title: [Endolaryngeal distance measurement by laser light projection--from the idea to clinical application].
abstract: BACKGROUND
  In clinical and scientific examinations with rigid and flexible endoscopes quantitative morphometric measurements of intralaryngeal structures have been difficult whereas qualitative laryngoscopic examinations are routine procedures.
  
  
  METHODS
  The development of a two-point light projection method for endolaryngeal morphometry in its different phases is described. The way from a first prototype for endolaryngeal morphometry that works with a prism technique to the latest, most modern prototype, which works with a double reflecting mirror is shown.
  
  
  RESULTS
  In combination with a newly developed PC software the latest prototype for two-point laser-light projection enables an accuracy of 95 % to 99 % in the measurement of intralaryngeal distances. The contrast of the laser beams to the mucous membrane of the larynx could be optimized by the use of green--instead of red--laser light.
  
  
  CONCLUSIONS
  Morphological measurements within the larynx are now possible for clinical and scientific questions. Former limitations in quantitative morphometric examinations will be reduced.
authors.affiliation: Poliklinik für Hör-, Stimm- und Sprachheilkunde, Universitätsklinikum Hamburg-Eppendorf. g.schade@uke.uni-hamburg.de
authors.forename: G
authors.initials: G
authors.lastname: Schade
authors.forename: B
authors.initials: B
authors.lastname: Rassow
authors.forename: Th
authors.initials: T
authors.lastname: Kirchhoff
authors.forename: M
authors.initials: M
authors.lastname: Kraas
authors.forename: M
authors.initials: M
authors.lastname: Hess
mesh_terms: D004867:Equipment Design; D006801:Humans; D020704:Laryngoscopes; D007830:Larynx / Q000033:anatomy & histology*; D007834:Lasers; D010036:Otolaryngology / Q000295:instrumentation*; D012984:Software; D014827:Vocal Cords / Q000033:anatomy & histology