The HeartLight system is a wireless optical sensor within a custom newborn hat to allow quick and accurate HR monitoring. It will be compared to ECG, PO and electronic stethoscope to determine the accuracy and reliability. The trial has 4 phases; Phase 1 evaluates the thermal properties of the hat, Phase 2 evaluates the accuracy and reliability of the HeartLight sensor on babies within the Neonatal Intensive Care Unit environment, Phase 3 evaluates the HeartLight sensor in newborn babies born by cesarean section and Phase 4 evaluates the performance of the HeartLight sensor in babies of all gestations requiring resuscitation and stabilisation at birth.