Method and apparatus for providing variable positive airway pressure

Abstract

A method and apparatus for treating a breathing disorder and, more particularly, a method and apparatus for providing a pressurized air flow to an airway of a patient to treat congestive heart failure in combination with Cheyne-Stokes respiration and/or sleep apnea or other breathing disorders. A positive airway pressure ventilator is utilized in combination with an algorithm that adjusts IPAP and EPAP in order to counter a Cheyne-Stokes breathing pattern. Cheyne-Stokes respiration is detected by monitoring a peak flow of the patient.

1 . A system for delivering a flow of gas to an airway of a patient, the system comprising: 
 a gas flow generating system adapted to generate a flow of gas;    a patient circuit coupled to the gas flow generating system and adapted to communicate the flow of gas to an airway of a patient;    a sensor associated with the gas flow generating system or the patient circuit and adapted to monitor a characteristic associated with the flow of gas within the patient circuit and to transmit a signal indicative thereof; and    a controller operatively coupled to the gas flow generating system and the sensor, wherein the controller determines whether the patient is experience respiratory activity indicative of Cheyne-Stokes respiration based on the signal, wherein the controller causes the gas flow generating system to deliver a pressure support therapy, and wherein the controller adjusts an expiratory positive airway pressure of the pressure support therapy responsive to the patient experiencing respiratory activity indicative of Cheyne-Stokes respiration.    
   
   
       2 . The system of  claim 1 , wherein the pressure support therapy is: 
 a continuous positive airway pressure support therapy,    a bi-level positive airway pressure support therapy,    a pressure support therapy in which a pressure of the flow of gas varies based on flow,    an auto-titration pressure support therapy in which a pressure of the flow of gas varies based on a monitored condition of the patient    
   
   
       3 . The system of  claim 1 , wherein the pressure support therapy is a an auto-titrating continuous pressure support therapy in which a continuous positive airway pressure is delivered to the patient, and wherein a level of the continuous positive airway pressure varies based on a monitored condition of the patient.  
   
   
       4 . The system of  claim 3 , wherein a pressure of the flow of gas delivered to the patient during at least a portion of an expiratory phase varies based on a rate of the flow of gas.  
   
   
       5 . The system of  claim 1 , wherein the pressure support therapy is a an auto-titrating bi-level pressure support therapy in which a pressure of the flow of gas provided to the patient alternates between an inspiratory positive airway pressure and the expiratory positive airway pressure in synchronization with the patient's respiration, and wherein a level of the an inspiratory positive airway pressure, the expiratory positive airway pressure, or both vary based on a monitored condition of the patient.  
   
   
       6 . The system of  claim 5 , wherein a pressure of the flow of gas delivered to the patient during at least a portion of an expiratory phase, during at least a portion of an inspiratory phase, or during both at least a portion of the expiratory phase and at least a portion of the inspiratory phase varies based on a rate of the flow of gas.  
   
   
       7 . The system of  claim 1 , wherein the sensor is a flow sensor and the signal is a flow signal, and wherein the controller determines whether the patient is experiencing respiratory activity indicative of Cheyne-Stokes respiration by monitoring a peak flow from the flow signal.  
   
   
       8 . The system of  claim 1 , wherein the gas flow generating system includes: 
 a pressure generator adapted to generate the flow of gas; and    a pressure control valve associated with the pressure generator or the patient circuit to control a pressure of the flow of gas delivered to a patient by the patient circuit.    
   
   
       9 . The system of  claim 1 , wherein the controller detects I/E transitions between an inspiratory phase and an expiratory phase of a respiratory cycle, and causes the gas flow generating system to deliver a machine breath responsive to a failure to detect a patient initiated breath between within a predetermined period of time.  
   
   
       10 . A system for delivering a flow of gas to an airway of a patient, the system comprising: 
 gas flow generating means for generating a flow of gas;    gas flow carrying means for communicating the flow of gas to an airway of a patient;    sensing means for monitoring a characteristic associated with the flow of gas; and    controlling means for (i) determining whether the patient is experience respiratory activity indicative of Cheyne-Stokes respiration based on an output of the sensing means, (ii) causing the gas flow generating means to deliver a pressure support therapy, and (iii) adjusting an expiratory positive airway pressure of the pressure support therapy responsive to the patient experiencing respiratory activity indicative of Cheyne-Stokes respiration.    
   
   
       11 . The system of  claim 10 , wherein the pressure support therapy is: 
 a continuous positive airway pressure support therapy,    a bi-level positive airway pressure support therapy,    a pressure support therapy in which a pressure of the flow of gas varies based on flow,    an auto-titration pressure support therapy in which a pressure of the flow of gas varies based on a monitored condition of the patient    
   
   
       12 . The system of  claim 10 , wherein the pressure support therapy is a an auto-titrating continuous pressure support therapy in which a continuous positive airway pressure is delivered to the patient, and wherein a level of the continuous positive airway pressure varies based on a monitored condition of the patient.  
   
   
       13 . The system of  claim 12 , wherein a pressure of the flow of gas delivered to the patient during at least a portion of an expiratory phase varies based on a rate of the flow of gas.  
   
   
       14 . The system of  claim 10 , wherein the pressure support therapy is a an auto-titrating bi-level pressure support therapy in which a pressure of the flow of gas provided to the patient alternates between an inspiratory positive airway pressure and the expiratory positive airway pressure in synchronization with the patient's respiration, and wherein a level of the an inspiratory positive airway pressure, the expiratory positive airway pressure, or both vary based on a monitored condition of the patient.  
   
   
       15 . The system of  claim 14 , wherein a pressure of the flow of gas delivered to the patient during at least a portion of an expiratory phase, during at least a portion of an inspiratory phase, or during both at least a portion of the expiratory phase and at least a portion of the inspiratory phase varies based on a rate of the flow of gas.  
   
   
       16 . The system of  claim 10 , wherein the sensing means a flow sensor, and wherein the controlling means determines whether the patient is experiencing respiratory activity indicative of Cheyne-Stokes respiration by monitoring a peak flow based on the output of the flow sensor.  
   
   
       17 . The system of  claim 10 , wherein the gas flow generating means includes: 
 a pressure generator adapted to generate the flow of gas; and    a pressure control valve associated with the pressure generator or the patient circuit to control a pressure of the flow of gas delivered to a patient by the patient circuit.    
   
   
       18 . The system of  claim 10 , wherein the controlling means detects I/E transitions between an inspiratory phase and an expiratory phase of a respiratory cycle, and causes the gas flow generating means to deliver a machine breath responsive to a failure to detect a patient initiated breath between within a predetermined period of time.  
   
   
       19 . A method for delivering pressurized gas to an airway of a patient, the method comprising the steps of: 
 delivering a flow of gas to the airway of the patient from a source of gas via a patient circuit according or a pressure support therapy;    sensing a characteristic associated with a flow of gas;    determining whether the patient is experience respiratory activity indicative of Cheyne-Stokes respiration based on the characteristic; and    adjusting an expiratory positive airway pressure of the pressure support therapy responsive to the patient experiencing respiratory activity indicative of Cheyne-Stokes respiration.    
   
   
       20 . The method of  claim 19 , wherein the pressure support therapy is: 
 a continuous positive airway pressure support therapy,    a bi-level positive airway pressure support therapy,    a pressure support therapy in which a pressure of the flow of gas varies based on flow,    an auto-titration pressure support therapy in which a pressure of the flow of gas varies based on a monitored condition of the patient    
   
   
       21 . The method of  claim 19 , wherein the pressure support therapy is a an auto-titrating continuous pressure support therapy such that delivering a flow of gas includes: 
 providing a continuous positive airway pressure to the patient;    monitoring a condition of the patient; and    adjusting a level of the continuous positive airway pressure varies based on the monitored condition.    
   
   
       22 . The method of  claim 21 , further comprising varying pressure of the flow of gas delivered to the patient during at least a portion of an expiratory phase varies based on a rate of the flow of gas.  
   
   
       23 . The method of  claim 19 , wherein the pressure support therapy is a an auto-titrating bi-level pressure support therapy such that delivering a flow of gas includes: 
 alternating a pressure of the flow of gas provided to the patient between an inspiratory positive airway pressure and the expiratory positive airway pressure in synchronization with the patient's respiration; and    adjusting a level of the an inspiratory positive airway pressure, a level of the expiratory positive airway pressure, or both the level of the an inspiratory positive airway pressure and the level of the expiratory positive airway pressure based on a monitored condition of the patient.    
   
   
       24 . The method of  claim 23 , further comprising varying a pressure of the flow of gas delivered to the patient during at least a portion of an expiratory phase, during at least a portion of an inspiratory phase, or during both at least a portion of the expiratory phase and at least a portion of the inspiratory phase varies based on a rate of the flow of gas.  
   
   
       25 . The method of  claim 19 , wherein sensing a characteristic associated with a flow of gas includes monitoring a flow of gas, and wherein determining whether the patient is experiencing respiratory activity indicative of Cheyne-Stokes respiration includes monitoring a peak flow.  
   
   
       26 . The method of  claim 19 , further comprising: 
 detecting I/E transitions between an inspiratory phase and an expiratory phase of a respiratory cycle; and    delivering a machine generated breath to a patient responsive to a failure to detect a patient initiated breath between within a predetermined period of time.