System and Method for Improved Treatment of Sleeping Disorders using Therapeutic Positive Airway Pressure

Abstract

Described is a method and system providing therapeutic positive airway pressure to a particular area of patient's airways. The system may include a flow generator and a processing arrangement. The flow generator supplies an airflow to an airway of the patient. The processing arrangement is connected to the flow generator to control a supply pressure at which the airflow is generated by the flow generator. The processing arrangement continuously adjusts the supply pressure to maintain a pressure in a predetermined portion of the patient's airway substantially constant. The predetermined portion of the patient's airway includes a collapsible portion of an upper airway of the patient. The processing arrangement also controls the supply pressure to maintain the pressure in the collapsible portion of the patient's airway at a value at least as great as a tissue pressure below which the collapsible portion collapses.

1 - 22 . (canceled) 
     
     
         23 . A device for treatment of a sleeping disorder, comprising:
 a flow generator configured to supply air to an airway of a patient at a predetermined pressure P A ;   a processing arrangement operably connected to the flow generator to maintain a gas pressure within a predetermined portion of the patient's airway within a desired range by adjusting one or both of the rate of airflow and a pressure supplied by the flow generator.   
     
     
         24 . The device of  claim 23 , wherein the processing arrangement is configured to maintain a substantially constant pressure C P  within the patient's airway, the pressure C P  being selected to prevent a collapse of the patient's airway. 
     
     
         25 . The device of  claim 24 , further comprising a mask connected to the tube and configured to connect the flow generator to the airway of the patient. 
     
     
         26 . The device of  claim 25 , further comprising a flow tube extending from the flow generator to the airway of the patient, the flow tube having a resistance R AB , wherein the value R AB  is measured when the flow generator is providing the airflow and the mask is open to the atmosphere. 
     
     
         27 . The device of  claim 26 , wherein the flow generator is configured to provide the airflow at one of a constant and a variable flow rate. 
     
     
         28 . The device of  claim 26 , wherein the pressure P A  may be continuously adjusted according to the formula: P A =C P +R AB *F S +R BC *Fp, wherein:
 R BC  is a resistance in the predetermined portion of the patient's airway;   F s  is an instantaneous rate of flow of air flowing from the flow generator to the patient;   F p  is an instantaneous rate of flow of air via inhalation and exhalation of the patient;   wherein the values of F S  and F P  are negative during expiration and positive during inspiration.   
     
     
         29 . The device of  claim 26 , wherein the pressure P A  is continuously adjusted according to R AB  and R BC , wherein R BC  is a resistance in the predetermined portion of the patient's airway. 
     
     
         30 . The device of  claim 28 , wherein the value of R BC  may be determined from one of (a) a resistance measured from the patient, (b) a fixed standardized resistance, (c) a resistance based on a rhinometric analysis of the patient and (d) an estimated resistance based on a pathology of the patient's nose. 
     
     
         31 . The device of  claim 29 , wherein the value of R BC  may be determined from one of (a) a resistance measured from the patient, (b) a fixed standardized resistance, (c) a resistance based on a rhinometric analysis of the patient and (d) an estimated resistance based on a pathology of the patient's nose. 
     
     
         32 . The device of  claim 24 , wherein the pressure C P  is maintained substantially constant throughout one of an entire inspiratory phase and a full respiratory cycle. 
     
     
         33 . The device of  claim 32 , wherein the pressure C P  applied during the expiratory phase is lower than the pressure C P  applied during the inspiratory phase. 
     
     
         34 . The device of  claim 23 , further comprising a venting arrangement configured to prevent the patient from rebreathing exhaled gases. 
     
     
         35 . The device of  claim 34 , wherein the venting arrangement is one of a leak port or a non-rebreathing valve. 
     
     
         36 . The device of  claim 34 , wherein the venting arrangement vents the exhaled gas to the atmosphere. 
     
     
         37 . The device of  claim 28 , further comprising a first pressure sensor coupled to the flow tube and configured to measure a pressure within the flow tube and provide the measured data to the processing arrangement. 
     
     
         38 . The device of  claim 37 , further comprising a second pressure sensor configured to measure a pressure in one of the mask and the flow generator and provide the measured data to the processing arrangement. 
     
     
         39 . The device of  claim 23 , wherein the predetermined portion of the patient's airway is a portion of the upper airway susceptible to collapse. 
     
     
         40 . A method for treating a sleeping disorder, comprising the steps of:
 supplying an airflow to an airway of a patient at a predetermined pressure P A ; and   maintaining a gas pressure within a predetermined portion of the patient's airway within a desired range by adjusting one or both of the rate of airflow and a pressure supplied by the flow generator via a processing arrangement operably connected to a flow generator.   
     
     
         41 . The method according to  claim 40 , wherein the processing arrangement is configured to maintain a substantially constant pressure C P  within the patient's airway, the pressure C P  being selected to prevent a collapse of the patient's airway. 
     
     
         42 . The method according to  claim 41 , wherein the pressure C P  is maintained substantially constant in the predetermined portion throughout one of an entire inspiratory phase and a full respiratory cycle. 
     
     
         43 . The method according to  claim 41 , further comprising the steps of:
 generating the airflow using the flow generator, the flow generator being coupled to the patient's airway by a flow tube; and   providing the airflow to a mask situated over at least one of a nose and a mouth of the patient via the flow tube.   
     
     
         44 . The method according to  claim 40 , further comprising the step of:
 diverting, via a venting arrangement, gases exhaled by the patient from an incoming airflow to prevent re-breathing of the exhaled gases.   
     
     
         45 . The method according to  claim 43 , further comprising the step of:
 determining a supply pressure P A  according to the following formula:
     P   A   =C   P   +R   AB   *Fs+R   BC   *F   P    
   wherein,   P A  is the supply pressure provided by the flow generator;   R AB  is a resistance in the flow tube, wherein the value R AB  is measured when the flow generator is providing the airflow and the mask is opened to the atmosphere;   F s  is an instantaneous rate of flow of air flowing from the flow generator to the patient;   R BC  is a resistance in the predetermined portion of the patient's airway, wherein the value of R BC  may be determined from one of (a) a resistance measured from the patient, (b) a fixed standardized resistance, (c) a resistance based on a rhinometric analysis of the patient and (d) an estimated resistance based on a pathology of the patient's nose; and   F P  is an instantaneous rate of flow of air via inhalation and exhalation of the patient,   wherein the values of F S  and F P  are negative during expiration and positive during inspiration.   
     
     
         46 . The method according to  claim 45 , further comprising the steps of:
 measuring, via a first sensor, a first value of pressure in the flow tube; and   providing the measured data to the processing arrangement.   
     
     
         47 . The method according to  claim 46 , further comprising the steps of:
 measuring, via a second sensor, a second value of pressure within one of the flow generator and the mask; and   providing the measured data to the processing arrangement.