Breathing gas delivery method and apparatus

Abstract

An improved methodology and systems for delivery of breathing gas such as for the treatment of obstructive sleep apnea 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 respiration of the patient, and improved methods and apparatus for triggering and for leak management in such systems.

1 - 10 . (canceled)  
   
   
       11 . A method of medical treatment for a patient comprising the steps of: 
 providing a flow of breathing gas from a source for delivery to an airway of such a patient at pressure magnitudes that vary with such a patient's respiratory cycle;    monitoring a parameter indicative of a flow of the breathing gas flowing between the source and the airway of such a patient;    processing the parameter indicative of the flow to provide a reference indicia; and    utilizing the parameter, the reference indicia, or both the parameter and the reference indicia to apply a variable pressure in the airway of such a patient such that an average of the pressure applied in the airway of such a patient during inspiration is higher than an average of the pressure applied in the airway of such a patient during expiration.    
   
   
       12 . The method of  claim 11 , wherein the parameter indicative of a flow of the breathing gas the monitoring step is an output of a flow sensor disposed so as to measure a flow of the breathing gas between the source and the airway of such as patient.  
   
   
       13 . The method of  claim 11 , wherein the reference indicia is (1) an average flow of breathing gas flowing between the source and such a patient or (2) the average flow of breathing gas flowing between the source and such a patient with an offset.  
   
   
       14 . The method of  claim 11 , wherein the variable pressure includes an inspiratory positive airway pressure (IPAP) and an expiratory positive airway pressure (EPAP) that is less that the IPAP, and wherein the utilizing step includes applying the IPAP during inspiration and the EPAP during expiration.  
   
   
       15 . The method of  claim 14 , further comprising: 
 selecting the IPAP;    selecting the EPAP; or    selecting both the IPAP and the EPAP.    
   
   
       16 . The method of  claim 15 , wherein selecting the IPAP, the EPAP, or both is done manually.  
   
   
       17 . The method of  claim 11 , wherein the pressure applied in the airway of such a patient during inspiration is a pressure sufficient to treat sleep apnea syndrome.  
   
   
       18 . The method of  claim 11 , wherein the pressure applied in the airway of such a patient during inspiration is set based on a sleep study.  
   
   
       19 . The method of  claim 11 , wherein the pressure applied to the airway of such a patient is substantially constant during a majority of an inspiratory phase of such a patient's breathing cycle.  
   
   
       20 . The method of  claim 11 , wherein the step of monitoring the parameter indicative of the flow of the breathing gas is performed repeatedly during the respiratory cycle of such a patient.  
   
   
       21 . A method of medical treatment for a patient comprising the steps of: 
 providing a flow of breathing gas from a source for delivery to an airway of such a patient at pressure magnitudes that vary with such a patient's respiratory cycle;    providing a signal indicative of a characteristic of a flow of the breathing gas flowing between the source and the airway of such a patient;    determining a reference indicia based on the signal; and    applying a variable pressure in the airway of such a patient, based on the signal, the reference indicia, or both the signal and the reference indicia, such that an average of the pressure applied in the airway of such a patient during inspiration is higher than an average of the pressure applied in the airway of such a patient during expiration.    
   
   
       22 . The method of  claim 21 , wherein the signal corresponds to an output of a flow sensor disposed so as to measure a flow of the breathing gas between the source and the airway of such as patient.  
   
   
       23 . The method of  claim 21 , wherein the reference indicia is (1) an average flow of breathing gas flowing between the source and such a patient or (2) the average flow of breathing gas flowing between the source and such a patient with an offset.  
   
   
       24 . The method of  claim 21 , wherein the variable pressure includes an inspiratory positive airway pressure (IPAP) and an expiratory positive airway pressure (EPAP), and wherein the applying step includes providing the IPAP during inspiration and the EPAP during expiration.  
   
   
       25 . The method of  claim 24 , further comprising: 
 selecting the IPAP;    selecting the EPAP; or    selecting both the IPAP and the EPAP.    
   
   
       26 . The method of  claim 25 , wherein selecting the IPAP, the EPAP, or both is done manually.  
   
   
       27 . The method of  claim 21 , wherein the pressure applied in the airway of such a patient during inspiration is a pressure sufficient to treat sleep apnea syndrome.  
   
   
       28 . The method of  claim 21 , wherein the pressure applied in the airway of such a patient during inspiration is set based on a sleep study.  
   
   
       29 . The method of  claim 21 , wherein the pressure applied to the airway of such a patient is substantially constant during a majority of an inspiratory phase of such a patient's breathing cycle.  
   
   
       30 . The method of  claim 21 , wherein the step of providing the signal indicative of the characteristic of the flow of the breathing gas is performed repeatedly during the respiratory cycle of such a patient.