Feasibility of Camera-Based Continuous Bilirubin Level Monitoring for Neonates

This study explores the feasibility of using an RGB camera to estimate the bilirubin level of neonates with an emphasis on applications within the Neonatal Intensive Care Unit (NICU), aiming to provide a non-contact, real-time, and continuous monitoring solution for neonatal jaundice. We investigated two fundamental models for camera-based bilirubin level monitoring: blood perfusion (AC component) based and skin reflectance (DC component) based. The blood perfusion model used the ratio of AC components in the blue and green channels, while the skin reflectance model employed the ratio of DC components in these two channels. Videos of 68 neonates in the NICU were recorded using an RGB camera and custom-built dual-wavelength light sources (460 nm and 570 nm). Clinical results showed that the blood perfusion based method negatively correlated with bilirubin concentration, contrary to our modeling and expectation, likely due to the interference of concentration in arterial blood. In contrast, the skin reflectance model demonstrated an expected strong negative correlation between DC ratio and bilirubin (i.e., r=-0.652 and p <0.005) and better consistency with the reference of transcutaneous bilirubin meter (agreement limits range = -5.72 mg/dL to 4.06 mg/dL) in intermittent bilirubin level estimation experiments. Additionally, camera-based continuous bilirubin level monitoring of resting neonates shows high potential (MAE = 4.57 mg/dL) in the NICU.