Automated Control for Detection of Flow Limitation

摘要

A respiratory flow limitation detection device, which can include an airway pressure treatment generator, determines a flow limitation measure (506) based one or more shape indices for detecting partial obstruction and a measure of a patient's ventilation or respiratory duty cycle. The shape indices may be based on function(s) that ascertain the likelihood of the presence of M-shaped breathing patterns and/or chair-shaped breathing patterns. The measure of ventilation may be based on analysis of current and prior tidal volumes to detect a less than normal patient ventilation. The duty cycle measure may be a ratio of current and prior measures of inspiratory time to respiratory cycle time to detect an increase in the patient's inspiratory cycle time relative to the respiratory cycle time. A pressure setting based on the flow limitation may then be used to adjust the treatment pressure to ameliorate the patient's detected flow limitation condition. determining a shape index indicative of a pattern of flow limitation from a measure of respiratory flow; determining a ventilation measure or a breath duty cycle measure from the measure of respiratory flow deriving a flow limitation measure as a function of the determined shape index and either or both of the determined ventilation measure and the determined breathing cycle measure