Noninvasive Continuous BP Monitoring in Newborns Based on Pulsatile Signal Morphological Features Using NIRS

The goal of this study is to evaluate if a novel near-infrared spectroscopy (NIRS) device can accurately estimate blood pressure in newborns at risk for unstable blood pressure. The main questions it aims to answer are: * Can NIRS accurately estimate blood pressure when compared to the gold standard, arterial line blood pressure * Can NIRS accurately estimate blood pressure when compared to infants with cuff blood pressure monitoring Researchers will compare NIRS-based estimates to arterial line blood pressure readings and manual cuff measurements to optimize and validate the FlexNIRS device for neonates to accurately estimate blood pressure continuously and noninvasively. Participants will wear a small, noninvasive NIRS sensor on the forehead.