We examined the accuracy with which left ventricular output can be estimated by equilibrium radionuclide ventriculography. After red blood cells were labeled in vivo, we measured left ventricular end-diastolic and end-systolic count rates and the count rate in 5 ml of the patient's blood. After estimating the average ratio of counting efficiency for the left ventricle to counting efficiency for...

The dye T-1824 (Evans Blue) has gained wide acceptance for determining plasma volume. Recently there has been a renewed interest in dye circulation studies for the measurement of cardiac output, central volume, cardiac shunts, and valvular regurgitation. The method of estimation most commonly used is spectrophotometric analysis of the dye-tinged plasma (or serum) compared with standard dye solu...

Clinical diagnoses depend on a variety of physiological variables but the full range of these variables is seldom known. With the load placed on the human body during competitive rowing, the physiological range for several variables is illustrated. The extreme work produced during rowing is explained by the seated position and the associated ability to increase venous return and, thus, cardiac ...

The accuracy of the thermal dilution technique for measuring cardiac output in infants and children has been assessed by comparison with the direct Fick technique. Satisfactory correlation between the two methods has been demonstrated, and it is concluded that a commercially available monitor can be used to determine cardiac output by thermal dilution in acutely sick infants and children. The v...

The objective of this study is to design a robust direct model reference adaptive controller (DMRAC) for a nonlinear cardiovascular model over a range of plant parameters representing a variety of physical conditions. The direct adaptive controllers used in thisd study require the plant to be almost strictly positive real (ASPR) that is, for a plant to be controlled there must exist a feedback ...