Development of a compact continuum tubular robotic system for nasopharyngeal biopsy

Med Biol Eng Comput. 2017 Mar;55(3):403-417. doi: 10.1007/s11517-016-1514-9. Epub 2016 May 18.

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.

Keywords: Concentric tube robots; Continuum tubular robots; Minimally invasive surgery; Nasopharyngeal biopsy; Transnasal surgical robot.

MeSH terms

  • Biomechanical Phenomena
  • Biopsy
  • Cadaver
  • Humans
  • Nasopharynx / pathology*
  • Printing, Three-Dimensional
  • Robotics / instrumentation*
  • Robotics / methods*
  • Telemetry