LASER Flashcards
LASER stands for
light amplification by stimulated emission of radiation
what is population inversion
oscillation between ground and excited state to create energy within the body
what is spontaneous emission without population inversion vs with it
w/o - normal light
with - LASER
explain coherent vs incoherent LED light
coherent = all light in uniform direction
incoherent = light not in uniform direction
what is monochromacity
light produced at single wavelength
that is infrared (invisible) or in the visible light spectrum (red)
what does tissue absorbance depend upon?
wavelength of laser light
explain how LASER light is initiated and projected
imagine two sides with mirrors facing each other
energy moves back and forth from mirror to mirror until it all becomes monochromatic
once it all is lined up, the selective filter mirror allows for it to be emitted from the vacuum
what class of LASER is used in therapy
Class 3
- low level laser or “cold” laser
what are the subclasses of class 3 lasers
3a = Helium Neon <5mW
3b = Helium Neon 5-500mW
thermal effects of hot lasers
elevation of tissue temperature (no kidding!)
dehydration of tissue
coagulation of protein
thermolysis
evaporation
cold LASER physiological effects
increased:
oxidative phosphorylation
bactericidal effect
leukocyte activity
DNA/RNA synthesis
calcium fluxes
fibroblast growth / collagen deposition
re-epithelization
angiogenesis
what is low-level LASER typically used on
painful / inflammatory neuromusculoskeletal conditions
clinical application of LASER
edema reduction
wound healing
pain relief
carpal tunnel syndrome
explain how LASER assists wound healing
chronic/surgical wounds
- bactericidal effect can decrease infection
increase collagen synthesis/strength
decrease scar formation
what is LASER typically used for in relation to pain relief
RA joints
trigger points
tendonitis
joint pain
what are the application techniques for LASER
gridding
surround
explain gridding LASER application technique
cover a 1-1.5 cm² area with direct skin contact
go from square to square like a grid
explain surround application technique of LASER
in hopes to stimulate periphery of wound
cover a 2cm² area for 30seconds
what is LASER measured in regarding power
Joules = watts (J/sec) x time (sec)
what is power measured by in pulsed LASER application
rate x peak power x pulse width
what is energy density measured in
joules/cm²
Gas LASERs are composed of
Helium and Neon
HeNe have a _______ of:
- wavelength
- power
- divergence
632.8 nm
1-10 mW
18-21°
semiconductor LASERS are composed of
Gallium Arsenide (GaAs)
GaAs LASERS have a ______ of:
- wavelength
- power
- divergence
904 nm
peak power = 2 W
avg power = 0.4mW at 1000 Hz
10-35°
how is average power calculated
pulse rate x peak power x pulse width
depth of penetration of NeHe LASER
direct = 2-5 mm
indirect = 8-10 mm
depth of penetration of GaAs LASER
direct = 10-20mm
indirect = 50 mm
precautions / contraindications of LASER
infection
abnormal sensation
malignancy
epilepsy (no C-Spine)
no growth plates
fever
acute hemorrhaging/active bleeding
documentation of LASER therapy
location of treatment
dosage (joules/cm²)
laser power (watts)
duration of treatment
frequency / type of laser used
mode (continuous or pulsed)
pre/post treatment assessments
