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(a)

(b)

Figure 1: (a) Clinical evaluation of absolute lactate levels from subcutaneous adipose tissue (satLAC) on the $y$-axis versus reference measurements from arterial blood (artLAC) on the $x$-axis. Clinical lactate grid as described in the method section is indicated as hatched areas. (b) 6-hour lactate trend analysis with respective clinically acceptable and unacceptable ranges as described in the method section. Relative 6-hour lactate trend of reference arterial blood lactate readings ($\mathrm{\Delta }$ artLAC) and calibrated subcutaneous lactate readings ($\mathrm{\Delta }$ satLAC) are indicated on $x$-axis and $y$-axis, respectively. Upper and lower thick lines represent limits for acceptable lactate trend identification from subcutaneous adipose tissue measurements. Vertical-hatched lines indicate thresholds for decreasing and increasing reference lactate concentrations.