title: Effects of visual force feedback on robot-assisted surgical task performance.
abstract: OBJECTIVE
  Direct haptic (force or tactile) feedback is negligible in current surgical robotic systems. The relevance of haptic feedback in robot-assisted performances of surgical tasks is controversial. We studied the effects of visual force feedback, a haptic feedback surrogate, on tying surgical knots with fine sutures similar to those used in cardiovascular surgery.
  
  
  METHODS
  By using a modified da Vinci robotic system (Intuitive Surgical, Inc, Sunnyvale, Calif) equipped with force-sensing instrument tips and real-time visual force feedback overlays in the console image, 10 surgeons each tied 10 knots with and 10 knots without visual force feedback. Four surgeons had significant prior da Vinci experience, and the remaining 6 surgeons did not. Performance parameters, including suture breakage and secure knots, peak and standard deviation of applied forces, and completion times using 5-0 silk sutures, were recorded. Chi-square and Student t test analyses determined the differences between groups.
  
  
  RESULTS
  Among surgeon subjects with robotic experience, no differences in measured performance parameters were found between robot-assisted knot ties executed with and without visual force feedback. Among surgeons without robotic experience, however, visual force feedback was associated with lower suture breakage rates, peak applied forces, and standard deviations of applied forces. Visual force feedback did not impart differences in knot completion times or loose knots for either surgeon group.
  
  
  CONCLUSIONS
  Visual force feedback resulted in reduced suture breakage, lower forces, and decreased force inconsistencies among novice robotic surgeons, although elapsed time and knot quality were unaffected. In contrast, visual force feedback did not affect these metrics among surgeons experienced with the da Vinci system. These results suggest that visual force feedback primarily benefits novice robot-assisted surgeons, with diminishing benefits among experienced surgeons.
authors.affiliation: Engineering Research Center and Computer Integrated Surgery Systems and Technology, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Carol E
authors.initials: CE
authors.lastname: Reiley
authors.forename: Takintope
authors.initials: T
authors.lastname: Akinbiyi
authors.forename: Darius
authors.initials: D
authors.lastname: Burschka
authors.forename: David C
authors.initials: DC
authors.lastname: Chang
authors.forename: Allison M
authors.initials: AM
authors.lastname: Okamura
authors.forename: David D
authors.initials: DD
authors.lastname: Yuh
mesh_terms: D005246:Feedback; D006801:Humans; D019563:Mechanics; D009048:Motor Skills; D012371:Robotics; D012677:Sensation; D025321:Surgery, Computer-Assisted; D013536:Suture Techniques; D013647:Task Performance and Analysis