Wearable Sensor Monitors Newborn’s Bilirubin Levels

A new study describes a neonatal colorimetry-based device that provides real-time detection of jaundice and simultaneous sensing of vital signs.

Developed at Yokohama National University (YNU; Japan) and the National Institute of Health Sciences (NIHS; Kawasaki, Japan), the wearable transcutaneous bilirubinometer is composed of a flexible polydimethylsiloxane (PDMS) three-dimensional (3D) printed lens formed over light emitting diodes (LEDs) and oxygen saturation (SpO2) and heart rate (HR) photo detectors. The lens, integrated circuits to control and process tasks, and a coin cell battery supply are held in a blackened PDMS and Ecoflex structure. The sensing part of the device contacts the neonate’s forehead.


In clinical experiments on 50 babies, the device demonstrated the possibility of simultaneous detection of bilirubin, SpO2, and HR, and could consistently measure bilirubin during phototherapy; however, the device was not accurate enough to suffice for clinical decision-making. According to the researchers, the results show the potential of a future combined-treatment approach that automaticly links between the wearable bilirubinometer and a phototherapy device for optimization of neonatal jaundice treatment. The study was published on March 3, 2021, in Science Advances.

“We have developed the world's first wearable multi-vital device for newborns that can simultaneously measure neonatal jaundice, blood oxygen saturation, and pulse rate,” said senior author Hiroki Ota, PhD, of the YNU Department of Mechanical Engineering, and colleagues. “The real-time monitoring of jaundice is critical for neonatal care. Continuous measurements of bilirubin levels may contribute to the improvement of quality of phototherapy and patient outcome.”

Neonatal jaundice is a physiological phenomenon caused by hemoglobin in the prenatal fetus which is rapidly broken down into bilirubin after birth. As metabolic capacity of the neonate liver is immature, it cannot process large amounts of bilirubin, leading to hyperbilirubinemia; excess bilirubin is deposited in the skin, turning it yellowish. Hyperbilirubinemia can also cause deposition in the basal ganglia, resulting in neurologic dysfunctions such as mental retardation, athetotic cerebral palsy, sensorineural deafness, and upper gaze paralysis. To combat the jaundice, blue light phototherapy is administered, transforming the bilirubin into a hydrosoluble photoisomer that can be easily excreted in urine.

Related Links:
Yokohama National University
National Institute of Health Sciences