Flexible Over-the-Tube Device for Soft-Tethered Colonoscopy

Yu Huan, Xuyang Ren (Lead / Corresponding author), Andrea Firrincieli, Luigi Manfredi, Matteo Cianchetti, Alberto Arezzo, Edoardo Sinibaldi (Lead / Corresponding author), Gastone Ciuti (Lead / Corresponding author)

Research output: Contribution to journalArticlepeer-review

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Soft-tethered colonoscopes were proposed for safe and effective colon navigation, yet the deployment of front-wheel actuated colonoscopes is hindered by contact interactions with the lumen along the entire soft tether. To mitigate this problem, this study introduces an over-the-tube flexible device aimed to assist colonoscope deployment. The device is composed of three pneumatically driven actuators devised to repeatedly perform a two-phase operation: (phase I) to advance along the tether up to a working position relatively close to the colonoscope’s tip; (phase II) to clamp and drag the tether forward, upon anchoring to colonic wall. This way, a distal tether portion is freed, thus reducing the aforementioned limitations and fostering effective front-wheel navigation. Considering anatomical/clinical constraints and a 2N resistive force, we designed and prototyped a system with an inner and outer diameter of 12 and 26 mm, respectively, a length of 91 mm, and operating pressures equal to 150, 50 and 15 kPa for clamping the tether, elongating the device and safely anchoring to the colonic wall, respectively. The device was successfully tested, achieving locomotion speeds up to 4.9 and 2.2 mm/s, and tether freeing rates up to 2.9 and 1.8 mm/s, in tabletop conditions and in a colon phantom, respectively.
Original languageEnglish
Pages (from-to)1-11
Number of pages11
JournalIEEE/ASME Transactions on Mechatronics
Publication statusPublished - 19 Oct 2023


  • mechatronic system
  • over-the-tube device
  • pneumatic actuation
  • robotic endoscopy
  • soft-tethered colonoscopy
  • Force
  • Colonoscopy
  • Colon
  • Navigation
  • Electromagnetic compatibility
  • Actuators
  • Radio frequency
  • Mechatronic system

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Control and Systems Engineering
  • Computer Science Applications


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