84. Fiber-optic Endoscopes, Videoendoscopes, Construction and clinical importancerename
yaboiemil's version from 2016-02-14 22:17
Section1. A fiber-optic cable exploits total internal reflection in order to transport information through it.
2. Total internal reflection occurs when a propagating wave strikes a medium boundary at an
angle larger than a particular critical angle and the refractive index is lower on the other side of
the boundary, rendering the wave unable pass through and is entirely reflected.
3. A fiber-optical cable will have a cross section that looks like this:
Where the inner ring (n1) will have a higher index of refraction that the outer ring (n2), enabling
total internal refraction.
4. In an endoscope, there are usually 2 optical fibres - one for LIGHT transmission and one for
5. The endoscope will also have other components, such as air or water channels to permit the taking
6. There is a viewing objective at the distal end
7. There is a viewing ocular at the proximal end
8. There is mechanical control at the proximal end
9. The light source is Halogen or Xenon
10. With a Videoendoscope, the viewing objective is replaced with a camera. The image can be examined
on a TV.
Remember dis u ho:
|Total Internal Reflection||Angle of incidence > Critical Angle & Refractive Index Lower on other side.|
|Proximal End of Endoscope||Viewing Ocular and Mechanical Control|
|Distal End of Endoscope||Viewing Objective|
|Light source of Endoscope||Halogen / Xenon|