A sensor system, for use in a phototherapy system for treatment of neonatal jaundice, designed to harvest energy from the phototherapy system. The sensor system is wirelessly connected to the phototherapy system and provides measurements of the total serum bilirubin levels of the infant. The continuous measurement of the total serum bilirubin allows the phototherapy system to personalize the treatment of each infant, minimizing any unwanted side effects of the phototherapy. The energy harvesting performed by the sensor removes the need to manually replace or recharge batteries, which may disturb the infant during treatment, and may enable the sensor system to operate without an energy storage device, such as a battery, altogether.
