Figure 1.
Artificial circulatory setup with two independent circuits filled with human packed red blood cells (haematocrit of 30%). A switching valve between the circuits enabled a step-change between highly oxygenated (circuit 1: purged with pure oxygen) and oxygen free blood (circuit 2: purged with nitrogen). Black arrows represent direction of blood flow. Adapting the settings of the rollerpumps and the heating-cooling device (heat exchanger) allowed blood-flow and temperature to be controlled. Via the O2/N2 blenders, oxygen content could be adapted at fixed sweep gas flow over the oxygenators. Measurement chamber contained 1.) ports for insertion of MFPF probes (Foxy-AL 300); 2.) a temperature probe and 3.) a sampling port for Clark-typed based (CTE) PO2 analysis (ABL 700).
Figure 2.
Multi Frequency Phase Fluorimetry PO2 vs. Clark-type Electrode PO2 (porcine blood in vitro, normobaric range).
Panel A: Linear regression plot, the solid line displays the line of best fit, the dashed line shows the line of identity; Panel B: Bland-Altman plot showing the differences (CTE-MFPF) versus the means for absolute PO2 values. The dashed line represents the bias, the solid lines the 1.96 standard deviation interval.
Figure 3.
Multi Frequency Phase Fluorimetry PO2 vs. Clark-type Electrode PO2 (human blood ex vivo, normobaric range).
Panel A: Linear regression plot, the solid line displays the line of best fit, the dashed line shows the line of identity; Panel B: Bland-Altman plot showing the differences (CTE-MFPF) versus the means for absolute PO2 values. The dashed line represents the bias, the solid lines the 1.96 standard deviation interval.
Figure 4.
Multi Frequency Phase Fluorimetry PO2 vs. Clark-type Electrode PO2 (human blood ex vivo, hypoxic and normoxic range).
Panel A: Linear regression plot, the solid line displays the line of best fit, the dashed line shows the line of identity; Panel B: Bland-Altman plot showing the differences (CTE-MFPF) versus the means for absolute PO2 values. The dashed line represents the bias, the solid lines the 1.96 standard deviation interval.
Table 1.
Influence of temperature and blood flow on MFPF PO2 measurements.
Table 2.
Influence of temperature and blood flow on MFPF PO2 measurements: Linear regression model.
Figure 5.
Multi Frequency Phase Fluorimetry/FOXY-AL300 Probe Response Time.
Example of an MFPF step-down manoeuvre in artificial circulatory setup (human blood-phase). The graph displays the absolute MFPF PO2 values over the time course. The arrow marks the time when the switching valve was changed between the oxygenated (750 mmHg) and non-oxygenated blood (0 mmHg) circuit.