title: A modular force-controlled robotic instrument for minimally invasive surgery - efficacy for being used in autonomous grasping against a variable pull force.
abstract: BACKGROUND
  Many deficiencies of minimally invasive robotic surgery systems can be eliminated by using automated laparoscopic tools with force measurement and control capability.
  
  
  METHODS
  A fully modular, automated laparoscopic instrument with a proximal force sensory system was designed and fabricated. The efficacy of the instrument was evaluated experimentally when functioning in an autonomous force-controlled grasping scheme.
  
  
  RESULTS
  The designed instrument was shown to work easily with standard laparoscopic tools, with the whole distal part detachable for autoclave sterilization. The root mean squared error (RMSE) of the actual pinch force from the target ramp was 0.318 N; it was 0.402 N for a sinusoidal pull force, which dropped by 21% using a static friction compensation. A secure grasping condition was achieved, in spite of this error, by applying a sufficiently large margin from the slip boundary.
  
  
  CONCLUSIONS
  With a simple and practical design, the instrument enjoys affordability, versatility and autoclave sterilizability for clinical usage, with an acceptable performance for being used in an auto-grasping control scheme. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Mechanical Engineering Department, Sharif University of Technology, Tehran, Iran.|Research Centre for Biomedical Technologies and Robotics (RCBTR), Tehran University of Medical Sciences, Iran.
authors.forename: Seyed Mohsen
authors.initials: SM
authors.lastname: Khadem
authors.affiliation: Mechanical Engineering Department, Sharif University of Technology, Tehran, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Behzadipour
authors.affiliation: Medical Physics and Biomedical Engineering Department, School of Medicine and Research Centre for Biomedical Technologies and Robotics (RCBTR), Tehran University of Medical Sciences, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Mirbagheri
authors.affiliation: Mechanical Engineering Department, Sharif University of Technology, Tehran, Iran.|Research Centre for Biomedical Technologies and Robotics (RCBTR), Tehran University of Medical Sciences, Iran.
authors.forename: Farzam
authors.initials: F
authors.lastname: Farahmand
mesh_terms: D000465:Algorithms; D000818:Animals; D001331:Automation; D002138:Calibration; D004867:Equipment Design; D018737:Hand Strength; D006801:Humans; D020706:Laparoscopes; D010535:Laparoscopy / Q000379:methods*; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D015203:Reproducibility of Results; D065287:Robotic Surgical Procedures / Q000379:methods*; D013314:Stress, Mechanical
keywords: auto-grasp; force control; laparoscopic instrument; minimally invasive surgery; robotic surgery