Open AccessA Submillimeter Continuous Variable Stiffness Catheter for Compliance Control
Author(s) -
Lussi Jonas,
Mattmann Michael,
Sevim Semih,
Grigis Fabian,
De Marco Carmela,
Chautems Christophe,
Pané Salvador,
PuigmartíLuis Josep,
Boehler Quentin,
Nelson Bradley J.
Publication year - 2021
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202101290
Subject(s) - stiffness , catheter , computer science , imaging phantom , smoothness , phase (matter) , variable (mathematics) , control theory (sociology) , biomedical engineering , mechanical engineering , materials science , surgery , physics , control (management) , artificial intelligence , medicine , engineering , optics , mathematics , composite material , mathematical analysis , quantum mechanics
Minimally invasive robotic surgery often requires functional tools that can change their compliance to adapt to the environment and surgical needs. This paper proposes a submillimeter continuous variable stiffness catheter equipped with a phase‐change alloy that has a high stiffness variation in its different states, allowing for rapid compliance control. Variable stiffness is achieved through a variable phase boundary in the alloy due to a controlled radial temperature gradient. This catheter can be safely navigated in its soft state and rigidified to the required stiffness during operation to apply a desired force at the tip. The maximal contact force that the catheter applies to tissue can be continuously modified by a factor of 400 (≈20 mN–8 N). The catheter is equipped with a magnet and a micro‐gripper to perform a fully robotic ophthalmic minimally invasive surgery on an eye phantom by means of an electromagnetic navigation system.