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46 Cards in this Set
- Front
- Back
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Water
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700 to 2000
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Melanin
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300 to 1000
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Oxyhemoglobin
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300 to 1500
peak 400 and 550 |
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laser tissue interactions
measurements |
wavelength, fluence, irradiance, spot size, pulse duration,
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smaller spot size
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greater fraction of light is removed from the beam path by scattering ofphotons in outer portion
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effective depth laser
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penetrating wavelength 600 -1300 and large spot size
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cooling agent
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gas, liquid, solid
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cold gel
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passive cooling. no heat removal
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3 basic types of skin cooling
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1. precooling
parallel cooling postcolloing |
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parallel cooling
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most effecgive methogd for pulses longer than 5 -10 ms
no spray cooling interfers with laser pulse solid contactcooling w cold sapphire good for parallel cooling |
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post cooling
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minimilze erythema and swelling
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large vs small spot size
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larger spot size more photons remain within beam's diameter
smaller spot size greater fraction of photons scatters outside the beam and is ineffective penetrates deeper with larger spot size |
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CO2 laser
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10600 nm
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Er:YAG
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2940 nm
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Aragon laser
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488 and 514 nm
were used for vascular lesion until PDL strong absorption by melanin continuous wave lasers non-specific heating high risk scarring no longer commonly used |
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peak oxyhemoglobin
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yellow spectrum
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small caliber vessels port wine stain pulse duration?
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1 ms
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flashlamp-pumped PDL
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585 - 600
1.5 ms dynamic cooling w cryogen spray |
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port wine stain no respond to PDL?
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deeper than 1.5 mm
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deeper port wine?
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long pulsed neodymium:YAG (Nd:YAG)
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Standard treatment for vascular lesions
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585 nm flashlamp PDL
purpura dependent on fluence and spot size |
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PDL purpura?
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immediate microvascular hemorrhage
immediate micovascular hemorrhage thrombosis and delayed vasculitis 5 to 10 mm 4 - 15 J/cm2 if smaller spot size use need higher fluence use largest spot size if > 20 ms then no purpura, but do have caviation |
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Copper vapor or copper bromide lasers
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green 511 or yellow 578
15000 pulses per second quasicontinuous minimal sweling and crusting resolution 1 week |
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Potassium titanyl phosphate (KTP) lasers
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532 nm
telangiectasias w less purpura than PDLs crusting MC side effect, can have vesiculation use cooling |
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Eximer
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193 stratum corneum
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Erbium:YAG
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2940 stratum corneum
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CO2
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10600 stratum corneum to epiermis
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Aragon
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488-514
superficial papullary dermis |
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KTP
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532 mid papillary dermis
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PDL
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585-600 nm
superficial reticular dermis |
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Ruby
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694 deep reticular dermis
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Alexandrite
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755 deep reticular dermis
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Diode
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800 deep reticular dermis
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Nd:YAG
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1064 SQ fat
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melanosomes pulse rate
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70-250 ns
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melanosome laser?
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Q-switched
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Q-switched
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up to 10 J/CM2
694 nm deep red light 20 - 40 ns most tattoos except yellow and red dermal melanocytes nevus of ota solar lentigines ephelides cafe aut liat macules melanocytic nevi NO postinflamamtaor hhperpigmenation and mlelasma |
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Q-switched alexandrite
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755 nm deep red
50 - 100 ns |
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Q-switched Nd:YAG
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1064 nm energy in near-IR range
10 ns dermal melanocytes nevus of ota blue black tattoo can e doubled to a 532 visable green light by passing it through KTP crystal freq doubled ND:YAG remove epidermal melanin and red and yellow tatto ink NOT GREEN INK |
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hair removal laser
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Ruby
Aleandrite diode Nd:YAG |
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temporary hari removal
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lower fluenc and longer pulse durations
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microthermal treatment zones (MTZs)
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fractional
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confocal microscopy
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0.3 mm
resoliution 1 um S2 conventional microscopy |
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Filtered xenon flashlamps
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intense pulse light IPL
visable to near-IR range 480 -1200 nm filters 480 - 755 nm |
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OD
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OD= log (1/T)
T= transmitittance light through eyewar |
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mc fire lasers
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not putting in standby
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