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LEDs (Light Emitting Diodes)
Leimo is the world's first and only personal use laser hair comb to use both laser and
LEDs (Light Emitting Diodes) this combination gives users the best of both world in one single device.
LEDs have far less power density (W/cm²) than lasers and LEDs is
non-coherent. However LEDs are also monochromatic (single colour) liken to
lasers , although the wavelengths of LEDs are of a broader spectrum.
There are beneficial effect from LED Therapy (LEDT), although LED is non-coherent, but many clinical studies have shown the effectiveness of LED.
According to Jan Tunér, DDS and Lars Hode, Dr Sci. leading pioneers of laser therapy
in their latest and most up to date book on laser therapy Laser Therapy - Clinical Practice and Scientific Background " the point to note is not that LEDs is not working but that when compared with Lasers , it seems that one can always obtain a better results with Lasers than with LEDs."
Which is better ? Coherent or Non-coherent ?
One of the arguments on Laser vs LED is on the coherence
of each light source. Lasers light are coherent and LED's are
Non-coherent. One manufacturer of a laser hair device goes all the
way to state that it is the coherence of laser light that produce
biological changes . But is this the
correct objective view or simply a subjective argument without stating the
facts ? A study done by the Mayo Clinic in 1989 suggests that the results of light therapy are a direct effect of light itself, generated at specific wavelengths, and are not necessarily a function of the characteristics of coherency and polarization associated with lasers.
[1]
In a study entitled Low-Energy Laser Therapy: Controversies and New Research Findings, Jeffrey R. Basford, M.D. of the Mayo Clinic’s Department of Physical Medicine and Rehabilitation, suggests that the coherent aspect of laser may not be the source of its therapeutic effect. He states "firstly, the stimulating effects (from therapeutic light) are reported following irradiation with non-laser sources and secondly, tissue scattering, as well as fiber optic delivery systems used in many experiments rapidly degrade coherency . . . Thus any effects produced by low-energy lasers may be due to the effects of light in general and not to the unique properties of lasers”. This view is not difficult to accept when it is remembered that wave-length dependent photobiochemical reactions occur throughout nature and are involved in such things as vision, photosynthesis, tanning and Vitamin D metabolism. In this view, laser therapy is really a form of light therapy, and lasers are important in that they are convenient sources of intense light at wavelengths that stimulate specific physiological functions (Lasers in Surgery and Medicine 9:1-5, Mayo Clinic, Rochester, Minnesota, 1989).
The equation between the machine and the biological response is a common error often made by those who wish to promote the commercial interests of low-energy laser technology. LEDs and LASERS are no more than convenient devices for producing electromagnetic radiation at specific wavelengths, and in addition to the one already cited, several other studies establish than it is the light itself at specific wavelengths that is therapeutic in nature and not the machine which produced it.
For example, Kendric C. Smith at the Department of Radiation Oncology, Stanford University School of Medicine, concludes in an important article entitled The Photobiological Effect of Low Level Laser Radiation Therapy (Laser Therapy, Vol. 3, No. 1, Jan - Mar 1991)
[2] that
1) Lasers are convenient machines that produce radiation.
2) It is the radiation that produces the photobiological and/or photophysical effects and therapeutic gains,
not the machines.
3) Radiation must be absorbed to produce a chemical or physical change, which results in a biological response. What are the Difference between LED’s and LASERS?
Light Emitting Diodes (LEDs) are another form of light therapy that is a relatively recent development of the laser industry. LEDs are similar to lasers inasmuch as they have the same healing effects but differ in the way that the light energy is delivered. A significant difference between lasers and LEDs is the power output. The peak power output of LEDs is measured in
milliwatts, while that of lasers is measured in watts. However, this difference when considered alone is misleading, since the most critical factor that determines the amount of energy delivered is the duty cycle of the device.
LED devices usually have a 50% duty cycle. That is, the LED pulse is "on" for 0.5 seconds and "off" for 0.5 seconds versus the 2 ten-millionths of a second burst from laser at 1 cycle per second (1 herz). Moreover, LED is "on" 50% of the time and "off" 50% of the time regardless of what frequency setting (pulses per second) is standard. In the majority of lasers now available to the professional and consumer markets, the energy output varies with the frequency setting: the lower the frequency, the lower the output.
LEDs do not deliver enough power to damage the tissue, but they do deliver enough energy to stimulate a response from the body to heal itself. With a low peak power output but high duty cycle, the LEDs provide a much gentler delivery of the same healing wavelengths of light as does the laser but at a substantially greater energy output. For this reason, LEDs do not have the same risk of accidental eye damage that lasers do.
Furthermore LEDs are neither coherent nor collimated and they generate a broader band of wavelengths than do the single-wavelength laser. Non-collimation and the wide-angle diffusion of the LED creates a greater ease of application, since light emissions are thereby able to penetrate a broader surface area. Moreover, the multiplicity of wavelengths in the LED, contrary to the single-wavelength laser, may enable it to affect a broader range of tissue types and produce a wider range of photochemical reactions in the tissue.
If LED disperses over a greater surface area, this results in a faster treatment time for a given area than laser.
Laser & LED Therapy - Best of both world
This
means that LEDs are indeed effective but lasers might be better simply due
to the lower power density of LEDs. With the use of both Lasers and LEDs
the Leimo is able to give users the best of both worlds - Red light
therapy with LEDs + low power laser therapy. We do encourage you to read some interesting arguments concerning LED vs. Lasers from this website :www.Laser.nu 
References :
1) Low-Energy Laser Therapy: Controversies & Research Findings, Jeffrey R. Basford MD; Mayo Clinic;
Lasers in Surgery and Medicine 9, pp. 1-5 (1989)
2.) The Photobiological Basis of Low Level Laser Radiation Therapy, Kendric C. Smith; Stanford University
School of Medicine; Laser Therapy, Vol. 3, No. 1, Jan - Mar 1991
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