Artificial Circulatory Setup.

<p>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) P_O2 analysis (ABL 700).</p

Influence of temperature and blood flow on MFPF P_O2 measurements: Linear regression model.

<p>Linear regression model: magnitude of P_O2 measurements, temperature and blood flow as independent variables, differences of P_O2 measurements as dependent variable. P_O2  =  oxygen partial pressure; MFPF  =  Multi Frequency Phase Fluorimetry; CTE  =  Clark-type electrode; CI  =  confidence interval.</p

Multi Frequency Phase Fluorimetry/FOXY-AL300 Probe Response Time.

<p>Example of an MFPF step-down manoeuvre in artificial circulatory setup (human blood-phase). The graph displays the absolute MFPF P_O2 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.</p

Multi Frequency Phase Fluorimetry P_O2 vs. Clark-type Electrode P_O2 (human blood <i>ex vivo</i>, normobaric range).

<p>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 P_O2 values. The dashed line represents the bias, the solid lines the 1.96 standard deviation interval.</p

Multi Frequency Phase Fluorimetry P_O2 vs. Clark-type Electrode P_O2 (porcine blood <i>in vitro</i>, normobaric range).

<p>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 P_O2 values. The dashed line represents the bias, the solid lines the 1.96 standard deviation interval.</p