Page 92 - Flexible Robotics in Medicine

CHAPTER 4

Flexible steerable manipulator utilizing

complementary configuration of

multiple routing grooves and ball joints

for stable omnidirectional bending

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1
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1
Denise Ying , Darren Poh , Li Ting , Lui Marius , Vanessa Tiew ,
2
Zion Tsz Ho Tse and Hongliang Ren 1
1 2
Department of Biomedical Engineering, National University of Singapore, Singapore, The University
of York, Heslington, York, United Kingdom
Flexible endoscopic graspers allow for minimally invasive diagnostic biopsies and surgical
procedures. Current surgical forceps usually have passive configurations and are thus difficult
to manipulate around corners and in curved trajectories during endoscopic procedures. Our
aim is to produce a steerable endoscopic manipulator that has forceps with a bendable
omnidirectional neck so that it can navigate curved spaces. We reconfigure hollow cylindrical
segments with grooves and ball joints to allow stable omnidirectional bending of large angles,
which allows the full prototype to be more compact by routing cables to extend axially
through grooves instead of threading holes. This enables more straightforward navigation of
contours in body cavities and a more excellent range of motion and application of the end
effector to manipulate body tissues. This prototype is intended for use in conjunction with
endoscopes to conduct biopsies and surgical procedures. We investigate specifications, patent
search, and prior art and focus on the rationale aspects of the design.

4.1 Introduction

Endoscope insertion [1 23] into an orifice of a patient allows for visual inspection and
minimally invasive procedures [6 8] such as biopsies. Endoscopes range in size from a length
of around 0.6 m and a diameter of around 5 mm for smaller cavities like the nasopharyngeal
cavity to a length of over 1 m with a diameter of around 13 mm for the lower gastrointestinal
tract [1,3,9,10]. The distal end often consists of a camera and light source for illumination as
well as a lumen which runs through the entire length of the endoscope. This lumen is used for
the insertion of endoscope accessory instruments (EAIs) to facilitate small procedures such as

Flexible Robotics in Medicine.
DOI: https://doi.org/10.1016/B978-0-12-817595-8.00004-3 77
© 2020 Elsevier Inc. All rights reserved.