| Popis: |
Traditionally, light for phototherapy and photodynamic therapy has been administered in a clinical environment using lasers or bulky lamp systems; however light-emitting diodes (LEDs) for phototherapy and photodynamic therapy are gaining in popularity due to their high efficiencies, low-cost designs, and design versatility. In addition, LEDs can be assembled into flexible bandages to be worn on the patient’s skin to replace traditional lamp systems and increase patient comfort. However, because this brings the LEDs closer to the skin, light intensity hot spots form which is not desirable for phototherapy where uniform irradiance is required to inactivate target cells most effectively. We present an optical simulation of a blue LED array to evaluate the effects of immersion media of varying thickness on the uniformity of light distribution for near-field illumination in phototherapeutic applications. We have compared different immersion materials (air, water, and optical-grade silicone) placed in between the LED array and the skin with the goal of uniform irradiance distribution and optimized lighting efficiency. The irradiance incident on the tissue over an area of 60 cm2 was simulated and compared for the three materials. Both silicone and water showed an increase in uniformity over an area of 14.4 cm2 as the thickness increased without a significant decrease in irradiance at the tissue. These results show promise for future flexible photonic devices where a high degree of uniformity is required in situations where the device needs to be placed on or near the skin. |
