For both parts of the study, the subjects viewed the glottic opening using direct laryngoscopy followed or preceded by visualization of the glottic opening using the Trachview. The subjects were asked to score the amount of the glottic opening that could be visualized using the POGO (percent of glottic opening)score. Subjects were only given a very brief inservice on how to use the Trachview. Additional measurements such as presurgical airway assessments of the patients were obtained.