Laser Flashcards
LASER- acronym
LASER means light amplification by stimulated emission radiation
Laser use
used to promote tissue healing , decrease pain and inflammation via NON-THERMAL mechanisms
Light definition
Light is defined as the emission of electromagnetic waves, made of photons traveling in space, in or close to the visible range of the spectrum
Laser (3 characteristics)
Invisible light energy in the visible red and near- infra red band of the electromagnetic spectrum
Monochromatic – 1 frequency only
Collimated/directional-non-divergent
Coherent - all waves in syncHow laser delivers energy
Lasers deliver energy in the form of electromagnetic radiation at specific frequencies and wavelength
The intensity of energy reaching the body is greatest when
the energy output is high
radiation source is close to the client
the beam is perpendicular to the skin surface
Monochromatic Light Therapeutic Advantage
absorption targeted to specific , wavelength dependent photoacceptor molecules, called chromophores, buried within soft tissue
Wavelength values
Visible light: ~400-650 nm
Infrared light: >650-1300 nm
Longer wavelength penetrates deeper
Photo Diodes
LEDs- light emitting diodes
SLDs-superluminous diodes
Laser diodes
Light emitting diodes-LED’s
produce low intensity light,
is not coherent or monochromatic
spreads widely
increases application time required
Supraluminous diodes-SLD’s
-produce high intensity,
almost monochromatic light, not coherent
spreads minimally
requires shorter application times than LED’s
delivers energy to wider area than laser diodes
Laser diodes
produce monochromatic, coherent and directional light
deliver energy to small specific area
LEDs
Most diffuse light
Widest frequency range
Low power individually
Best suited for treating large, superficial areas
SLDs
Less diffuse light
Narrower wavelength
Emit >power than LED’s
Best suited for superficial, moderately deep areas, based on wavelength
Laser Diodes
Provide single wavelength light
Very concentrated
Best suited to treat small areas
Delivers the most, deepest light to a single area of tissue
Power
The amt. of electromagnetic energy per unit time
Laser applicator power is measured in milliwatts
1mW=1/1000 of a watt
Preset on each applicator
Some units: Continuous vs. Pulsed
Laser diodes Power
5mW to 500mW
Energy
total amt. of electromagnetic energy delivered over entire treatment time.
Energy = power x time
1J = 1 W x 1 sec
The higher the power of the applicator, the shorter the treatment time
Energy Density
= power per unit area =J/cm2*
* Preferred clinical measure 2-30 J/cm2
Energy density for acute conditions
Acute and superficial conditions - use lower
energy doses
Energy Density for chronic conditions
Chronic and deeper conditions - use higher energy doses
Energy Density Parameters for soft tissue healing
5-16 J/cm2
Energy Density for Fracture Healing
5-16 J/cm2
Energy Density for acute arthrits
2-4 J/cm2
Energy Density for chronic arthritis
4-8 J/cm2
Energy density for lymphedema
1.5 J/cm2
Energy density for Neuropathy
10-12 J/cm2
Energy Density for acute soft tissue inflammation
2-8 J/cm2
Energy density for chronic soft tissue inflammation
10-20 J/cm2
Photobiomodulation
photochemical interactions between photons and healthy cells within and surrounding the soft tissue pathology
light unbinds nitric oxide, releases ATP, improves cell functions
chromophores
the light absorbing part of molecule that gives it color
best known chromophores
Hemoglobin (red blood)
Melanin (skin darkening)
Retinal rhodopsin (color vision)
light stimulates chromophores in mitochondria triggering..
Mitochondrial cytochromes which triggers the process of photobiomodulation and increases the oxidative metabolism of mitochondria
Clinical Indications for Lasers and Light
Soft tissue and bone healing Arthritis Lymphedema Neurological conditions Pain management
promotes use of LLLT for wound management, tendinopathies and pain
Effects of Laser and Light
Promote ATP production by mitochondria Promote collagen production by fibroblasts Modulate inflammation Inhibit bacterial growth
Wavelength LLT
600-904 nm
Contraindications
Malignancy Direct irradiation of the eyes Should always wear goggles opaque to the wavelength of the LASER Within 4 to 6 months after radiotherapy Radiotherapy increases tissue susceptibility to malignancy and burns Hemorrhaging regions May cause vasodilation and increase bleeding Over the endocrine glands May alter function of endocrine glands
Precautions
Low back or abdomen during pregnancy Epiphyseal plates in children Impaired sensation Impaired mentation Photophobia/light sensitivity Pretreatment with photosensitizer Acne medications
Adverse Effects
Transient tingling Mild erythema Rash Burning sensation Increased pain/numbness Burns from warm diode Fatigue
Implications of Laser
Laser is non-thermal = OK for acute conditions
Laser can be used for patients with metal implants and pacemakers
Modalities used before Laser
Ice
vasoconstriction decreases blood flow, improving light penetration
Modalities used After Laser
Massage, US, Estim
vasodilation increases blood flow, diminishing penetration of light
LLT Review (definition, purpose, use)
the application of low power light energy in the visible red and near-infra red band of the electromagnetic spectrum
for the purpose of photoactivating cellular mechanisms via process called photobiomodulation
leading to soft tissue repair and pain modulation
