Page 396 - Flexible Robotics in Medicine

CHAPTER 17

Single-port multichannel multi-degree-of-

freedom robot with variable stiffness

for natural orifice transluminal endoscopic

surgery

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1
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1
Changsheng Li , Xiao Xiao , Xiaoyi Gu 1,2 , Feng Jie , Shanmugam Sangeetha ,
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Toon Zhu Wei Joelle , Trevor Tan Wei Kiat and Hongliang Ren 1,2
1 2
Department of Biomedical Engineering, National University of Singapore, Singapore, NUS (Suzhou)
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Research Institute (NUSRI), Suzhou, P.R. China, Department of Mechanical Engineering, National
University of Singapore, Singapore
Natural orifice transluminal endoscopic surgery (NOTES) emerges with advantages of less
scar, less pain or bleeding, and better anesthesia, in comparison with open or laparoscopic
surgery. Current surgical instruments for NOTES lack stiffness tuning capability and
require high-level surgical skills, as the natural orifice is long and narrow. The conventional
robots with constant stiffness are not ideal for NOTES, because variable stiffness of the
manipulator is desirable for satisfactory dexterous operation and navigating through
transluminal trajectories. Flexibility is essential for safe curvilinear access, while rigidity is
essential for dexterity. As a result, we are addressing the stiffness modulation needs by
developing a robotic endoscopy system with variable stiffness and flexible manipulators for
NOTES. A single-port multichannel multi-degree-of-freedom robot with variable stiffness
in this work is composed of a camera and two manipulators based on the endoscopic
platform. The manipulators are compliant with variable stiffness, and the wrist joints are
flexible. The stiffness of the compliant manipulator tunes in real-time during the operation
to fulfill the accuracy and safety requirements of the surgery environment. The mechanism
and experiments validate the variation of the stiffness. Results show that the stiffness of the
manipulator is variable, which can be tuned by the tension of the wires.

17.1 Introduction

The laparoscopic surgery involves the insertion of multiple surgical instruments and a
camera at different sides of the abdomen of a patient via various inserts. This procedure

Flexible Robotics in Medicine.
DOI: https://doi.org/10.1016/B978-0-12-817595-8.00018-3 389
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