Repeatable characteristics of the spatial directions in the view of the endoscope / 中国耳鼻咽喉头颈外科

ABSTRACT

OBJECTIVE To know the principles of the transformations of the spatial directions in the view of the 0~ sinus endoscope and to simulate the space in endoscope using SkechUp software. METHODS The ideal model of the nasal cavity was designed and observed by the 0?rod-lens telescope. The space of the model in the endoscope was simulated using SkechUp.The principles of the transformations of the spatial directions were observed,which consisted of the lateral horizontal line (Lhn,n=0-6),the lateral vertical line (Lvn,n=0-9),the top horizontal line (Thn, n=0-9) and the lateral angle line (LAL).The location of the horizon was observed.RESULTS If the elevation angle (between the endoscope and bottom of nasal cavity) of the endoscope entering the model was unchanged and the distance of the endoscope entering the model was increased gradually,the positions of Lhn,Lvn and Thn in the visual field of the endoscope were replaced by Lh (n+1),Lv (n+1) and Th (n+1) respectively.The positions of Lhn,Lvn and Thn had repeatable characteristics.One horizontal plane in the space can become a horizon in the view and the location of the horizon in the view was invariable.If the distance of the endoscope entering the model was unchanged,the endoscope was moved to produce15?,30?,45?,60?elevation angle gradually,the positions of LAL (15?,30?,45?,60?) had the symmetry and repetition and the position of the horizon in the view was variable.CONCLUSION The directions of Lh and Lv and the locations of the horizon in the view of the 0?endoscope are correlative with the elevation angle of the endoscope,not pertinent to the distance of the endoscope coming into the nasal cavity.The directions of the space in the visual field of the endoscope have the symmetry and repeatable characteristics.Simulating the space in the visual field of the endoscope using SkechUp software provides the bases for the operation.