Design and preliminary validation of a personalized blue-light phototherapy device with adaptive neonatal posture and jaundice-guided irradiance regulation

Conventional blue-light phototherapy for neonatal pathological jaundice is usually delivered at fixed irradiance and under relatively passive body positioning, which may not reflect the dynamic change in bilirubin burden or the variation in effective light-exposed skin area during treatment. In clinical practice, neonatal posture directly affects illuminated body surface area, local pressure distribution, and overall phototherapy efficiency. To address these limitations, we developed a personalized blue-light phototherapy device integrating a blue-light irradiation module, a jaundice detection module, a posture-adaptive support module, and a control module for real-time regulation of both body position and light delivery. The proposed system was designed to optimize neonatal phototherapy from a biomechanics-engineering perspective by adjusting body posture to increase effective exposure area and reduce localized pressure, while simultaneously modulating blue-light irradiance according to real-time jaundice measurements. This study aimed to preliminarily evaluate whether the device could maintain therapeutic effectiveness while reducing cumulative irradiation and improving exposure efficiency. Twelve male Sprague-Dawley rats were randomly assigned to a blank control group, a model control group, a conventional phototherapy group, and a personalized device group. Except for the blank control group, jaundice was induced in all animals. During a 10-h intervention, the conventional group received fixed-intensity blue-light exposure, whereas the personalized device group received individualized irradiation adjusted according to real-time jaundice measurements under posture-stabilized exposure conditions. Total bilirubin (T-BIL), direct bilirubin (D-BIL), indirect bilirubin (I-BIL), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were assessed. Compared with the model group, both phototherapy groups showed significant reductions in bilirubin-related indices, especially I-BIL, indicating effective bilirubin clearance. No significant difference was observed between the personalized device group and the conventional phototherapy group in the major post-treatment biochemical outcomes. However, cumulative irradiation in the personalized group was significantly lower during the later treatment stages. These findings suggest that the proposed device can achieve therapeutic effects comparable to those of conventional phototherapy while reducing unnecessary blue-light exposure. The integration of posture-adaptive support and jaundice-guided light regulation may provide a feasible engineering strategy for individualized and potentially safer neonatal phototherapy.