Development of an Ultraviolet A1 Light Emitting Diode-based Device for Phototherapy

Abstract

We developed a novel phototherapy device based on an ultraviolet light emitting diode (UV LED) with a peak wavelength of 365 nm and the full width at half maximum of 10 nm. The equipment comprised a 16 x 16 (50 cm x 50 cm) UV LED matrix. The system was designed to irradiate only the diseased part of the skin. To evaluate the characteristics of this device, we compared consumed power, irradiation intensity, uniformity of the irradiation intensity, rise time and stability of the irradiation intensity, and in vivo irradiation of mice between a conventional UVA1 (340-400 nm) phototherapy device and the UV LED device. The UVA1 LED device exhibited more desirable characteristics than the UVA1 lamp device, i.e., fewer thermal effects on in vitro and in vivo systems. Furthermore, to evaluate the efficacy of both light sources, cultured T cells were irradiated and the induction of apoptosis was analyzed. Both light sources efficiently induced apoptosis.

Light-emitting diodes in dermatology: stimulation of wound healing

“…Opracowano również urządzenie do fototerapii na bazie diod LED emitujące promienio-wanie UV o długości fali 365 nm. Opiera się ono na pojedynczym czipie GaN UV LED [30]. Czas działania tego urządzenia jest trzy razy dłuższy niż tradycyjnych ultrafioletowych lamp fluorescencyjnych.…”

Ultraviolet Radiation in Wound Care: Sterilization and Stimulation

“…A device based on light emitting diode (LED) emitting UV radiation (wavelength 365 nm, full width half maximum 7 nm, output power 250 mW) was developed by Inada et al 93 This is a type of single-chip GaN-based UV LED, which is relatively small (350 lm · 350 lm). This UV LED can be operated with a dry battery and can be used to irradiate only the diseased skin.…”