In a respiratory apparatus for treatment of sleep apnea and other disorders associated with an obstruction of a patient's airway and which uses an airflow signal, an obstruction index is generated which detects the flattening of the inspiratory portion of the airflow. The obstruction index is used to...http://www.google.de/patents/US7013893?utm_source=gb-gplus-sharePatent US7013893 - Respiratory apparatus with improved flow-flattening detection
