Selection of the shape of the outer zone of the square field diaphragm in flexible endoscopes

Conclusions

1. Rounding off of the corners of the field diaphragm in flexible endoscopes with fiber optics and with a square light zone cross-section of the output ends of regualr braids at values of K equal to 0.38, 0.49, and 0.69 result in insignificant loss of the information content of the regular braid at the edge of the corner zone (3, 5, and 10% loss, respectively). This causes no practical decrease in the diagnostic capacity of the endoscope and permits a significant reduction in the diagonal dimension of the field diaphragm of 11.1, 14.3, and 20.1%, respectively, and a proportional reduction in the light and external diameters of the objective, as well as the length of the objective. It is thus possible to create a more compact distal head, which provides better maneuverability of the distal end of the endoscope in the cavity being examined, and also facilitates introduction of the endoscope into the cavity.

2. Selection of the value of K from the above series should take into account saturation of the distal head by structural elements.