Fig. 7.

In a), a smoothed histogram of oxygenation in vessels and in the surrounding tissue for a healthy subject S30 is shown. Integral of the histogram ( $1000$ bins) is normalized to unity. In b), a scatter plot of most frequent values of histograms (mode) for the whole population of both vessel and surrounding tissue oxygenation is displayed. Each node, marked with the sequential number of the subject in the study represents a single animal. With a maroon line, value of $Sp{O}_2=0.35$ is denoted. Where groups of subjects are not obvious from label placement, additional colored line above the number indicates the appropriate group.