Wavelength & Output Power
Near infrared light can penetrate 3-4 cm beyond the skin to deep tissue. It can increase tissue temperature 3°C, tissue perfusion 8 times, and tissue oxygen partial pressure 30%
The therapeutic effectiveness of near infrared light (NIR) has been determinate for decades1-6. Genesis pain relief light use NIR as main light resource produced in special radiators whose whole incoherent broad-band radiation of a full spectrum light is passed through a cuvette, containing water-like fluid7. The spectrum of filtered light emphasises visible light and infrared-A which is called near infrared light (400-1400 nm) and eliminates ultraviolet and infrared-B and C which causes the majority heat over the skin (Figure1). The Genesis light leads to high penetration properties (3-4 cm) with a low heat load to the surface of the skin8.
Figure 1. The spectrum of Genesis pain relief light is from 400 to 1400 nm. The total output power is 4.9 W in high and 2.3 W in low scale. The Power Intensity is 339 mW/cm2 in high and 161 mW/cm2 in low scale. The therapeutic windows of skin (600-700nm), connective tissue (700-800nm), muscle and spinal cord (750-850nm), blood (800-900nm) and nerve (900-1100nm) are all included into this spectrum*. The therapeutic window defines the range of wavelengths where light has its maximum depth of penetration in tissue.
*Kimberly R. Byrnes, Ronald W. Waynant, Ilko K. Ilev, Xingjia Wu, Lauren Barna, Kimberly Smith, Reed Heckert, Heather Gerst, and Juanita J. Anders. Light Promotes Regeneration and Functional Recovery and Alters the Immune Response after Spinal Cord Injury. Lasers in Surgery and Medicine 36:171-185 (2005)
Light Physics department of McMaster University measured Genesis light spectroscopy and describe the light characteristics as visible light plus near infrared. The total light power intensity is at 339 mW/cm2 (Table 1) and the output power at 4.9 W in high scale. Figure 2-4 show the light intensity distribution in different wavelength interval.
| Wavelength | Power (W) | Total Power(W) | ||||
| 400-600nm | 600-700nm | 700-900nm | 900-1100nm | >1100nm | ||
| Low scale | 0.0 | 0.3 | 0.7 | 0.7 | 0.7 | 2.3 |
| High scale | 0.1 | 0.6 | 1.3 | 1.5 | 1.4 | 4.9 |
| Wavelength | Power Intensity (mW/cm2) | Total Power Intensity (mW/cm2) | ||||
| 400-600nm | 600-700nm | 700-900nm | 900-1100nm | >1100nm | ||
| Low scale | 1.8 | 17.9 | 46.6 | 47.0 | 47.8 | 161.2 |
| High scale | 8.3 | 43.0 | 89.1 | 103.9 | 94.7 | 339.0 |
Table 1. Output Power and Power Intensity of Genesis Light in total and various wavelength interval including 400-600nm, 600-700nm, 700-900nm, 900-1100nm and >1100nm.
Figure 2. 600-700 nm Power intensity distribution across a 100 x 100 mm planar region.
Figure 3. 700-900nm Power intensity distribution across a 100 x 100 mm planar region.
Figure 4. 900-1100nm Power intensity distribution across a 100 x 100 mm planar region.
NIR is well accepted therapeutic tools in the treatment of infected, ischemic, and hypoxic wounds, along with other soft tissue injuries9. Positive effects include acceleration of wound healing, improvedrecovery from ischemic injury and pain relief. NIR produces a therapeutically usable field of heat in the tissue and increases tissue temperature, oxygen partial pressure and tissue perfusion. These three factors are vital for a sufficient tissue supply with energy and oxygen. As inflammation and wound is the main pathology procedure in the above disorders, the defences of them all depend decisively on a sufficient supply with energy and oxygen10.
Abstracts
- Light promotes regeneration and functional recovery and alters the immune response after spinal cord injury
- Photodynamic therapy (PDT) and waterfiltered infrared A (wIRA) in patients with recalcitrant common hand and foot warts
- Water-filtered infrared-A (wIRA) can act as a penetration enhancer for topically applied substances
Reference
1. Low-Intensity Light Therapy: Exploring the Role of Redox Mechanisms. Tafur, Joseph. 4, s.l. : Photomedicine and laser surgery , 2008 , Vol. 26. 17-21.
2. Role of reactive oxygen species in low level light therapy. Huang, Ying-ying, Arany, Praveen R. and Hamblin, Michael R. s.l. : Mechanisms for Low-light Therapy , 2009, Vol. 7165. 2-11.
3. The effects of laser radiation on wound healing and collagen synthesis. Mester, E., and Jaszsagi-Nargy, E. s.l. : Studia Biophys, 1973, Vol. 35. 227-230.
4. Effects of visible and near-infrared lasers on cell culture. Lubart, R., Wollman, Y., Friedman, H., et al. s.l. : J. Photochem. Photobiol., 1992, Vol. 12. 305-310.
5. Photobiomodulation directly benefits primary neurons functionally inactivated by toxins. Wong-Riley, M.M.T., Liang, H.L., Eells, J.T., et al. s.l. : J. Biol. Chem., 2005, Vol. 280. 4761-4771.
6. Primary and secondary mechanisms of action of visibile to near-IR radiation on cells. Karu, T. s.l. : J. Photochem. Photobiol.Biol., 1999, Vol. 49. 1-17.
7. Principles and working mechanisms of water-filtered infrared-A (wIRA) in relation to wound healing [review]. G., Hoffmann. 2, s.l. : GMS, 2007, Vol. 2. 54-64.
8. Water-filtered infrared-A (wIRA) can act as a penetration enhancer for topically applied substances. Nina Otberg, Diego Grone, Lars Meyer, Sabine Schanzer, Gerd Hoffmann. s.l. : GMS, 2008, Vol. 6. 1612-1626.
9. Randomized clinical trial of the influence of local water-filtered infrared A irradiation on wound healing after abdominal surgery. Hartel M, Hoffmann G, Wente MN, Martignoni ME, Buchler MW, Friess H. s.l. : British Journal of Surgery, 2006, Vol. 93. 952-960.
10. Water-filtered infrared-A (wIRA) in acute and chronic wounds. Hoffmann, Gerd. 2, s.l. : German Medical Sciences, 2009, Vol. 4. 1863-1893.