title: Development of a compact continuum tubular robotic system for nasopharyngeal biopsy.
abstract: Traditional posterior nasopharyngeal biopsy using a flexible nasal endoscope has the risks of abrasion and injury to the nasal mucosa and thus causing trauma to the patient. Recently, a new class of robots known as continuum tubular robots (CTRs) provide a novel solution to the challenge with miniaturized size, curvilinear maneuverability, and capability of avoiding collision within the nasal environment. This paper presents a compact CTR which is 35 cm in total length, 10 cm in diameter, 2.15 kg in weight, and easy to be integrated with a robotic arm to perform more complicated operations. Structural design, end-effector design, and workspace analysis are described in detail. In addition, teleoperation of the CTR using a haptic input device is developed for position control in 3D space. Moreover, by integrating the robot with three electromagnetic tracking sensors, a navigation system together with a shape reconstruction algorithm is developed. Comprehensive experiments are conducted to test the functionality of the proposed prototype; experiment results show that under teleoperation, the system has an accuracy of 2.20 mm in following a linear path, an accuracy of 2.01 mm in following a circular path, and a latency time of 0.1 s. It is also found that the proposed shape reconstruction algorithm has a mean error of around 1 mm along the length of the tubes. Besides, the feasibility and effectiveness of the proposed robotic system being applied to posterior nasopharyngeal biopsy are demonstrated by a cadaver experiment. The proposed robotic system holds promise to enhance clinical operation in transnasal procedures.
authors.affiliation: School of Electrical Engineering and Computer Science, Queensland University of Technology, Brisbane, Australia.
authors.forename: Liao
authors.identifier: http://orcid.org/0000-0002-4554-7638
authors.initials: L
authors.lastname: Wu
authors.affiliation: School of Mechanical Engineering and Automation, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Song
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.
authors.forename: Keyu
authors.initials: K
authors.lastname: Wu
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, National University Hospital, Singapore, Singapore.
authors.forename: Chwee Ming
authors.initials: CM
authors.lastname: Lim
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore. ren@nus.edu.sg.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Ren
mesh_terms: D001696:Biomechanical Phenomena; D001706:Biopsy; D002102:Cadaver; D006801:Humans; D009305:Nasopharynx / Q000473:pathology*; D066330:Printing, Three-Dimensional; D012371:Robotics / Q000295:instrumentation* / Q000379:methods*; D013686:Telemetry
keywords: Concentric tube robots; Continuum tubular robots; Minimally invasive surgery; Nasopharyngeal biopsy; Transnasal surgical robot