Page 182 - Flexible Robotics in Medicine

CHAPTER 7

Tendon routing and anchoring for

cable-driven single-port surgical

manipulators with spring backbones

and luminal constraints

1
1
1
Catherine Jiayi Cai , Seenivasan Lalithkumar , Xinchen Cai ,
2
1
Krishna Ramachandra , Francis Wong and Hongliang Ren 1
1 2
Department of Biomedical Engineering, National University of Singapore, Singapore, National
University Hospital, Singapore
We employ a master-slave architecture with a tendon-driven actuation mechanism to
achieve robotic functionality for the potential application in minimally invasive osseous
tumor removal. We improved tendon routing, anchoring, and fixation for the spring
backbone bending method based on cable-driven principles. We explored different methods
of engineering the tendon guides as well as studied their effects on the flexibility of the
spring stem. Engineering of the tendon guides within such small channel dimensions of 3
mm was a challenge, which we overcame by designing our own customized set of tools and
drilling systems. The complete end-effector is comprising of the spring backbone,
instrument head, actuating tendons, and guides. By investigating different tendon routing
and anchoring mechanisms, this study shows the functionality of multichannel spring
backbone manipulations, with single-port centimeter-level diameter luminal constraints and
each single-channel with outer diameter of less than 23 mm.

7.1 Introduction

The current surgical method of treatment for giant cell tumor (GCT) is through intralesional
curettage procedure. In this procedure, a sizeable cortical window is first made with a high-
power burr to expose the tumor. A curette is then used to resect the tumor from the bone.
After the curettage process is completed, autograft reconstruction is carried out to fill the
bone cavity. In some cases, excision of surrounding bone tissue would be required to ensure
adequate tumor clearance for complete resection of the tumor. The current surgical
procedure requires significant removal of cortical bone, which would increase the risk of

Flexible Robotics in Medicine.
DOI: https://doi.org/10.1016/B978-0-12-817595-8.00007-9 169
© 2020 Elsevier Inc. All rights reserved.