Figure 3. Discrete saturation transform: A plot of adaptive correlation canceler energy output versus possible SpO²values. Two peaks occur in the energy output. The right-hand peak (r^a= 97%) corresponds to the arterial saturation and yields the displayed SpO²value. The left-hand peak (r^v= 80%) may correspond to the saturation of the venous blood, although this has not been confirmed experimentally. (Data provided courtesy of Masimo.)