Fig. 3.

The recorded $P_{{\text{O}}_2}$ amplitude, expressed as a fraction of the actual value (recorded $\Delta P_{{\text{O}}_2}/\text{actual}\text{imposed}$$\Delta P_{{\text{O}}_2}$), in flowing blood at 39 °C is plotted against the simulated respiratory rate. The black and grey circles show data recorded by the PMMA and AL300 sensors respectively (average ± SD; oscillations n = 10). The duty cycle was fixed at 50%, simulating an I:E of 1:1. Panel A shows data recorded 20 min after the sensors were immersed in flowing blood, and panel B shows data recorded 5 h after continuous immersion.