This work presents a novel miniature contact-aided compliant joint mechanism that can be integrated into millimeter-sized manual or robotic surgical instruments. The design aims to address the trade-off between notched-tube compliant joints' range of motion and stiffness, while also ensuring a compact form factor. The mechanism is constructed from a nitinol tube with asymmetric cutouts and is actuated in bending by a cable. The innovative feature of this design is the incorporation of a contact aid into the notched-tube topology, which acts to both increase the stiffness of the joint and change the shape that it undertakes during bending. Using finite element modeling (FEM) techniques, we present a sensitivity analysis investigating how the performance of this contact-aided compliant mechanism (CCM) is affected by its geometry, and derive a kinematics and statics model for the joint. The FEM simulations and the kinematic and static models are compared to experimental results. The design and modeling presented in this study can be used to develop new miniature dexterous instruments, with a particular emphasis on applications in minimally invasive neurosurgery.
Design of a Contact-Aided Compliant Notched-Tube Joint for Surgical Manipulation in Confined Workspaces
Center for Image Guided Innovation and
Therapeutic Intervention (CIGITI),
The Hospital for Sick Children,
555 University Avenue,
Toronto, ON M5G 1X8, Canada
Manuscript received May 18, 2017; final manuscript received September 27, 2017; published online December 20, 2017. Assoc. Editor: Robert J. Wood.
Eastwood, K. W., Francis, P., Azimian, H., Swarup, A., Looi, T., Drake, J. M., and Naguib, H. E. (December 20, 2017). "Design of a Contact-Aided Compliant Notched-Tube Joint for Surgical Manipulation in Confined Workspaces." ASME. J. Mechanisms Robotics. February 2018; 10(1): 015001. https://doi.org/10.1115/1.4038254
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