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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.

The automated physiologic profile provides the critical care physician with hemodynamic, oxygen consumption and tissue utilization data at reasonable cost. A paramedical assistant performs all data acquisition, recordings and blood sampling procedures. Data reduction is performed through use of off-the-shelf desk-top calculator equipment and accessories and a standardized graphic display is provided for the physician in charge. The physiologic profile has been utilized in high-risk patients requiring medical and surgical interventions. It is routinely employed in postoperative monitoring of cardiac patients and patients undergoing major surgical procedures with associated cardiovascular decompensation. Diagnosis of cardiac and pulmonary deterioration and promptness of advanced support interventions represent additional areas of effective clinical application.

An instrument has been developed to record contrast dilution curves by a noninvasive technique. Transthoracic roentgen density alterations are recorded by use of a solid state radiation detector array. A small amount of injected nonradioactive, radiopaque contrast material is distrubuted throughout the central circulation. The detector array positioned over the cardiopulmonary silhouette, records changes in density during the passage of the contrast material, and typical indicator dilution curves are transcribed. These curves reflect changes in blood flow distribution, vascular volume, cardiac function, and intrathoracic vascular shunts; and define the hemodynamic status of the circulatory system.