Examples of nocturnal respiratory recordings. The upper part of each panel is the flow signal from the thermocouples and the lower is the impedance signal from the ECG electrodes. The duration of each example is 6 minutes. Panel A depicts an unequivocal period of Cheyne-Stokes respiration. Panel B was interpreted as normal by the software of the recording device, but was interpreted by us as Cheyne-Stokes respiration. Panel C is an example of obstructive sleep apnoeas and panel D is a period of Cheyne-Stokes respiration with a small obstructive component, classified by us as Cheyne-Stokes respiration rather than obstructive sleep apnoeas.