A transcutaneous oxygen and carbon dioxide monitor is a device that measures the oxygen and carbon dioxide levels in a baby's blood. This test does not require a doctor or a nurse to take a blood sample from the baby.

The monitor is connected to the baby by a lead (wire), the end of which has a small circle that is held in place with a small round adhesive patch. The circle heats the skin, which allows it to measure blood oxygen and carbon dioxide content. The machine translates this information into a constant readout and has an alarm for readings that are above or below safe levels.