Methods and apparatus for adaptable pressure treatment of sleep disordered breathing

Abstract

Respiratory pressure treatment apparatus include automated methodologies for controlling changes to pressure in the presence of sleep disordered breathing events. In an example apparatus, various levels of expiratory pressure relief can provide different pressure reductions for patient comfort during expiration ( 333 -A, 333 -B, 333 -C). The control parameters for these levels may be automatically modified based on the detection of an open airway. Similarly, in some embodiments, the levels may be automatically adjusted based on a detection of persistent obstruction. In still further embodiments, control parameters associated with a rise time of an early portion of an inspiratory pressure treatment may be automatically adjusted upon detection of flow limitation to permit a change to more aggressive waveforms from more comfortable waveforms for the treatment of sleep disordered breathing events.

1 . A respiratory pressure treatment apparatus comprising:
 a flow generator to generate a flow of breathable gas to a patient interface; and   a controller to control the flow generator to deliver a flow of breathable gas at a patient interface, the flow of breathable gas being synchronized with a respiratory cycle, the flow of breathable gas comprising expiratory pressure portions and inspiratory pressure portions wherein at least one of the expiratory pressure portions is at a pressure lower than at least one of the inspiratory pressure portions,   the controller to control an activation of a pre-termination pressure treatment protocol during a pre-termination period wherein a change to control parameters for setting pressure of the inspiratory pressure portions or the expiratory pressure portion is initiated.   
     
     
         2 . The apparatus of  claim 1  wherein the change to control parameters for setting pressure of the expiratory pressure portion comprises an increase in a reduction in expiratory pressure. 
     
     
         3 . The apparatus of  claim 1  wherein the change to control parameters for setting pressure of the inspiratory pressure portion comprises a decrease in a rise time for an early portion of the inspiratory pressure. 
     
     
         4 . The apparatus of  claim 1  wherein the change to control parameters for setting pressure comprises a ramping down of a peak inspiratory pressure, the ramping down being over a range from a peak inspiratory pressure in treatment before the pre-termination period to a pressure level of an expiratory pressure portion in the treatment before the pre-termination period, the ramping down comprising a gradual reduction of peak inspiratory pressure extending over the pre-termination period. 
     
     
         5 . The apparatus of  claim 1  wherein the controller initiates the pre-termination period as a function of a preset termination time. 
     
     
         6 . The apparatus of  claim 1  wherein the controller initiates the pre-termination period as a function of detection by the controller of a lapsed time in a sleep state attributable to sleep. 
     
     
         7 . The apparatus of  claim 1  wherein the controller initiates the pre-termination period as a function a detection by the controller of a sleep state attributable to wakefulness.