DGIST Scholar: Flexible Surgical Robot with High Stiffness by Preventing Twist Deformation

Department of Robotics and Mechatronics Engineering Theses Ph.D.

Cited time in webofscience

Cited time in scopus

Flexible Surgical Robot with High Stiffness by Preventing Twist Deformation

Title: Flexible Surgical Robot with High Stiffness by Preventing Twist Deformation

Alternative Title: 비틀림 변형을 방지하여 높은 강성을 갖는 굴곡형 수술로봇 시스템 개발

Author(s): Daekeun Ji

DGIST Authors: Kang, Taehun ; Ji, Daekeun ; Hong, Jaesung

Advisor: 홍재성

Co-Advisor(s): Tae Hun Kang

Issued Date: 2020

Awarded Date: 2020-02

Type: Thesis

Description: Flexible manipulator, twist deformation, minimally invasive surgery, master device.

Table Of Contents: I. INTRODUCTION 1
1.1 Introduction to Minimally Invasive Surgery (MIS) 1
1.2 Need for Flexible Manipulator (FM) 2
1.3 Previous researches of flexible manipulator (FM) for MIS 4
1.4 Limitations of current FM for MIS 9
1.5 Twist deformation. 11
1.6 Previous researches of FM mechanism for preventing the twist deformation 13
1.7 Aims of proposed researches 15
II. ANALYSIS OF TWIST DEFORMATION IN WIRE-DRIVEN FM 17
2.1 Static analysis of twist torque 17
2.2 Models for twist deformation 22
2.1.1 Clearance effect model 24
2.1.2 Sag effect model 27
2.3 Experiment and results 30
2.3.1 Clearance effect test 30
2.3.2 Sag effect test 32
2.3.3 Payload test with an actual FM 37
2.4 Discussion 41
2.5 Conclusion 43
III. DESIGN OF WIRE-DRIVEN FM WITH CONSTRAINED SPHERICAL JOINTS FOR MIS 44
3.1 Limitations of existing FM 44
3.2 Design consideration for MIS 46
3.3 Ball constrained spherical (BCS) joint 47
3.4 Design considerations for BCS joint mechanism 51
3.4.1 Consideration of joint shape 51
3.4.2 Consieration of forceps 55
3.4.3 Spring 57
3.4.4 Forward kinematics of the flexible robot with BCS joint 60
3.5 Experiment and results 61
3.5.1 Curvature measurement 63
3.5.2 Twist deformation measurement with payload 66
3.5.3 Position accuracy test 68
3.5 Discussion 70
3.6 Conclusion 72
IV. DESIGN OF MASTER DEVICE FOR FM 73
4.1 Limitations of existing master device for FM 73
4.2 Design consideration of master device 74
4.3 Design of the isosceles master device 76
4.3.1 Variable isosceles triangle mechanism 77
4.3.2 Passive Holding Mechanism 79
4.3.3 Forward kinematics of the isosceles master device 81
4.3.4 Prototype of the isosceles master device 83
4.4 Experiment and results 85
4.4.1 Accuracy test with the flexible slave robot 85
4.4.2 Wire tension measurement 89
4.4.3 Holding test 91
4.5 Discussion 93
4.6 Conclusion 94
V. CONCLUSION AND FURTHER WORKS 95