Fig. 1.

Synchronous amplitude-stable $P_{{\text{O}}_2}$ oscillations (5–50 kPa [37–375 mmHg]), recorded approximately 20 min after the sensors were immersed in flowing blood at 39 °C, are plotted against time (sensor up-date sampling rate: 10 Hz). The black and grey lines show data recorded by the PMMA and AL300 sensors respectively. The duty cycle was fixed at 50% to simulate an I:E ratio of 1:1. RR denotes respiratory rate. The PMMA sensor is seen to detect faithfully the entire $P_{{\text{O}}_2}$ oscillation amplitude at each RR, whereas the AL300 sensor fails to follow both the shape of the $P_{{\text{O}}_2}$ signal and its peak-to-peak amplitude.