Kinematics of a robotic 3UPS1S spherical wrist designed for laparoscopic applications
Jose Sabater Navarro, Nicolas Garcia, Carlos Perez-Vidal, Eduardo Fernandez, Roque Saltaren, Miguel Almonacid
 ISSN:1478-5951  DOI:  - Vol. 6 (3) pp. 291-300


Background Current robotic orientation surgical devices used to be large, in order to cover the needed workspace and to be rigid enough to resist the forces that occur during surgery. The disadvantages of the large size of the devices are the ergonomics, collisions and interference with the surgeons. This paper presents the first steps that have been carried out on the development of a small spherical wrist for laparoscopic applications.
Methods Screw theory for kinematic analysis and the design of parallel robots have been used for choosing the kinematic architecture of the first prototype of the laparoscopic wrist. The kinematic equations of the platform are described and the Jacobian matrix calculated.
Results The kinematics of this device is a 3UPS-1S parallel architecture. The work presented here shows the concept of the device, its design, that it was made under intrinsic safety criteria, its kinematic analysis and the first results and images of the built prototype. The kinematic analysis is made using screw theory and it is used to verify the optimization of the design.
Conclusions A new design for a smart and small spherical wrist is developed. Ergonomics for the surgical team is a design criterion that should be introduced to the design process for an operating-room robotic tool. Parallel robots architecture can contribute to new devices that fit this criterion.