Endoscopy Flashcards
How do more fibres affect endoscopy
- Higher Resolution
- Flexibility and tighter curves without losing light
How does total internal reflection work?
Light had to hit boundary at angle greater than critical angle
Equations for Critical angle
Sinc= core refractive index/cladding refractive index
What happens when you increase the refractive index of cladding??
Makes a larger critical angle so more light can escape
What happens if you bend the fibres in a tighter curve??
Internal angle will be less than the angle of incidence at the core cladding boundary so light escapes
Coherent bundle -
Structure+ job
- Fibres in same relative location at both ends of the bundle
- Transmit the image of internal organs in the body
Incoherent Bundle
Structure+ Job
- Fibres in no fixed relative position
- Transmit light in to the human body to illuminate the organs
Why is cladding used
3 reasons
- Protects the fibres from getting scratched
- Stops light escaping from escaping from scratches
- Prevents cross talking
Cross talking definition
When a ray leaves one fibre and enters another.
- Lowers the resolution and blurs image
Laser light properties
- Monochromatic- same wavelength and F
- Collimated- parallel beams
- Coherent waves- in constant phase with each other
Uses of filament light in endoscopy
Illuminates inside of the body
Uses of laser light In body
- Stop bleeding
- Cutting tissues
- Treating tumours
Keyhole Surgery-what is it ?
Uses endoscopy with surgical attachments to perform operations through small holes
Advantages of Endoscopy
- Low risk of infection
- Greater recovery rate
- cheap
- Better cosmetics results( no scars)
Disadvantages of Endoscopy
-invasive
