Page 163 - Flexible Robotics in Medicine

CHAPTER 6

Handheld flexible robot with concentric

tubes aiming for intraocular procedures

Benedict Tan, Liao Wu and Hongliang Ren
Department of Biomedical Engineering, National University of Singapore, Singapore

As intraocular surgery progressed, the tools in use have shrunk in size, from 20- to 25-
gauge and beyond. The reduction in light intensity caused by this has pushed light pipe
advancement in the direction of brighter and brighter light sources. Despite these advances,
the rigid nature of regular light pipes still limits the range of illumination, especially when
dealing with ciliary bodies. This can be overcome by using a concentric tube robot to build
a steerable light pipe. Such a device is useful in solving issues of orientation and alignment
faced by the surgical platforms being developed or adapted for intraocular surgery, by
supplying end-effector intraocular dexterity. We propose a novel flexible robot design with
a concentric-tube motion generation mechanism to make them more viable for intraocular
procedures. The principles behind the actuation design were identified and modified with
priority placed on compactness and workspace constraints for intraocular surgery. A
threedegrees-of-freedom handheld light pipe steering guide prototype with a suitable tube
configuration has been proven to supply more excellent maneuverability compared to an
ordinary light pipe. After the optimization of tube parameters and a kinematic model, the
application as a light pipe was further evaluated.

6.1 Introduction

We propose an innovative handheld flexible robot design with telescoping concentric tubes
for intraocular procedures. Specifically, its viability in intraocular light pipe steering will be
explored. As intraocular surgery has progressed, the tools in use have shrunk in size, from
20- to 25-gauge and beyond. The reduction in light intensity caused by this has pushed
light pipe advancement in the direction of brighter and brighter light sources. Despite these
advances, the rigid nature of standard light pipes still limits the range of illumination,
especially when dealing with ciliary bodies. This can be overcome by using a concentric
tube robot (CTR) to build a steerable light pipe.

Flexible Robotics in Medicine.
DOI: https://doi.org/10.1016/B978-0-12-817595-8.00006-7 149
© 2020 Elsevier Inc. All rights reserved.