title: A novel design for steerable instruments based on laser-cut nitinol.
abstract: OBJECTIVE
  Omnidirectional articulated instruments enhance dexterity. In neurosurgery, for example, the simultaneous use of 2 instruments through the same endoscopic shaft remains a difficult feat. It is, however, very challenging to manufacture steerable instruments of the requisite small diameter. We present a new technique to produce such instruments by means of laser cutting. Only 3 coaxial tubes are used. The middle tube has a cutting pattern that allows the steering forces to be transmitted from the proximal to the distal end. In this way the steering part is concealed in the wall of the tube. Large diameter articulated instruments such as for laparoscopy might benefit from the excellent tip stability provided by the same economical technology.
  
  
  METHODS
  Coaxial nitinol tubes are laser-cut with a Rofin Stent Cutter in a specific pattern. The 3 tubes are assembled by sliding them over one another, forming a single composite tube. In a surgical simulator, the neurosurgical microinstruments and laparoscopic needle drivers were evaluated on surgical convenience.
  
  
  RESULTS
  Simultaneous use of 2 neurosurgical instruments (1.5 mm diameter) through the same endoscopic shaft proved to be very intuitive. The tip of the steerable laparoscopic instruments (10 mm diameter) could resist a lateral force of more than 20 N. The angle of motion for either instrument was at least 70° in any direction.
  
  
  CONCLUSIONS
  A new design for steerable endoscopic instruments is presented. It allows the construction in a range from microinstruments to 10-mm laparoscopic devices with excellent tip stability.
authors: Ghent University Hospital, Ghent, Belgium frank.dewaele@ugent.be.
authors: Frank
authors: F
authors: Dewaele
authors: University Medical Centre Groningen, Groningen, Netherlands.
authors: Alain F
authors: AF
authors: Kalmar
authors: Ghent University, Ghent, Belgium.
authors: Frederic
authors: F
authors: De Ryck
authors: Ghent University, Ghent, Belgium.
authors: Nicolaas
authors: N
authors: Lumen
authors: Wotton Lawn Hospital, Gloucestershire, UK.
authors: Leonie
authors: L
authors: Williams
authors: Ghent University Hospital, Ghent, Belgium.
authors: Edward
authors: E
authors: Baert
authors: University Medical Centre Groningen, Groningen, Netherlands.
authors: Hugo
authors: H
authors: Vereecke
authors: Ghent University Hospital, Ghent, Belgium.
authors: Jean Pierre
authors: JP
authors: Kalala Okito
authors: Ghent University, Ghent, Belgium.
authors: Cyriel
authors: C
authors: Mabilde
authors: Ghent University, Ghent, Belgium.
authors: Bart
authors: B
authors: Blanckaert
authors: Ghent University, Ghent, Belgium.
authors: Vincent
authors: V
authors: Keereman
authors: Ghent University, Ghent, Belgium.
authors: Luc
authors: L
authors: Leybaert
authors: Ghent University, Ghent, Belgium.
authors: Yves
authors: Y
authors: Van Nieuwenhove
authors: Ghent University Hospital, Ghent, Belgium.
authors: Jacques
authors: J
authors: Caemaert
authors: Ghent University Hospital, Ghent, Belgium.
authors: Dirk
authors: D
authors: Van Roost
mesh_terms: D000497:Alloys / Q000737:chemistry* / Q000627:therapeutic use*; D017076:Computer-Aided Design; D004867:Equipment Design; D006801:Humans; D010535:Laparoscopy / Q000295:instrumentation*; D007834:Lasers; D008866:Microsurgery / Q000295:instrumentation*
chemical_list: D000497:Alloys; C013616:nitinol
keywords: endoscopy; laparoscopy; laser; microinstruments; nitinol; single port surgery; steerable