Integrated Multipoint-Laser Endoscopic Airway Measurements by Transoral Approach

Abstract

Objectives. 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.

A Simple Endoscopic Technique for Measuring the Cross-Sectional Area of the Upper Airway in a Rabbit Model

“…Over the past several years, other investigators have developed endoscopic measurement techniques for the airway. [4][5][6][7][8][9] These methods have mostly used specialized/modified instruments or software that are not commonly used in direct laryngoscopy and bronchoscopy. While each method has merits, we believe that the flexibility and simplicity of our technique will allow for any interested investigator or physician to utilize our method.…”

“…3 Numerous studies have looked at developing other techniques for assessing the size of the airway, but most of these methods-while accuratehave required the use of equipment that is not normally a part of a clinical direct laryngoscopy and bronchoscopy. [4][5][6][7][8][9][10][11] With commonly used endoscopic instruments and opensource image analysis software, we hypothesize that measuring an area of interest endoscopically can be easily and accurately performed among different surgeons independently in the pediatric airway. The objective of this paper is to demonstrate the accuracy and reliability of a simple endoscopic technique for measuring the CSA of the proximal airway.…”

“…3 Numerous studies have looked at developing other techniques for assessing the size of the airway, but most of these methods—while accurate—have required the use of equipment that is not normally a part of a clinical direct laryngoscopy and bronchoscopy. 4-11…”

The larynx ruler to measure height and profile of vocal folds: a proof of concept

“…Furthermore, it also requires postre-cording analysis, so it does not yield real-time readings. Compared to prior articles using the same technology, apart from application using a flexible endoscope, this is the first experimentation with a continuous line and it enables a fine analysis of the VF with the generated profile 11,12,13,14…”

“…If the region of interest is not flat, it could lead to relatively important errors. Neitsch et al have proposed a smart solution based on a matrix of points (instead of two points) 14. The main limitation here is that measurements are possible only where points are projected (or detectable).…”