Information is collected on the function of breathing, the brain, the heart and the muscles. In addition, the stages of sleep, awakenings, desaturations (drop in oxygen, arrhythmias/tachycardias and bradycardias), limb movements, apneas (full interruption of the air flow to the lungs) and hypopneas (interruption of the air flow to the lungs by at least 70%) are recorded. Furthermore, a polysomnography can be performed through positive pressure ventilation (pressure titration study), a sleep study which uses respiratory equipment for the treatment of sleep apnea or hypoventilation syndromes (obesity, neurological/neuromuscular diseases, respiratory diseases).