There is a machine that is FDA approved that can measure how much oxygen is delivered to the brain. This non-invasive (outside the body) machine uses Near-infrared spectroscopy (NIRS), which is similar technology used in pulse oximetry and is routinely used to measure the level of oxygen in blood. At Children's Healthcare of Atlanta, we typically place the NIRS machine on the baby in the Cardiac Intensive Care Unit immediately after their first surgery to monitor oxygen delivery to the brain. The monitor has proven to be accurate in this situation.