Fig. 2From: Characteristics of the nocturnal desaturation waveform pattern of SpO2 in COPD patients: an observational study(adapted from reference with permission)Characteristics of the nocturnal waveform pattern of SpO2 in COPD patients with nocturnal desaturation. A Sustained pattern, B periodic pattern and C intermittent pattern were classified based on the algorithm (Patients and Methods) ([12]Back to article page