title: Kinematics of a robotic 3UPS1S spherical wrist designed for laparoscopic applications.
abstract: 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.
authors.affiliation: Biomedical Neuroengineering Group, Miguel Hernandez University, Elche, Spain. j.sabater@umh.es
authors.forename: Jose Sabater
authors.initials: JS
authors.lastname: Navarro
authors.forename: Nicolas
authors.initials: N
authors.lastname: Garcia
authors.forename: Carlos
authors.initials: C
authors.lastname: Perez
authors.forename: Eduardo
authors.initials: E
authors.lastname: Fernandez
authors.forename: Roque
authors.initials: R
authors.lastname: Saltaren
authors.forename: Miguel
authors.initials: M
authors.lastname: Almonacid
mesh_terms: D000005:Abdomen / Q000601:surgery; D001696:Biomechanical Phenomena / Q000502:physiology; D004867:Equipment Design; D006804:Ergonomics / Q000295:instrumentation / Q000379:methods; D006801:Humans; D010535:Laparoscopy / Q000295:instrumentation* / Q000379:methods*; D008962:Models, Theoretical; D012371:Robotics / Q000295:instrumentation* / Q000379:methods*; D013525:Surgical Instruments / Q000592:standards; D017132:Workplace / Q000706:statistics & numerical data; D014953:Wrist / Q000033:anatomy & histology*