laser Flashcards
what is laser
monochromatic , coherent and collimated light
once in tissue it refracts, diverges and reflects
ABSORBED
monochromatic, cohert and collimated - whats most important
mono
observed responses to laser
inc ATP production
inc collagen production
dec inflammation
dec bacterial growth
vasodilation
accelerated wound healing
how does laser work
laser photons are absorbed by chormopores
proposed therapeutic effects of laser
tissue healing
pain/inflam reduction
chromophores
organic molecules that absorb light
too much ROS signalling results in
cell apoptosis
whats ROS signalling do
inc ca flow
cellular growth
MAPK activation
LLLT ____ ROS in oxidative stressed cells and tissues
reduces
LLT ____ levels of pro-inflammatory cytokines
reduces
MAPK pathways do what
+ca signalling
secretes growth factors
Nitric oxide signalling does what
vasodilation
modulates inflammatory response
produces growth factors
cellular response from laser
protein translation cell proliferation attachement survival dec inflam response
how does laser reduce inflam
reduces levels of pro inflammatory cytokines in activated inflammatory cells
T/F laser is an anti inflammatory
t
how does laser help with pain
locally it reduces inflammation
centrally it releases endorphins if used over acupuncture point
is laser shown to work better with acute or chronic pain
chronic
does laser help with RA and OA
yes, more evidence of RA
Class I-III laser MW amount
up to 500mW
Class IV lasers produce
10-15W
units for laser
J/point
joules per pint
1 joule = watt/sec
1
10mW applied for 100 s delivers how many joules
1
0.01W x 100s
photoreceptors are what colour
blue and green
laser ___ prostaglandin E2 concentration, ____ cycloxygenase in vitro, ____TNFa, ____ mitchondrial ATP
reduces
inhibites
reduces
increases
better evidence for management of ___ MSK than _____ pain
chronic
acute
power equation
how many joules/sec = 1 watt
energy density formula
Mw/cm x seconds = J
power density equation
fixed for each device Mw/cm2, W for class 4
1W laser applied to 1 second = how many joules
1 becuase
joules = watts.second
10mW applied for 100 s deliver hows many J
1 because mW, put it into decimal (.01W)
key to energy density equations
use cm
joules calcualtion
Watts x seconds
total energy calcualtion
W x sec
recommended way of recording dose is
joules per point
1 depth of penetration
point where energy is reduced to 37% of original value (i.e 63% absorbed)
T/F labs suggest 0.01 J/cm can alter cellular response
true
t/F laser therapy typicalyly involved 4J/cm2 per treatment of surface
t
decisions you make when applying laser
colour
dose
application technieu
___ determines the depth of penetration
colour
energy delivered formula
power x time
mW x s
calculating laser dose
Joules / watts = seconds
modes of application laser
contact (point, grid) non contact (scanning, grid)
is contact or non contact better
contact
should you cleanse the skin w alcohol before laser
yes or soap and water
is eye protection needed for laser
yes
contraindications for laser
eye malignancy back/ab of preg hemorrhage, vascular condition TB active bleeding disorder active DVT balls
precautions for laser
infected areas
epiphyseal plates
anterior neck
cognitive impairment
safety guidelines for doing stillt
controlled area eye protection authorized only warning sign windows covered
class IV laser differences
larger areas may be covered during short application
some warmth
greater depth
still reseraching
