Dilution curves (%, thin lines) for individuals. A non-linear equation is, after iteration, fitted to the data generating a mean dilution curve (thick line) from which parameter estimates for distribution (V
) and clearance (Cl) can be calculated . The initial dilution effect of the infused bolus is approximately 25% (0.25 on the y-axis) but the effect is transient. The fluid is almost completely eliminated from the central space after 2 hours. The y-axis is the percentage dilution and the x-axis is time in minutes. In these individuals, infusion times were 10 minutes and the experiment lasted for 120 minutes.