Chapter 2 - Endoscopy

Question 1

What are the two branches of optics?

Answer 1

• Geometric (Ray) Optics?
• Wave Optics?

Question 2

What does geometric optics focus on?

Answer 2

• How light travels in various materials
• How it interacts with various materials
• How it can be manipulated to perform various functions

Question 3

What does wave optics focus on?

Answer 3

Studies the wave-like properties of light: Interference, diffraction, polarization, etc.

Question 4

What happens when light enters a medium with a slower speed (higher n-value)?

Answer 4

The angle of refraction will be smaller than the incident angle

Question 5

What happens when light enters a medium with a faster speed (lower n-value)?

Answer 5

The angle of refraction will be larger than the incident angle.

Question 6

What are the two main components of optical microscopes?

Answer 6

• The objective lens: a small lens that creates a slightly larger, inverted, real image
• The eyepiece lens: A larger lens that takes the real image produced by the objective lens and magnifies it, creating a large virtual image. The orientation is the same as the real image of the objective lens.

Question 7

What are optical fibers?

Answer 7

Devices that allow us to guide light along winding pathways

Question 8

When can total internal reflection occur?

Answer 8

When light enters a medium with a LOWER index of refraction. (A medium with a faster speed of light)

Question 9

What is the typical structure of a fiber optic cable?

Answer 9

• Core
• Cladding
• Buffer
• Jacket

Question 10

What is cladding used for in fiber optics?

Answer 10

Cladding is used to coat optical fibers in a glass of lower index of refraction to allow TIR. The cladding is then covered in tough plastic (buffer) to protect it.

Question 11

What is a coherent fiber optic bundle?

Answer 11

A bundle of individual fiber optic cables that preserve their orientation throughout the entire cable, which allows images to be transmitted.

Question 12

What is an image conduit?

Answer 12

A fiber optic bundle that can transmit images. (Must be a coherent bundle)

Question 13

What are incoherent fiber optic bundles?

Answer 13

FIber optic bundles that do not preserve their orientation. They can not clearly transport images and are only used for illumination.

Question 14

What is the spatial resolution of an endoscope?

Answer 14

The size of individual fibers limit the resolution of the image produced. The smaller the fiber, the higher resolution of image is produced.

Question 15

What are some advantages of endoscopy?

Answer 15

• Reduced Hospital Stays
• Faster recovery time
• Reduced risk of infection
• Reduced risk related to general anesthesia
• Reduced invasiveness

Question 16

What are some disadvantages of endoscopy?

Answer 16

• Laparoscopic procedures require inflating the abdomen which can be uncomfortable for the patient
• Endoscope use is not intuitive and surgeons must receive extra training to use them
• Video monitors lack depth and important features may be hidden from view
• Lack of feedback - surgeon doesn’t know if they’re applying too much force
• Overall costly for the medical industry (cheap procedures but there are so many that it gets expensive)

Question 17

What is the name of a gallbladder removal surgery?

Answer 17

Cholecystectomy

Question 18

What is an endoscope?

Answer 18

A class of medical instruments that have a long, slender tube, capable of transmitting images and light in the body that otherwise would require open surgery

Question 19

What are sigmoidoscopes and colonoscopes used for?

Answer 19

Colon cancer screening

Question 20

What are laparoscopes used for?

Answer 20

Abdominal surgery

Question 21

What are arthroscopes used for?

Answer 21

Surgery for knee, shoulders, and other joints