A fully automated cardiac output analysis system

An automatic cardiac output analysis system is described in which indicator dilution studies are performed serially without operator assistance. Indicator dye injection, blood sampling, and monitoring for air entry into the system are performed automatically through a present program sequence. Sampled blood is returned to the subject through a venous cannula resulting in an absence of blood loss. This system may be used in performing cardiac output analyses on a serial basis and in infants and small animals where blood loss is critical.