CPAP (Constant positive airway pressure) is an effective method of treating sleep apnea or Sleeping disorders. It also may be used to treat preterm infants who have underdeveloped lungs. CPAP-therapy for patients with obstructive sleep apnea syndrome is now universally accepted. Before prescribing CPAP-therapy, a Polysomnography is required or in other words a Sleep Study. PSG is used to diagnose sleep disorders. It includes for symptoms of sleep apnea, a disorder in which breathing constantly stops and restarts during sleep.