Bi-modal system-on-chip platform for bilirubin monitoring by using photometric and temporal degradation approaches

Hyperbilirubinemia in infants and cirrhosis in adults remain major global causes of sickness and death, predominantly for people living in areas with poor or limited healthcare resources. Clinically, the two conditions require measuring levels of bilirubin in blood for diagnostic and prognostic purposes. While the existing techniques provide the most comprehensive pathology-lab results, they suffer from complexity and size requirements, and measurements are impractical for point-of-Care (PoC) testing. Furthermore, the existing transcutaneous devices (for neonates) are pricey, preventing the possibility of dissemination for home health care applications. This study uses an integrated and all-inclusive miniature (3.5 × 7.0 mm) system-on-chip platform (MAX86916) to measure bilirubin concentration. On MAX86916 embeds two optical sources (blue LED and green LED) which are utilized for dual-wavelength (DWL) measurement. Furthermore, a new photodegradation kinetics approach was incorporated with DWL approach to enhance the overall system reliability and accuracy. Bilirubin concentration was extracted by monitoring the optical transmission and the photodegradation responses. Measurements were carried out on porcine blood, the best existing surrogate for human blood, and the concentration of bilirubin was maintained within the range of pathophysiological levels (1 mg/dL to 50 mg/dL). The measurement could require a volume of less than 10 µL of a blood sample. Our findings show a good system accuracy of ∼ ±10 % and lay the groundwork for PoC bilirubin monitoring, primarily for hyperbilirubinemia and cirrhosis out of clinics and hospitals.