1. Laser & Light Therapy

2. 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

4. 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 years; US years

5. What’s in a Name? Therapeutic Laser Low-intensity-level 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

6. 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 anti-inflammatory & immunosuppressive effects.

7. 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

8. 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

9. 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

11. 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.

12. Mitochondria

14. Tissue & Cellular Response
Magnitude of tissue’s reaction are based on physical characteristics of:
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

15. 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 ( 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)

16. 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

17. 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)
Gallium Arsenide (GaAs under investigation)
Liquid (Dye) - Organic dyes as lasing medium
Chemical – extremely high powered, frequently used for military purposes

18. High vs. Low Level Lasers
Medical Lasers
Soft Lasers
Subthermal
Energy – mW
Therapeutic (Cold) lasers produce maximum output of 90 mW or less
nm light
High
Surgical Lasers
Hard Lasers
Thermal
Energy – mW

19. Infrared Light Therapy
SLD – Super Luminous Diode
Brighter
LED – Light Emitting Diode

20. Laser Light Properties
Monochromaticity
1 color – 1 wavelength
<400 nm
Ultraviolet spectrum
Coherence
Waves same length & traveling in same phase relationship nm
Visible
Collimation
Degree to which beam remains parallel with distance
700-10,000 nm
Infrared

21. Parameters Patient Laser Need medical history & proper diagnosis
Diabetes – may alter clinical efficacy
Medications
Photosensitivity (antibiotics)
Pigmentation
Dark skin absorbs light energy better
Laser
Wavelength
Output power
Average power
Intensity
Dosage

22. Parameters - Wavelength
Nanometers (nm)
Longer wavelength (lower frequency) = greater penetration
Not fully determined
Wavelength is affected by power

23. Parameters – Power Output Power Power Density (intensity)
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

24. 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)

25. Parameters – Energy Density
Recommended Dosage Range
Therapeutic response = J/cm2
Minimal window threshold to elicit response
Too much – suppressive effect
Open wounds – J/cm2
Intact skin – J/cm2
Average treatment – 6 /cm2

26. Helium Neon Lasers Uses a gas mixture in a pressurized tube
Now available in semiconductor laser
Emits red light
Wavelength: nm
Power output: mW
Energy depth: 6-10 mm
The higher the output lasers (even though they are still low power) allow reduced delivery time

27. Indium-Gallium-Aluminum-Phosphide
InGaAip
Replacing HeNe lasers
Semiconductor
Wavelength: nm
Power output: same as HeNe
Energy depth: superficial wound care

28. Gallium Arsenide
Semiconductor - produces an infrared (invisible) laser
Wavelength: 904–910 nm
Power output: may produce up to 100 mW
Energy depth: mm
Short pulse-train (burst) duration ( ns)

29. Gallium Aluminum Arsenide
GaAIAs
Semiconductor
Wavelength: nm
Power Output: mW (up to 1000 mW)
Energy Depth:

30. What Does it Look Like?

31. Indications Indications Soft tissue injuries Fractures
Osteoarthritis, Rheumatoid Arthritis
Pain
Wounds & Ulcers
Acupuncture

32. Contraindications Contraindications 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

33. 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

34. Treatment Techniques Gridding Technique Scanning 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)

35. 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

36. Dynatron’s Solaris D880 Infrared Therapy
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

37. MedX Laser & Light Therapy
Laser probe
SLD (2)

38. Miscellaneous www.geocities.com/altmedd/laser.htm
Journal of Laser Therapy