Download Laser Therapy

Laser & Light Therapy
What is Laser Therapy?
• Light Amplification by the Stimulated
Emission of Radiation
• Compressed light of a wavelength from the
cold, red part of the spectrum of
electromagnetic radiation
• Monochromatic - single wavelength, single color
• Coherent - travels in straight line
• Polarized - concentrates its beam in a defined
location/spot
History
• Albert Einstein – 1st described this theory that was transformed in
to laser therapy
• By the end of the 60’s, Endre Mester (Hungary) – was reporting on wound healing through laser therapy
• In early 1960’s, the 1st low level laser was developed.
• In Feb. 2002, the MicroLight 830 (ML830) received FDA
approval for Carpal Tunnel Syndrome Treatment (research
treatment)
• Laser therapy – has been studied in Europe for past 25-30 years;
US 15-20 years
What’s in a Name?
• Therapeutic Laser
• Low Level Laser
Therapy
• Low Power Laser
Therapy
• Low Level Laser
• Low Power Laser
• Low-energy Laser
• Soft Laser
• Low-reactive-level
Laser
• Low-intensity-level
Laser
• Photobiostimulation
Laser
• Photobiomodulation
Laser
• Mid-Laser
• Medical Laser
• Biostimulating Laser
• Bioregulating Laser
What Does It Do?
• Laser light waves penetrate the skin with no heating
effect, no damage to skin & no side effects.
• **Laser light directs biostimulative light energy to
the body’s cells which convert into chemical energy
to promote natural healing & pain relief.
• Optimizes the immune responses of blood & has antiinflammatory & immunosuppressive effects.
Physiological Effects
• Biostimulation – improved metabolism, increase
of cell metabolism
– Increases speed, quality & tensile strength of tissue
repair
• Improved blood circulation & vasodilation
– Increases blood supply
• Increases ATP production
• Analgesic effect
– Relieves acute/chronic pain
• Anti-inflammatory & anti-edematous effects
– Reduces inflammation
Physiological Effects
• Stimulation of wound healing
– Promotes faster wound healing/clot formation
– Helps generate new & healthy cells & tissue
• Increase collagen production
– Develops collagen & muscle tissue
• Increase macrophage activity
– Stimulates immune system
• Alter nerve conduction velocity
– Stimulates nerve function
Tissue & Cellular Response
• Red light affects all cell types
– Absorbed by the mitochondrial present in all cells
– Cytochromes (respiratory chain enzymes) within the
mitochondria have been identified as the primary
biostimulation chromophores (primary light-absorbing
molecules).
– Since enzymes are catalysts with the capability of
processing thousands of substrate molecules, they
provide amplification of initiation of a biological
response with light.
• Infrared light is more selective absorbed by
specific proteins in the cell membrane & affects
permeability directly
Tissue & Cellular Response
• Cytochromes function to couple the release of
energy from cellular metabolites to the formation
of high energy phosphate bonds in adenosine
triphosphate (ATP)
– ATP is used to drive cell metabolism (maintain
membrane potentials, synthesize proteins & power cell
motility & replication).
• Assuming cytochromes also can absorb energy
directly from illumination, it is possible that
during LLLT light energy can be transferred to
cell metabolism via the synthesis of ATP.
Mitochondria
Tissue & Cellular Response
• Magnitude of tissue’s reaction are based on physical
characteristics of:
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Output wavelength/frequency
Density of power
Duration of treatment
Vascularity of target tissues
• Direct effect - occurs from absorption of photons
• Indirect effect – produced by chemical events caused
by interaction of photons emitted from laser & the
tissues
LASER Regulation
• LASERs - classified by the FDA’s Center for Devices
& Radiological Health based on the Accessible
Emission Limit (AEL).
• Class Levels 1-4
• 1 = incapable of producing damaging radiation levels (laser printers
& CD players)
• 2 = low-power visible lasers (400-700 nm wavelength, 1 mW)
• 3 = medium-power lasers - needs eye protection
• 3a – up to 5 mW
• 3b** – 5 mw-500 mW
• 4 = high-power lasers– presents fire hazard (exceeds 500 mW)
Laser Generators
• Components of a generator:
• Power supply – electrical power supply that can deliver
up to 10,000 volts & 100’s amps
• Lasing medium – gas, solid, liquid
• Pumping device –
– high voltage, photoflash lamps, radio-frequency oscillators or
other lasers (pumping is used to describe the process of
elevating an orbiting electron to a higher, excited energy level)
• Optical resonant cavity – contains lasing medium
Types of Lasers
• 4 categories of lasers
– Crystal & Glass (solid - rod)
• Synthetic ruby & others (synthetic ensures purity)
– Gas (chamber) – 1961
• HeNe, argon, CO2, & others (HeNe under investigation)
– Semiconductor (diode - channel) - 1962
• Gallium Arsenide (GaAs under investigation)
– Liquid (Dye) - Organic dyes as lasing medium
– Chemical – extremely high powered, frequently used for military purposes
High vs. Low Level Lasers
• High
• Low
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Surgical Lasers
Hard Lasers
Thermal
Energy – 3000-10000 mW
Medical Lasers
Soft Lasers
Subthermal
Energy – 1-500 mW
Therapeutic (Cold) lasers
produce maximum
output of 90 mW or less
– 600-1000 nm light
Infrared Light Therapy
• SLD – Super Luminous Diode
– Brighter
• LED – Light Emitting Diode
Laser Light Properties
• Monochromaticity
• 1 color – 1 wavelength
• <400 nm
• Ultraviolet spectrum
• Coherence
• Waves same length & traveling in same phase relationship
• 400-700 nm
• Visible
• Collimation
• Degree to which beam remains parallel with distance
• 700-10,000 nm
• Infrared
Parameters
• Patient
– Need medical history
& proper diagnosis
• Diabetes – may alter
clinical efficacy
– Medications
• Photosensitivity
(antibiotics)
– Pigmentation
• Dark skin absorbs light
energy better
• Laser
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Wavelength
Output power
Average power
Intensity
Dosage
Parameters - Wavelength
• Nanometers (nm)
• Longer wavelength (lower frequency) =
greater penetration
• Not fully determined
• Wavelength is affected by power
Parameters – Power
• Output Power
– Watts or milliwatts (W or mW)
– Important in categorizing laser
for safety
– Not adjustable
• Power Density (intensity)
– W or mW/cm2
– Takes into consideration – actual
beam diameter If light spread
over lager area – lower power
density
– Beam diameter determines power
density
• Average Power
– Continuous or pulse-train
(burst) frequency mode
– Knowing average power is
important in determining
dosage with pulsed laser
– If laser is continuous – avg.
power = peak output power
– If laser is pulsed (burst) then
avg. power is = to peak output
power X duty cycle
Parameters – Energy Density
• Dosage (D)
• Amount of energy
applied per unit area
• Measured in
Joules/square cm
(J/cm2)
– Joule – unit of energy
– 1 Joule = 1 W/sec
• Dosage is dependent
on:
– Output of laser in mW
– Time of exposure in
seconds
– Beam surface area of
laser in cm2
• Various dosage ranges
per site (1-9 J/cm2)
Parameters – Energy Density
• Recommended Dosage Range
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Therapeutic response = 0.001-10 J/cm2
Minimal window threshold to elicit response
Too much – suppressive effect
Open wounds – 0.5-1.0 J/cm2
Intact skin – 2.0-4.0 J/cm2
Average treatment – 6 /cm2
Helium Neon Lasers
• Uses a gas mixture in a pressurized tube
• Now available in semiconductor laser
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Emits red light
Wavelength: 632.8 nm
Power output: 1.0-25.0 mW
Energy depth: 6-10 mm
• The higher the output lasers (even though they
are still low power) allow reduced delivery time
Indium-Gallium-Aluminum-Phosphide
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InGaAip
Replacing HeNe lasers
Semiconductor
Wavelength: 630-700 nm
Power output: same as HeNe
Energy depth: superficial wound care
Gallium Arsenide
• Semiconductor - produces an infrared
(invisible) laser
• Wavelength: 904–910 nm
• Power output: may produce up to 100 mW
• Energy depth: 30-50 mm
• Short pulse-train (burst) duration (100-200 ns)
Gallium Aluminum Arsenide
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GaAIAs
Semiconductor
Wavelength: 780-890 nm
Power Output: 30-100 mW (up to 1000 mW)
Energy Depth:
What Does it Look Like?
• http://www.laserhealthsystems.com/omegao
fferings.htm
• http://www.thorlaser.com/products/
Indications
• Indications
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Soft tissue injuries
Fractures
Osteoarthritis, Rheumatoid Arthritis
Pain
Wounds & Ulcers
Acupuncture
Contraindications
• Contraindications
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Application over eyes
Possibly can damage cellular structure or DNA
Cancerous growths
Pregnancy – over & around uterus
Over cardiac region & Vagus nerve
Growth plates in children
Over & around thyroid gland & endocrine glands
Patients who have been pre-treated with one or more
photosensitizers
Treatment Precautions
• Better to underexpose than to overexpose
• Avoid direct exposure into eyes (If lasing for extended
periods of time, safety glasses are recommended)
• May experience a syncope episode during
treatment during chronic pain, but very rare
• If icing – use BEFORE phototherapy
– Enhances light penetration
• If using heat therapy – use AFTER phototherapy
– Decreases light penetration
Treatment Techniques
• Gridding Technique
• Divide treatment areas into grids of square
centimeters
• Scanning Technique
• No contact between laser tip in skin; tip is held 5-10
mm from wound
• Wanding Technique
• A grid area is bathed with the laser in an oscillating
fashion; distance should be no farther than 1 cm
from skin
• Point Application (Acupuncture point)
Treatment Techniques
• Simple
• For general application, only
treatment time & pulse rate
vary
• Dosage
• Most important variable in
laser therapy & may be
difficult to determine because
of the above conditions
• Handheld applicator
• Tip should be in light contact
with skin while laser is engaged
for calculated time
• Maintain laser perpendicular to
treatment surface
• Firm contact unless open
wound
• Clean area prior to treatment
• Begin with minimal treatment
and gradually increase
• Check for pre/post-treatment
changes
• Ask the patient how they are
doing prior to next treatment
– May have to adjust dosage
• Dynatron’s Solaris D880 Infrared Therapy
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880 nm wavelength – SLD (32 ) (deep)
660 nm – LED (4) (superficial)
10 minute max. treatment or 60 Joules
Place probe on treatment area. Maintain constant
contact with the skin.
• Do not bathe the area with the probe.
– FDA cleared to “provide topical heating for temporary
increase in blood circulation, temporary relief of minor
muscle & joint aches, pain & stiffness & relaxation of
muscles; for muscle spasms & minor pain & stiffness
associated with arthritis.”
• Dynatron Solaris 709
MedX Laser & Light Therapy
• Laser probe
• SLD (2)
Miscellaneous
• www.geocities.com/altmedd/laser.htm
• http://laserhealing.net/lowlevel.html
• Journal of Laser Therapy
– www.walt.nu/journal.htm