lasers Flashcards

1
Q
A
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2
Q

What does LASER stand for?

A

Light Amplification of Stimulated Emission of Radiation

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3
Q

What is spontaneous emission?

A

When a photon is applied to an atom, electrons gain energy and move to a high energy orbital, then emit a photon when returning to the ground state

If the photon is in the visible light spectrum, this is known as fluorescence.

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4
Q

What is stimulated emission?

A

Energised electrons act as energy sources for neighbouring atoms, leading to the release of 2 identical photons that are in phase with each other

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5
Q

What does population inversion refer to?

A

A sufficient number of atoms are energised, resulting in a majority of atoms with electrons in a higher energy state

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6
Q

What are the 3 properties of LASER light?

A
  • Monochromatic: One specific wavelength
  • Coherent: All waves are in phase
  • Collimated: Highly directional
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7
Q

Describe how a LASER works.

A

A lasing medium is pumped with energy to allow stimulated emission, with mirrors reflecting photons until population inversion occurs, and light energy leaks through a small opening to create a laser beam

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8
Q

What are the clinical applications of infrared lasers?

A
  • CO2 LASER: 10,600nm, absorbed by tissue water for bloodless cutting
  • Nd:YAG LASER: 1064nm, penetrates 3-5mm depth, used in dermatology
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9
Q

What are visible light lasers used for?

A

Argon LASER: 488-515nm blue-green, penetrates to 2mm, used for blood coagulation while avoiding transparent tissues

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10
Q

What are the different classes of energy in Lasers?

A
  • Class 1: Cannot emit radiation at any known hazard levels
  • Class 2: Low-power visible lasers, <1 mW
  • Class 3: Intermediate power, hazardous if directly viewed
  • Class 4: High power, >500 mW, very hazardous
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11
Q

What is Q switching?

A

A technique used to pulse lasers to allow heat dissipation and reduce destruction to neighbouring tissues

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12
Q

What safety mechanisms are needed when using class 4 lasers?

A
  • Appropriate training
  • Specific safety goggles
  • Environmental safety measures
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13
Q

When is there a particular risk with flammability and the use of Lasers?

A

During airway surgery, especially with high FiO2 or use of N2O

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14
Q

How can the risk of flammability during airway surgery be mitigated?

A
  • Use of modern volatile agents that are non-flammable
  • Reduced O2 concentration around the beam
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15
Q

What is the significance of reflected Lasers?

A

They are almost as powerful as the incident beam, necessitating the use of non-reflective instruments

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