title: Integrated Multipoint-Laser Endoscopic Airway Measurements by Transoral Approach.
abstract: OBJECTIVE
  Optical and technical characteristics usually do not allow objective endoscopic distance measurements. So far no standardized method for endoscopic distance measurement is available. The aim of this study was to evaluate the feasibility and accuracy of transoral airway measurements with a multipoint-laser endoscope.
  
  
  METHODS
  The semirigid endoscope includes a multipoint laser measurement system that projects 49 laser points (wavelength 639 nm, power < 5 mW) into the optical axis of the endoscopic view. Distances, areas, and depths can be measured in real-time. Transoral endoscopic airway measurements were performed on nine human cadavers, which were correlated with CT measurements.
  
  
  RESULTS
  The preliminary experiment showed an optimum distance between the endoscope tip and the object of 5 to 6 cm. There was a mean measurement error of 3.26% ± 2.53%. A Spearman correlation coefficient of 0.95 (p = 0.01) was calculated for the laryngeal measurements and of 0.93 (p < 0.01) for the tracheal measurements compared to the CT. Using the Bland-Altman-Plot, the 95% limits of agreement for the laryngeal measurements were satisfactory: -0.76 and 0.93.
  
  
  CONCLUSIONS
  Integrated multipoint-laser endoscopic measurement is a promising technical supplement, with potential use in diagnostic endoscopy and transoral endoscopic surgery in daily practice.
authors.affiliation: Clinic of Otolaryngology, Head and Neck Surgery, Department of Head Medicine and Oral Health, University Hospital Leipzig, Liebigstrasse 12, 04103 Leipzig, Germany.
authors.forename: Marie
authors.initials: M
authors.lastname: Neitsch
authors.affiliation: Clinic of Otolaryngology, Head and Neck Surgery, Department of Head Medicine and Oral Health, University Hospital Leipzig, Liebigstrasse 12, 04103 Leipzig, Germany.
authors.forename: Iris-Susanne
authors.initials: IS
authors.lastname: Horn
authors.affiliation: Clinic of Otolaryngology, Head and Neck Surgery, Department of Head Medicine and Oral Health, University Hospital Leipzig, Liebigstrasse 12, 04103 Leipzig, Germany.
authors.forename: Mathias
authors.initials: M
authors.lastname: Hofer
authors.affiliation: Clinic of Otolaryngology, Head and Neck Surgery, Department of Head Medicine and Oral Health, University Hospital Leipzig, Liebigstrasse 12, 04103 Leipzig, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Dietz
authors.affiliation: Clinic of Otolaryngology, Head and Neck Surgery, Department of Head Medicine and Oral Health, University Hospital Leipzig, Liebigstrasse 12, 04103 Leipzig, Germany.
authors.forename: Miloš
authors.initials: M
authors.lastname: Fischer
mesh_terms: D019723:Endoscopes; D005260:Female; D006801:Humans; D007828:Laryngoscopy / Q000295:instrumentation / Q000379:methods; D007830:Larynx / Q000000981:diagnostic imaging*; D007834:Lasers; D008297:Male; D008962:Models, Theoretical