Chapter 1: Introduction To Photothermolysis Flashcards

1
Q

What does Laser stand for?

A
Light
Amplification
Stimulated
Emission
Radiation
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2
Q

What is laser light? (The electromagnetic spectrum of radiation)

A

Laser light is really a sophisticated method of converting light into energy for use as in devices with many applications in nearly every major industry

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3
Q

What is sunlight?

A

Sunlight is a beam or a ray of light that is made up of a variety of invisible and visible forms of electromagnetic energy
—commonly called EM energy

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4
Q

What is a wavelength?

A

It is measured from the distance from the top of one wave (amplitude) to the top of the next.

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5
Q

Visible Spectrum of Light:

A
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6
Q

Light is measured by its _____________ in _____.

A

Wavelength in nanometers.

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7
Q

What is the wavelength of violet light?

A

400nm-420nm

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8
Q

What is the wavelength of Indigo?

A

420nm-440nm

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9
Q

What is the wavelength of Blue?

A

440-490nm

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10
Q

What is the wavelength of green?

A

490nm-570nm

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11
Q

What is the wavelength of yellow?

A

570nm-585nm

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12
Q

What is the wavelength of orange?

A

585nm-620nm

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13
Q

What is the wavelength of red?

A

620nm-780nm

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14
Q

What is one wavelength equal to?

A

One wavelength equals the distance between two successive wave crests or troughs

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15
Q

What is Ionizing radiation (ionizing vs non-ionizing radiation)

A
  • occurs at short wavelengths <400nm
  • strips the elctrons from transport media
  • alters cellular function
  • causes mutation on DNA (ex: X-rays, ultraviolet UV rays)

Http://youtu.be/rApXQmkpk-Q

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16
Q

What is non-ionizing radiation? (Ionizing vs. Non-ionizing radiation)

A
  • it can NOT strip electrons from transport media
  • can NOT alter cellular function
  • greatest risk is Ocular (eye) damage. (Ex: medical lasers, IPL machines)
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17
Q

Properties of laser light:

A
  • lasers have unique properties that are not seen in any other type of energy form
  • normal white light (flashlight or light bulb) is made of a multitude of visible and invisible infrared wavelengths merged and created white light that’s can quickly disperse in space within a short distance.
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18
Q

What are the 4 effects laser light can have on tissue of the skin (tissue effects)

A
  1. Absorption
  2. Reflection
  3. Transmission
  4. Scatter
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19
Q

What is photothermolysis (how do we use light energy?)

A
  • the absorption of light by chromosphere’s (hemoglobin, melanin or water)
  • the transformation of absorbed light into heat (thermo)
  • the breakdown of cells (lysis)
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20
Q

What is a chromophore?

A

Melanin, Collagen, Hemolglobin, and water

Particles in our body which absorb light

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21
Q

What are the 5 parameters of photothermolysis?

A
  1. Wavelength
  2. Pulse width (pulse duration)
  3. Exposure time
  4. TRT: thermal relaxation time
  5. Fluence
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22
Q

What is a wavelength?

A

-the distance between two successive wave crests or troughs

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23
Q

What is Pulse width (pulse duration)?

A

-the amount of time the laser is emitted on the skin measured in nanosecond and millisecond.

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24
Q

What is Exposure Time?

A

-should be less than or equal to the time necessary for cooling of the target structure

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25
Q

What is TRT

A
  • thermal relaxation time of a mass is the time required for it to cool down to the normal temp of the surrounding tissue
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26
Q

What is fluence?

A

-the energy delivered per unit area

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27
Q

What is the process of selective photothermolysis?

A
  • The use of light energy to target a particle that’s is in our body which absorbs light.
  • These particles are called chromophores
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28
Q

Chromophore facts: (2)

A
  • there are many types of chromophores

- studies have mapped the wavelength absorption of each chromophore

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29
Q

Selective Photothermolysis is achieved by: (3)

A
  1. Wavelength
  2. Pulse width/ duration

Thus causing…

  1. Exposure Dose/ Joules
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30
Q

How is photothermolysis achieved through wavelength?

A

-selective absorption- the longer the wavelength, the deeper the penetration

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31
Q

How is photothermolysis achieved through pulse width/ duration?

A
  • heat confinement
  • pulse duration is measure in nanoseconds (ns) or milliseconds (ms) it is the timing of the light energy or how long the laser is actually on the skin
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32
Q

How is photothermolysis achieved with exposure dose/ joules?

A

-fluence refers to the energy of the pulsed laser beam it is expressed in joules per square centimetre (J/CM2) and refers to energy x time

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33
Q

Energy absorption targeting 3 main chromophores:

A
  1. Melanin
  2. Hemoglobin
  3. Water
34
Q

5 components of photothermolysis:

A
  1. Wavelength
  2. Joules
  3. Pulse width
  4. TRT
  5. Cooling
35
Q

Light transmits ___________

A

Energy

-it is an electromagnetic wave that carries energy

36
Q

What is the wavelength range of visible light? (Light characteristics)

A

400nm - 700nm (visible light)

37
Q

Wavelength diagram (another example)

A
38
Q

Electromagnetic Scale Diagram:

A
39
Q

What is the “secret” or key to the creation of laser light?

A

-the secret to the creation of laser light lies within a machines general design, computer software, cooling system and optics

40
Q

What is an optical resonator?

A
  • Within every laser device is a tube or optical resonator

- the resonator contains a medium, usually a gas, solid or liquid, that is responsible for the creation of light

41
Q

What is a resonator containing medium made of?

A
  • a gas medium can be made up of argon, carbon dioxide, or helium-neon gas particles
  • a solid medium is usually a synthetic crystal made up of yttrium aluminum garnet (YAG) particles and then doped with certain elements such as holmium, neodymium, and thulium or erbium electrons.
  • Lasers are named in reference to their medium
42
Q

Describe how turning on a laser machine creates laser light:

A
  • turning on a laser machine creates a high voltage electricity that stimulates an intense light source from within that stimulates an intense light source from within the machine.
  • the electrons within the laser medium becomes stimulated by this electricity, then collide with mirrors placed on opposite ends of the laser tube and spontaneously produce identical photons.
43
Q
  • turning on a laser machine creates a high voltage electricity that stimulates an intense light source from within that stimulates an intense light source from within the machine.
  • the electrons within the laser medium becomes stimulated by this electricity, then collide with mirrors placed on opposite ends of the laser tube and spontaneously produce identical photons.

As a result…

A

All of the photons travel at the same frequency, parallel to each other and in phase in a collimated, coherent, monochromatic beam of light.

44
Q

Properties of laser light: (3)

A
  1. Coherent light
  2. Monochromatic Light
  3. Collimated Light
45
Q

Define Coherent light: (properties of laser light)

A

This means that all the light waves are travelling in the same direction and in unison with each other.

46
Q

Define monochromatic light: (properties of laser light)

A
  • normal light contains all of the visible colors of light and appears white.
  • when light is passed through a prism or water droplet, one can actually see the full spectrum of visible light in a rainbow
  • laser light referred to as monochromatic (mono means one) it is made up of one wavelength and one colour and can be wither visible or invisble
  • each different colour of light acts differently when exposed to different tissue and will create a unique clinical effect
47
Q

Describe a Ruby Laser device:

A
  • 694nm
  • highly melanin attraction
  • best suited for skin type I and II (very light skin)
  • not penetrate as deeply as other laser machines
  • less effective for deep follicles and dark skin
48
Q

Describe an Alexandrite laser device:

A
  • 755nm
  • 2nd highest melanin attraction
  • effective in skin type I to IV
  • using cooling system specially for darker skin type (IV)
  • most devices have a built in cooling system
49
Q

Describe the Diode Laser 810nm

A
  • Has variety of pulse duration (pulse width)
  • Effective on all skin types
  • Long term hair reduction
50
Q

Describe the ND-YAG 1064:

A

Doesn’t have high melanin attraction

  • very safe for darker skin type
  • long pulse ND-YAG laser can penetrate 3-5nm deep. Higher fluence and aggressive cooling is needed in order to see the best result without damaging surrounding skin
  • ND-YAG causes more discomfort due to deep penetration
51
Q

Describe Tattoo removal lasers:

A
  • due to absorption curve of laser versus the different colours of tattoo ink, each colour mayu require a different laser for proper clearance.
  • The result is not guaranteed and fair amount of trauma to the skin is necessary for deep tones
52
Q

Describe Q-Switched ruby laser device

A
  • 694nm

- clears green, black and blue pigment (multiple treatment required)

53
Q

Describe the Q-switched Alexandrite Laser

A
  • 755nm

- ALSO CLEARS GREEN, BLACK AND BLUE PIGMENT AND REQUIRES MULTIPLE TREATMENTS

54
Q

-Describe Q-switched ND:YAQ Laser

A
  • 1064nm
  • Treats black and blue pigment and has an advantage over the Alexandrite because it can be used on darker skin types
  • although the YAG is an effective device, blistering, bleeding, and bruising are often some of the side effects of the treatment
55
Q

What is IPL?

A
  • stands for INTENSE PULSE LIGHT (quite different from a laser)
  • a computer generated system which emits a broad spectrum of light wavelength from 420nm-1200nm.
56
Q

In IPL, what are cut off filters used for?

A
  • cut off filters are used to block out WL’s of a light below the filter number selected and only those WL’s of light above the filter numbers to pass through
  • IPL system is very versatile
57
Q

Describe how IPL effects or treats chromophores:

A
  • one wavelength is absorbed by a chromophore, heat is released
  • has an advantage of treating more than one specific chromophore at the same time
58
Q

Describe the IPL light source, and wavelength spectrum:

A
  • it is high intensity light source which emits polychromatic, non coherent light
  • IPL has a broad wavelength spectrum (420-1200nm)
59
Q

Does IPL emit incoherent or coherent light?

A

-Laser emits monochromatic, coherent light

60
Q

Depth of penetration diagram:

A
61
Q

Colour coded hand pieces: Blue:

A

Acne (AC 420)

62
Q

Colour coded hand pieces: Green:

A

Pigmented and Vascular Skin (DUAL VP)

63
Q

Colour coded hand pieces: Yellow:

A

Skin Rejuvenation (SR 580)

64
Q

Colour coded hand pieces: Red:

A

Hair reduction (HR 365)

*each light (wavelength) will penetrate skin differently. Blue is most superficial and red is deeper

65
Q

What is Light Intensity defined by?

A

-Light intensity is defined by the energy density FLUENCE, which is measured in joules per centimetre squared (J/cm2)

66
Q

What can joules be compared to?

A

-sun rays. It is how much energy/ heat is being delivered to the skin

67
Q

How do darker skin or clothing influence energy absorption?

A
  • The darker the skin or clothing, the more optical energy (light) is absorbed
  • darker surfaces heat up faster, thus they require a lower fluence
68
Q

What are joules?

A

-The unit of measurement used to describe the intensity (fluence) of the light energy per cm2

69
Q

Joules can also be referred to as ______ or _______ _______.

A

Fluence or light energy

70
Q

Fluence or energy density refers to:

A
  • the amount of optical (light) energy delivered to a certain area measured in J/cm2
  • It defines the intensity of the light pulse
  • The technician will dictate in parameters, on your sharpLight modality, as to how many joules will be used during the treatment
  • They may be increased or decreased depending on the clients skin type and comfort level
71
Q

What is Pulse duration?

A

Pulse duration = conduction/ induction
-the pulse duration/ pulse width determines the aggressiveness of the treatment and is often measured in milliseconds (ms)
—the unit of measurement can vary depending on the technology being used

72
Q

What are we heating and how are we heating it? (Short vs long pulses)

A

-shorter pulses are more aggressive and longer pulses are less agressive

73
Q

Are longer or shorter pulses safer for darker skin?

A
  • For dark skin and hair, longer pulses are safer

- for light skin and hair, short pulses are more effective

74
Q

DPC technology allows you to:

A
  • offer your client a personalized treatment that will cater to their needs effectively and safely
  • our goal is to be specific. It is important to achieve a therapeutic temperature only in the targeted area, while leaving the surrounding tissue intact.
75
Q

When was selective photothermolysis developed?

A

-in 1983 by Anderson and Parrish
-relates to the correct use of chromophore:
—wavelength selection for specific chromophore
—bigger impact lesion
—selectively achieve damage temperature only on lesion

76
Q

What is “our mission”?

A
  • to be specific
  • to provide selective treatment where we achieve therapeutic temperature only in the targeted tissue, while leaving the surrounding tissue intact

Problem: Selective heating =/ specificity
On one hand: chromophore selective heating
On the other hand: heat conduction to healthy tissue

Solution: Thermal Relaxation Time (TRT)

77
Q

What does TRT mean?

A

Thermal Relaxation Time
-the time it takes the heat to conduct away from the lesion

For example:

  • If TRT = 1 sec
  • After 1 sec of heating, we will damage healthy tissue
78
Q

What should be done to specificity to protect the tissue?

A

-increase specificity to protect the tissue

79
Q

What are the benefits of cooling?

A
  • Higher cooling= higher specificity

- Cooling slows heat conduction to the healthy tissue

80
Q

Clinical manifestation of cooling:

A
  • decreases heating rates on healthy tissue
  • the heating of the lesion is not effected
  • the lesion will heat up fast where as the healthy tissue will heat up slow, therefore the different rates of heating improve specificity
81
Q

Describe contact cooling hand pieces:

A

-contact cooling prevents superficial skin burns, adds comfort to the patients treatment and provides added confidence to the practitioner

82
Q

Effect of contact cooling on the skin diagram:

A