Valerie Y. Chock, Zachary A. Vesoulis
The use of light-based assessment for brain monitoring in the medical field has evolved significantly, particularly with the adoption of near-infrared spectroscopy (NIRS). Initially utilizing visible light, advancements shifted to the near-infrared spectrum (700–1,000 nm), improving the detection of changes in hemoglobin and cytochrome oxidation states. NIRS offers a noninvasive, bedside monitoring solution that provides continuous measurements, akin to pulse oximetry, making it invaluable in neonatal intensive care units (NICUs) for infants at high risk of neurological injury. With FDA approval for use in neonates, NIRS devices are tailored for infants, even those weighing less than 2.5 kg. This chapter emphasizes the importance of clinicians understanding NIRS’ functional basis, clinical applications, and limitations. As NIRS monitoring expands into neonatal care, an evidence-based approach is critical to optimize its benefits while addressing potential shortcomings in clinical practice for vulnerable populations.