A Novel Phototherapy Device

Phototherapy is the standard treatment for severe cases of hyperbilirubinemia in newborns. Phototherapy exposes the infants to light in the range of 400-500 nm to isomerize unconjugated bilirubin in the skin. Any light source that produces this wavelength can be used, including the sun (though there is a risk of sunburn), fluorescent or halogen lamps, or, more recently, light-emitting diodes. Despite the well-established efficacy of phototherapy devices and their relative simplicity-being not much more than a floor lamp-phototherapy devices are too expensive for developing world hospitals to purchase, with typical hospital models ranging from US$3,000 to US$5,000. In addition, the resource-poor setting presents a more challenging engineering problem than most. Phototherapy devices are frequently donated to developing world hospitals. However, donated phototherapy devices typically run for no more than a few months once donated and, even then, offer little value to some hospitals. Given this background, we set out to design a phototherapy device specifically for use in the developing world. As a minimum, we knew that it had to have a light source with an extraordinarily long life span and have battery backup so that it could run during frequent power outages. Our design uses LEDs and is powered by a car or motorcycle battery. In this article, we present the full engineering design cycle, staring with needs identification and continuing through several cycles of engineering field trials and results with comments on the differences between the engineering design cycle executed in, and for, the developing world.