title: Tendon-Driven Continuum Robot for Endoscopic Surgery: Preclinical Development and Validation of a Tension Propagation Model.
abstract: In this paper, we present a tendon-driven continuum robot for endoscopic surgery. The robot has two sections for articulation actuated by tendon wires. By actuating the two sections independently, the robot can generate a variety of tip positions while maintaining the tip direction. This feature offers more flexibility in positioning the tip for large viewing angles of up to 180 degrees than does a conventional endoscope. To accurately estimate the tip position at large viewing angles, we employed kinematic mapping with a tension propagation model including friction between the tendon wires and the robot body. In a simulation study using this kinematic-mapping, the two-section robot at a target scale (outer diameter 1.7 mm and length 60 mm) produced a variety of tip positions within 50-mm ranges at the 180°-angle view. In the experimental validation, a 10:1 scale prototype performed three salient postures with different tip positions at the 180°-angle view. The proposed forward kinematic mapping (FKM) predicted the tip position within a tip-to-tip error of 6 mm over the 208-mm articulating length. The tip-to-tip error by FKM was significantly less than the one by conventional piecewise-constant-curvature approximation (PCCA) (FKM: 5.9 ± 2.9 mm vs. PCCA: 23.7 ± 3.6 mm, n=15, P < 0.01).
authors.affiliation: National Center for Image Guided Therapy, Brigham and Women's Hospital and Harvard Medical School, MA, USA ( kato@bwh.harvard.edu ); Healthcare Optics Research Laboratory, Canon U.S.A., Inc., MA, USA ( takato@cusa.canon.com ).
authors.forename: Takahisa
authors.initials: T
authors.lastname: Kato
authors.affiliation: Advanced Systems R&D Center, Canon Inc., Japan. ( okumura.ichiro@canon.co.jp ).
authors.forename: Ichiro
authors.initials: I
authors.lastname: Okumura
authors.affiliation: National Center for Image Guided Therapy, Brigham and Women's Hospital and Harvard Medical School, MA, USA ( sam@bwh.harvard.edu ).
authors.forename: Sang-Eun
authors.initials: SE
authors.lastname: Song
authors.affiliation: Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, MA USA ( agolby@partners.org ).
authors.forename: Alexandra J
authors.initials: AJ
authors.lastname: Golby
authors.affiliation: National Center for Image Guided Therapy, Brigham and Women's Hospital and Harvard Medical School, MA, USA ( nhata@partners.org ).
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Hata
keywords: Dexterous manipulators; Medical robotics; Robot kinematics; Surgery