title: Forces and displacements in colon surgery.
abstract: BACKGROUND
  This study aims to find criteria for designing safer laparoscopic graspers for manipulation of delicate tissues. Since the experiment was performed in an open-surgery setup without any movement restrictions, the results are relevant to general surgery as well as laparoscopic.
  
  
  METHODS
  Four surgeons were asked to apply via two clamps enough force to a pig's colon to stretch the mesocolon for dissection. Directions, magnitudes, and application points of the forces were recorded.
  
  
  RESULTS
  The surgeons applied per clamp on average 2.5 N and maximally 5 N to the colon. These forces were at an angle of about 40 degrees to 70 degrees relative to the horizontal plane and approximately 60 degrees relative to each other.
  
  
  CONCLUSIONS
  Safe laparoscopic graspers should be able to transmit at least a 5 N pull force to the tissue without damaging it. To minimize the forces used, the angles mentioned should be taken into account when placing the trocars.
authors.affiliation: Minimally Invasive Surgery and Interventional Techniques, Delft University of Technology, Mekelweg 2, 2628CD Delft, The Netherlands. h.devisser@wbmt.tudelft.nl
authors.forename: H
authors.initials: H
authors.lastname: de Visser
authors.forename: E A M
authors.initials: EA
authors.lastname: Heijnsdijk
authors.forename: J L
authors.initials: JL
authors.lastname: Herder
authors.forename: P V
authors.initials: PV
authors.lastname: Pistecky
mesh_terms: D000818:Animals; D003106:Colon / Q000601:surgery*; D004867:Equipment Design / Q000379:methods; D004869:Equipment Safety / Q000379:methods; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control; D007699:Kinesthesis; D020706:Laparoscopes; D010535:Laparoscopy / Q000379:methods*; D008328:Man-Machine Systems; D008646:Mesocolon / Q000601:surgery; D013552:Swine