Premature babies typically spend days, weeks, or longer in a neonatal intensive care unit (NICU). They have a myriad of needs, including some that may be in conflict. In addition to providing nutrition and warmth, NICU clinical staff closely monitor vital signs plus the specific needs of individual babies. Wearable biometric sensing devices may handle certain monitoring chores, but elaborate hookups and wires can make it harder for attendants and volunteers to pick up and hold newborns. In those instances, the child is more likely to miss out on early contact bonding.

A team of scientists and engineers from Northwestern University working with physicians from Prentice Women’s Hospital and the Ann & Robert H. Lurie Children’s Hospital in Chicago developed a new form of soft, flexible wireless body sensors to help preemies get more cuddling and hugs. The vital sign sensors use water to stick to the skin and wireless near-field communications (NFC) to transmit significant data. The sensor uses an on-board processor, which minimizes the amount of transmitted information and enables NFC. According to the NWU team, eliminating hard-wire contact with delicate neonatal skin lessens injury risk as well as removing a physical barrier to skin-to-skin parental or caregiver contact. In a study published in Science, the development team used a pair of soft sensors: one on the chest to capture ECGs and the other on the base of the foot to record photoplethysmograms (PPGs). Working in concert, the sensors continuously transmitted ECG, PPG, and skin temperature data. The team extrapolated heart rate, heart rate variability, respiration rate, blood oxygenation, and pulse arrival time (a surrogate for systolic blood pressure) from the data. The study demonstrated that in testing with 28-week to full term neonates, the results were comparable to the newest clinical-standard systems.

Following the successful feasibility testing, the Northwestern-led project continues with additional clinical studies to validate data and extend the test sample to additional age groups and ethnicities. Remaining challenges include nursing staff acceptance, compatibility with legacy monitoring systems, and device sterilization for reuse. Other potential applications include use with burn victims and patients with certain skin diseases.