title: Visual force feedback in laparoscopic training.
abstract: BACKGROUND
  To improve endoscopic surgical skills, an increasing number of surgical residents practice on box or virtual reality (VR) trainers. Current training is focused mainly on hand-eye coordination. Training methods that focus on applying the right amount of force are not yet available.
  
  
  METHODS
  The aim of this project is to develop a low-cost training system that measures the interaction force between tissue and instruments and displays a visual representation of the applied forces inside the camera image. This visual representation continuously informs the subject about the magnitude and the direction of applied forces. To show the potential of the developed training system, a pilot study was conducted in which six novices performed a needle-driving task in a box trainer with visual feedback of the force, and six novices performed the same task without visual feedback of the force. All subjects performed the training task five times and were subsequently tested in a post-test without visual feedback.
  
  
  RESULTS
  The subjects who received visual feedback during training exerted on average 1.3 N (STD 0.6 N) to drive the needle through the tissue during the post-test. This value was considerably higher for the group that received no feedback (2.6 N, STD 0.9 N). The maximum interaction force during the post-test was noticeably lower for the feedback group (4.1 N, STD 1.1 N) compared with that of the control group (8.0 N, STD 3.3 N).
  
  
  CONCLUSIONS
  The force-sensing training system provides us with the unique possibility to objectively assess tissue-handling skills in a laboratory setting. The real-time visualization of applied forces during training may facilitate acquisition of tissue-handling skills in complex laparoscopic tasks and could stimulate proficiency gain curves of trainees. However, larger randomized trials that also include other tasks are necessary to determine whether training with visual feedback about forces reduces the interaction force during laparoscopic surgery.
authors.affiliation: Department of BioMechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering (3mE), Delft University of Technology, Mekelweg 2, 2628 CD, Delft, The Netherlands. T.Horeman@tudelft.nl
authors.forename: Tim
authors.initials: T
authors.lastname: Horeman
authors.forename: Sharon P
authors.initials: SP
authors.lastname: Rodrigues
authors.forename: John J
authors.initials: JJ
authors.lastname: van den Dobbelsteen
authors.forename: Frank-Willem
authors.initials: FW
authors.lastname: Jansen
authors.forename: Jenny
authors.initials: J
authors.lastname: Dankelman
mesh_terms: D002983:Clinical Competence / Q000592:standards*; D004501:Education, Medical / Q000379:methods*; D004867:Equipment Design; D005246:Feedback; D006801:Humans; D007396:Internship and Residency / Q000379:methods*; D020706:Laparoscopes; D010535:Laparoscopy / Q000193:education* / Q000295:instrumentation; D053580:Muscle Strength / Q000502:physiology; D010865:Pilot Projects; D012984:Software; D013663:Teaching / Q000379:methods*; D013997:Time Factors; D014741:Video Recording