Heat map of mean arterial pressure error and stroke volume index in all cases by group. A total of 34,000 data points are represented in the figure (three observations of mean arterial pressure/stroke volume index per minute per patient). The density of color in a location indicates the relative proportion of error for that combination of stroke volume index and mean arterial pressure error. The computer-assisted group error is visually clustered much more tightly than the manually adjusted goal-directed therapy group error around 0. Additionally, this figure illustrates higher stroke volume indexes in the computer-assisted group.