NeoSpHb Study: Can a Painless Device Detect Anaemia in Babies Without Blood Tests? A Study in the Neonatal Intensive Care Unit (NICU)

The goal of this study is to evaluate the diagnostic performance and feasibility of non-invasive spectrophotometric haemoglobin (SpHb) measurement for detecting anaemia in infants admitted to the Neonatal Intensive Care Unit (NICU). The main questions it aims to answer are: 1. What is the agreement between non-invasive SpHb and laboratory reference total haemoglobin (tHb)? 2. How accurately can non-invasive SpHb detect clinically significant laboratory anaemia (Hb \< 10g/dL)? 3. What is the feasibility (success rate and time-to-reading) and what physiological factors (e.g., perfusion index) moderate measurement accuracy in NICU infants? Researchers will compare non-invasive continuous SpHb readings against routine invasive laboratory haemoglobin values (tHb) obtained during standard clinical care from the same clinical encounter. Participants will: 1. Have a non-invasive optical sensor applied to an approved peripheral site (e.g., foot or palm) to record an SpHb reading whenever routine blood sampling is required by their attending clinician. 2. Undergo standard routine blood sampling (venous, arterial, or capillary) for laboratory haemoglobin testing as part of usual clinical care, with no extra blood drawn for research purposes.