Korean J Dermatol.  2011 Feb;49(2):125-130.

The Measurement of Optimal Power Distance in LEDs

• Park MK
• Kim BJ
• Kim MN
• Mun SK
• Hong HK
• Choi YS
• Jo YC

Abstract

BACKGROUND
The use of light technology in dermatology has grown rapidly over the last decade, with many developments in its use for the treatment of a wide variety of skin conditions from non-melanoma skin cancers to facial resurfacing for photo-damaged skin. Light-emitting diodes (LEDs) have attracted much attention in medical fields.
OBJECTIVE
(1) To assess the optimal distance of 630 nm LEDs (OmniLux(R), (Phototherapeutics Ltd, the UK)) and 830 nm LEDs (Healite(R) (Lutronic, Korea)) for maximum power as determined by a power meter and (2) to apply theory to practical use.
METHODS
Two separate hinged planar light emitting diode arrays were studied: 1) the Omnilux Revive(TM) (Phototherapeutics Ltd, the UK), which delivers non-coherent red light at a wavelength of 633+/-3 nm and 2) the Lutronic Healite (Korea), which delivers non-coherent light at a wavelength of 830+/-5 nm. An X93 power meter (Gigahertz-Optik, Germany) was placed against a black background in order to reduce the amount of reflected light. We measured the LED powers over a range of 3~25 cm in 1 cm increments.
RESULTS
On the irradiation side of the LED, power increases according to the mass effect of the radiation angle. However, at a certain distance, the power decline effect predominated over the amassment effect. In this respect, the LED light was estimated to be emitted in a reverse V shape. The proper irradiation distance for use in medical fields can thus be determined.
CONCLUSION
The proper irradiation distance of LED will be useful and the proper use of LED under the subjects' shape will be done in many medical fields.

Keyword

Healite; Irradiation distance; Light-emitting diodes (LED); Omnilux

MeSH Terms

Dermatology
Enzyme Multiplied Immunoassay Technique
Light
Skin
Skin Neoplasms