An improved methodology and systems for delivery of breathing gas such as for the treatment of obstructive sleep apena through application of alternating high and low level positive airway pressure within the airway of the patient with the high and low airway pressure being coordinated with the spontaneous...http://www.google.com.hk/patents/US6539940?utm_source=gb-gplus-share專利 US6539940 - Breathing gas delivery method and apparatus
