About Soft Lasers

Wiki Info
Low level laser therapy (LLLT, also known as photobiomodulation, cold laser therapy and laser biostimulation) is a medical and veterinary technique in which uses low-level lasers or light-emitting diodes to stimulate or inhibit cellular function.&lt;ref&gt;&lt;/ref&gt; The technique is also known by the more ambiguous terms laser therapy and phototherapy (though the latter more accurately refers to light therapy), which may also be used to describe other medical techniques. Basic research and work on specific treatments are being pursued with various modulations of wavelength, intensity, duration and treatment interval being tested.&lt;ref&gt;&lt;/ref&gt; The method is not yet accepted as routine medical therapy and evidence supporting its use is still inadequate.&lt;ref&gt;&lt;/ref&gt;

History
In 1967 a few years after the first working laser was invented, Endre Mester in Semmelweis University experimented with the effects of lasers on skin cancer. While applying lasers to the backs of shaven mice, he noticed that the shaved hair grew back more quickly on the treated group than the untreated group.&lt;ref&gt;&lt;/ref&gt;

Clinical applications
Clinical applications that show some potential of effectiveness include treating soft tissue injury, chronic pain, and wound healing. More uses include tinnitus and nerve regeneration. Resolution of viral and bacterial infections has been claimed, but no plausible mechanism for this has been proposed. A Cochrane Library review has concluded that there is insufficient data to draw a firm conclusion on the clinical effectiveness of low-level laser therapy for low back pain.&lt;ref&gt;&lt;/ref&gt;

Mechanism
Certain wavelengths of light at certain intensities (or irradiance to use the technically correct term) delivered by laser, LED or another monochromatic source may affect tissue regeneration, inflammation, or pain.&lt;ref&gt;&lt;/ref&gt; The exact mechanism is still being explored and debated but it is likely that the mechanism is photochemical rather than heat-related. Observed biological and physiological effects include changes in cell membrane permeability, up-regulation and down-regulation of adenosine triphosphate and nitric oxide.

The factors of wavelength, effective dose, dose-rate effects, beam penetration, the role of coherence and pulses (peak power and repetition rates) are still poorly understood in the clinical setting. Laser average power is typically in the range of 1-500 mW; some high peak power, short pulse width devices are in the range of 1-100 W with typically 200 ns pulse widths. The average beam irradiance then is typically 10 mW/cm&lt;sup&gt;2&lt;/sup&gt; - 5 W/cm&lt;sup&gt;2&lt;/sup&gt;. The wavelength is typically in the range 600-1000 nm (red to near infrared) but some research has been done and products are available outside this range.