Upper Gastrointestinal Endoscopy
A. The endoscope is advanced down the relatively straight esophagus until the lower esophageal sphincter is identified. B. The lower esophageal sphincter often coincides with the transition from squamous epithelium (white) of the esophagus to mucosa (pink
Minor Tip Deflection with gentle advancement
A. Minor tip deflection with gentle advancement and mild torsion allows the endoscope to traverse bends while maintaining a gentle curve. B. Sharp angulation of the tip (like a candy cane) hinders advancement and may result in paradoxical motion, where th
Rotating wheels on the headpiece of the endoscope
Rotating wheels on the headpiece of the endoscope control tip deflection. Instruments may be passed through an access port, which is kept capped when not in use (to prevent loss of insufflation and splashing of fluids).
Assuring Internal Reflection
A. Internal reflection is assured by cladding each fiber with a coating of high refractive index. Virtually all light is reflected back and forth within the fiber with little loss. B. The image produced by a fiberoptic endoscope is composed of a multitude