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Choosing a Low Level Laser
The FDA has approved many types of cutting lasers for both medicine and dentistry, and, in February, 2002, approved one product for treatment of carpal tunnel. The FDA classifies all lasers, whether they are industrial or medical, according to their radiation hazard, as either Class 1, 2, 3, or 4, with subdivisions of some of the classes. The FDA also requires lasers used for treating humans to be classified under the Medical Devices Division. Getting the laser classified here is much more difficult because the FDA requires efficacy studies or proof that the lasers do work and they do what the manufacturer claims, without harming the patient. The Radiation hazard classification is determined by potential risk to the eye. There are several factors that enter into this determination which aren’t really important to our discussion here. To accurately measure a laser for eye risk, the laser — measuring instrument is placed 20 centimeters from the light beam source. If the laser beam is not collimated but allowed to diffuse, it is very safe. Low Level Lasers, Inc. has registered industrial lasers that have been classified as Class 1 based on testing done by Underwriters Laboratory.
Worldwide research has shown benefit from LEDs as well as true laser diodes. LEDs are light emitting diodes and basically are different colored miniature light bulbs. They are inexpensive and are used extensively in industry. Some companies have made clusters of LEDs for human use. The FDA does not regulate LEDs in the same manner as laser diodes; therefore, companies can advertise their product as FDA approved. Unfortunately many people are lead to believe that these LEDs are lasers. This is not the case and is not true. They are not true lasers and do not provide the same benefits. Some companies that sell LEDs for medical use are listed on the following web sites:
http://www.light-force-therapy.com
http://www.lasercomb.net/benefits.htm
In general a low level laser is considered anything below 1 (one) watt of power regardless of the wavelength. Remember 1 watt is the same as 1000 milliwatt, written as 1mW. Wavelengths are measured in nanometers or 1000th of a meter, written as 1nm. Red visible light is in the range of 632 to 670nm. Near infrared wavelengths (which can be seen faintly in a darkened room) are in the range of 680 to 790nm. Infrared wavelengths range from 800 to 1000nm. Either LEDs or true laser diodes can deliver all these wavelengths.
Some differences between LEDs and true laser diodes are:
• LEDs are brighter and emit light in a round circle.
• LEDs to be effective must be run at higher powers.
• LEDs are much cheaper than true lasers, and LED units can be bought all the way from $150 to $300 and up. The actual cost of a single LED ranges from $.15 (cents) up to $.45 therefore clusters of LEDs would only cost the manufacturer a few dollars.
• True laser diodes that are not colluminated emit light as a narrow linear band.
• True lasers that are colluminated produce light in a spot similar to a laser pointer. This type of laser works best for acupuncture.