Blood Irradiation: Laser vs LED


Some people wonder about the effectiveness of low level laser therapy over a regular light emitting diode (LED) therapy with regard to intranasal blood irradiation.

Several scientific publications suggest that low level lasers can be more effective than LEDs. A number of websites publish these type of findings to provide validation for their products. Such studies are based on transcutaneous or transdermal applications i.e. applied to skin, but not on intravenous or intranasal blood irradiation the latter being our case.

Cells and body systems respond to a combination of the wavelength of light and an energy dosage. The coherent light in lasers can have more concentrated energy than the regular non-coherent light in LEDs, however most commercially available semi-conductor low level laser diodes have a built-in divergence of around 57 degrees. So low level lasers are more effective for therapeutic purposes than LED given their different coherency values.

Professor Kendric Smith of the Stanford University School of Medicine, a respected scientist in photobiology, has this to say, "All too often the laser phototherapy literature is written as if a laser is magical. Lasers .. emitted radiation follows(except for coherence) all of the same laws of physics and chemistry that the same wavelength of radiation from a conventional (non-coherent) light source follows. [1]

Another leading scientist in the field of low level laser therapy, Tiina Karu says, "No significant difference was found for growth stimulation regardless of whether the light used was generated by a laser or from light of the same wavelength from a filtered incandescent lamp. [2]

In a landmark NASA-sponsored study that was published in 2001, scientists have found that LED therapy was more effective for faster wound healing and significantly increased pain reduction. [3]

When using LEDs instead of laser diodes, we compensate for the loss of coherency by increasing the energy dosage per area so as a result we would be achieving the same level of effectiveness as in the case of low level laser application.

Because low level laser devices use well under 10 mW in energy output and we deal with less thinner dermal layers, the increase is so small that the user would not physically feel the difference. The membrane inside the nasal cavity is thin enough for a LED diode with some recalibration to achieve the same result as a laser diode.

In other words our LED device e.g. Qi-Light has the same effectiveness outcomes as the laser device, RadiantLife LT, yet the LED device is a bigger drain on the battery by about 30% because of the additional energy requirements.

  1. Smith, K.C. (2005), Laser (and LED) Therapy Is Phototherapy, Phtotomedicine and Laser Surgery, 23, 78-80.
  2. Karu, T. (1989). Photobiology of low-power laser effects. Health Physics, 56, 691-704.
  3. Whelan, H.T. et al (2001). Effect of NASA Light-Emitting Diode Irradiation on Wound Healing. Journal of Clinical Laser Medicine & Surgery. 19 (6).