Noncontact Three-Dimensional Laser Measuring Device for Tracheoscopy

Abstract

Luminal dimension measurements are still an unsolved problem in endoscopy. The goal of our study was to develop a 3-dimensional (3-D) measuring device for endoscopic applications. For this purpose, a fiber probe projecting a ring of laser light (laser diode, 675 nm) was integrated in a position registration system. Software was developed for image analysis, distortion correction, and export of data for 3-D display. Experimental evaluation of measuring accuracy employing plastic tubes and 15 postmortem pig trachea preparations with artificial stenosis indicated a high level of method precision (Pearson's correlation coefficients, r = 0.99 for normal tracheal lumen and r = 0.97 for high-grade stenosis; p < .0001). Our clinical experience with the technique in 10 patients with tracheal stenosis revealed no side effects and encourages us to recommend this method for other endoscopic applications. The method enhances our 3-D grasp of endoscopically examined lesions.