medicine

CHAPTER 14

Force sensing in compact concentric tube

mechanism with optical fibers

1
1
2
1
Niam Jen Yang , Tianliang Li , Xiao Xiao , Zion Tsz Ho Tse , Chwee Ming Lim 3
and Hongliang Ren 1
1 2
Department of Biomedical Engineering, National University of Singapore, Singapore, The University
3
of York, Heslington, York, United Kingdom, Singapore General Hospital, Bukit Merah, Singapore

Recent advances in minimally invasive surgery (MIS) have utilized a variety of equipment,
usually in the form of robotics, to aid surgeons during surgical procedures. This involves the
manipulation and navigation of long tools and devices inside the body in such a manner that
causes minimal damage to surrounding tissue structures. A significant limitation of these tools
is that they deprive surgeons of their traditional sense of touch, perception, and dexterity.
Current systems provide visual feedback but lack the force feedback capabilities necessary to
enable surgeons to reduce potential tissue damage. Force sensing capabilities were proposed
for a concentric tube robot, utilizing mounted fiber Bragg grating (FBG) sensors. The system
and software designs were developed along with a kinematic model for control. The FBGs
were fixed onto the robot and calibrated. Experiments were then carried out to determine if the
sensors were sufficiently functional. From the results obtained, the FBGs proved to be highly
sensitive and sufficiently accurate in delivering force readings of the robot tissue interactions.

14.1 Introduction

Robotically enhanced minimally invasive surgical procedures require the use of various pieces
of equipment and prosthetics limited to the intracorporal area of the body. This involves the
manipulation and navigation of tools and devices inside the body in a manner that causes
minimal damage to tissue structures. Due to interior body contours, sensitive tissue, or orifices,
movement of devices within the body is usually complex and requires the careful direction of
surgical equipment along curved surfaces. Once at the surgical site, precise positional control
and orientation of the instrument are necessary to limit tissue damage. Concentric tube robots
(CTRs) are one example of such devices that are equipped to enable navigation through the
body due to their ability for controlled lateral motion [1], the housing of additional tools within
their lumen, and dexterity at surgically equivalent diameters [2].

Flexible Robotics in Medicine.
DOI: https://doi.org/10.1016/B978-0-12-817595-8.00015-8 327
© 2020 Elsevier Inc. All rights reserved.