Stapler Design with Stacked Tensegrity Mechanisms for Surgical Procedures

Dhruva Khanzode (1) , Ranjan Jha (1) , Damien Chablat (2, 3) , Emilie Duchalais (4)

1 CISR - National Institute for Interdisciplinary Science and Technology
2 LS2N - Laboratoire des Sciences du Numérique de Nantes
3 LS2N - équipe ReV - Robotique Et Vivant
4 CHU Nantes - Centre Hospitalier Universitaire de Nantes

In this paper, a planar mechanism formed by stacking tensegrity mechanisms has been designed. This mechanism is formed by three segments but the approach can be applied to a larger number of segments. This mechanism is studied to serve as a stapler for laparoscopic rectal cancer surgery where conventional tools cannot be easily accessed. To do this, two identical mechanisms will be used and operated similarly: one to carry the clips and the cutting knife and the second in parallel to allow the closing of the clips by bringing the two mechanisms together. The parameterization of the segments allows a variation of all lengths. Thus, the size of the segments can decrease proportionally from the base to the top, resulting in a tapered shape from the base to the tip like an elephant trunk. The mechanism has linear springs and cables for its actuation. The singularities, as well as the stability of the parallel mechanism, were analyzed using the minimum energy principle. Optimization was also performed to obtain the largest angular deflection for a segment based on a ratio between the size of the base and the moving platform of the robotic system. The result of this work is a family of mechanisms that can generate the same workspace for different stability properties. After optimization, the radius of curvature of the mechanism will be studied to allow insertion into the patient's belly.

Domaines: Robotique [cs.RO]

Dhruva Khanzode, Ranjan Jha, Damien Chablat, Emilie Duchalais. Stapler Design with Stacked Tensegrity Mechanisms for Surgical Procedures. Proceedings of the ASME 2022 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, Aug 2022, Saint Louis, United States. ⟨hal-03788641⟩