Compliant joints composed of slit tubes or springs are commonly utilized for steerable endoscopes and catheters. Because this type of joint is actuated by means of its elasticity, it is difficult to bend it with a small radius of curvature. In order to overcome this problem, a hyper-redundant Pulleyless Rolling joint with Elastic Fixtures (PREF joint) is proposed. To enable miniaturization, the PREF joint does not have a pulley, and the rolling contact motion aids the actuation cables to maintain the tension. The elastic fixtures guarantee a stable rolling motion at the center of the rolling surfaces. In this paper, the fundamental characteristics for the unit and the hyper-redundant PREF joints are presented. Moreover, design considerations are proposed for the PREF joint including the rolling tooth shape, structure of the elastic fixtures, and cable actuation method. The validity of the design is verified using finite-element analysis and a 10 mm diameter prototype composed of 12 units of PREF joints for a 1 degree-of-freedom motion. As a result, the 55 mm long joint can be bent up to 짹180째 with low actuation tension. The presented guidelines will assist in the development of various steerable instruments for medical applications.
KSP Keywords
Compliant joints, Degrees of freedom(DOF), Design considerations, Fundamental characteristics, Low actuation, Medical Applications, Radius of curvature, Rolling contact, Rolling surfaces, Tooth shape, finite element analysis(FEA)
Copyright Policy
ETRI KSP Copyright Policy
The materials provided on this website are subject to copyrights owned by ETRI and protected by the Copyright Act. Any reproduction, modification, or distribution, in whole or in part, requires the prior explicit approval of ETRI. However, under Article 24.2 of the Copyright Act, the materials may be freely used provided the user complies with the following terms:
The materials to be used must have attached a Korea Open Government License (KOGL) Type 4 symbol, which is similar to CC-BY-NC-ND (Creative Commons Attribution Non-Commercial No Derivatives License). Users are free to use the materials only for non-commercial purposes, provided that original works are properly cited and that no alterations, modifications, or changes to such works is made. This website may contain materials for which ETRI does not hold full copyright or for which ETRI shares copyright in conjunction with other third parties. Without explicit permission, any use of such materials without KOGL indication is strictly prohibited and will constitute an infringement of the copyright of ETRI or of the relevant copyright holders.
J. Kim et. al, "Trends in Lightweight Kernel for Many core Based High-Performance Computing", Electronics and Telecommunications Trends. Vol. 32, No. 4, 2017, KOGL Type 4: Source Indication + Commercial Use Prohibition + Change Prohibition
J. Sim et.al, “the Fourth Industrial Revolution and ICT – IDX Strategy for leading the Fourth Industrial Revolution”, ETRI Insight, 2017, KOGL Type 4: Source Indication + Commercial Use Prohibition + Change Prohibition
If you have any questions or concerns about these terms of use, or if you would like to request permission to use any material on this website, please feel free to contact us
KOGL Type 4:(Source Indication + Commercial Use Prohibition+Change Prohibition)
Contact ETRI, Research Information Service Section
Privacy Policy
ETRI KSP Privacy Policy
ETRI does not collect personal information from external users who access our Knowledge Sharing Platform (KSP). Unathorized automated collection of researcher information from our platform without ETRI's consent is strictly prohibited.
[Researcher Information Disclosure] ETRI publicly shares specific researcher information related to research outcomes, including the researcher's name, department, work email, and work phone number.
※ ETRI does not share employee photographs with external users without the explicit consent of the researcher. If a researcher provides consent, their photograph may be displayed on the KSP.