A computational simulation of reflector and tube effects in ultraviolet phototherapy

While ultraviolet phototherapy is effective at treating a wide range of skin conditions, over exposure to ultraviolet radiation has a number of detrimental effects including but not limited to erythema, ocular damage and even oncogenesis. It is therefore important to quantify and control the dose received in order to maximize the effectiveness of treatment while minimizing the potentially damaging side effects. Recent dose models have been developed for this purpose, incorporating both the irradiance from the phototherapy lamps and the contributions from metallic reflectors. These models have good predictive power, but the situation is complicated by the huge variety of cabin and mirror geometries available. This work simulates a variety of possible treatment configurations to examine the implications these factors have on dose homogeneity and global irradiance, and shows that the relationship between global irradiance and number of tubes is complex and nonlinear. This has implications for both cabin design and treatment planning.