Adaptive patient circuit compensation with pressure sensor at mask apparatus

Abstract

In certain embodiments, a system for providing respiratory therapy is provided. The system comprises a pressure generator for generating a pressurized flow of breathable gas; a subject interface for guiding the pressurized flow of breathable gas to a point of delivery at or near the airway of the subject, wherein the subject interface causes a pressure drop between an output of the pressure generator and the point of delivery; one or more sensors for generating output signals conveying information related to gas parameters of the pressurized flow of breathable gas; one or more processors configured to adjust one or more model parameters of a parameter-based model that models the subject interface; estimate the pressure drop between the output of the pressure generator and the point of delivery based on the adjusted model parameters; and adjust levels of the gas parameters based on the estimated pressure drop.

What is claimed is: 
     
         1 . A system for providing respiratory therapy during a therapy session to a subject, the system comprising:
 a pressure generator configured to generate a pressurized flow of breathable gas for delivery to the airway of the subject, the pressure generator having an output configured to expel the pressurized flow of breathable gas;   a subject interface configured to guide the pressurized flow of breathable gas from the output of the pressure generator to a point of delivery at or near the airway of the subject, wherein the subject interface causes a pressure drop between the output of the pressure generator and the point of delivery during delivery of the pressurized flow of breathable gas;   one or more sensors configured to generate output signals conveying information related to one or more gas parameters of the pressurized flow of breathable gas;   one or more processors configured to execute processing modules, the processing modules comprising:
 a model module configured to adjust one or more model parameters of a parameter-based model that models the subject interface, the one or more model parameters being different than the one or more gas parameters, and wherein the parameter-based model includes one or more model parameters related to pneumatic impedance of the subject interface; 
 an estimation module configured to estimate the pressure drop between the output of the pressure generator and the point of delivery during delivery of the pressurized flow of breathable gas based on the generated output signal and based on the one or more adjusted model parameters of the parameter-based models; and 
 a control module configured to adjust levels of one or more gas parameters of the pressurized flow of breathable gas based on the estimated pressure drop. 
   
     
     
         2 . The system of  claim 1 , further comprising:
 wherein adjustments by the control module are further based on the parameter-based model.   
     
     
         3 . The system of  claim 1 , further comprising:
 a target module configured to determine a target pressure for the pressurized flow of breathable gas that compensates for or one or more effects of a transport delay of a pressure wave propagating through the subject interface during the therapy session, and   wherein the control module is further configured to adjust levels of one or more gas parameters of the pressurized flow of breathable gas based on the target pressure.   
     
     
         4 . The system of  claim 3 , further comprising:
 a device pressure module configured to determine a device pressure at or near the output of the pressure generator;   an error module configured to determine a pressure error based on a difference between the target pressure and the determined device pressure; and   wherein the adjustments by the model module are further based on the device pressure, and wherein adjustments by the control module are further based on the pressure error.   
     
     
         5 . The system of  claim 4 , wherein one of the one or more sensors is disposed at or near the output of the pressure generator, and wherein determination of the device pressure is based on output signals generated by the sensor disposed at or near the output of the pressure generator. 
     
     
         6 . The system of  claim 1 , wherein operations of one or more sensors and the one or more processors are performed in an ongoing manner during the therapy session. 
     
     
         7 . A method for providing respiratory therapy during a therapy session to a subject implemented in a system including a pressure generator, a subject interface, and one or more sensors, the method comprising:
 generating a pressurized flow of breathable gas for delivery to the airway of the subject via an output of the pressure generator;   guiding the pressurized flow of breathable gas from the output of the pressure generator to a point of delivery at or near the airway of the subject via the subject interface, wherein the subject interface causes a pressure drop between the output of the pressure generator and the point of delivery during delivery of the pressurized flow of breathable gas;   generating output signals conveying information related to one or more gas parameters of the pressurized flow of breathable gas;   adjusting one or more model parameters of a parameter-based model that models the subject interface, the one or more model parameters being different than the one or more gas parameters, and wherein the parameter-based model includes one or more model parameters related to pneumatic impedance of the subject interface;   estimating the pressure drop between the output of the pressure generator and the point of delivery during delivery of the pressurized flow of breathable gas based on the generated output signal and based on the one or more adjusted model parameters of the parameter-based models; and   adjusting levels of one or more gas parameters of the pressurized flow of breathable gas based on the estimated pressure drop.   
     
     
         8 . The method of  claim 7 , wherein adjusting levels of one or more gas parameters of the pressurized flow of breathable gas is further based on the parameter-based model. 
     
     
         9 . The method of  claim 7 , further comprising:
 determining a target pressure for the pressurized flow of breathable gas that compensates for or one or more effects of a transport delay of a pressure wave propagating through the subject interface during the therapy session, and wherein adjusting levels of one or more gas parameters of the pressurized flow of breathable gas is further based on the target pressure.   
     
     
         10 . The method of  claim 9 , further comprising:
 determining a device pressure at or near the output of the pressure generator;   determining a pressure error based on a difference between the target pressure and the determined device pressure; and   wherein adjusting one or more model parameters of the parameter-based model is further based on the device pressure, and wherein adjusting levels of one or more gas parameters of the pressurized flow of breathable gas is further based on the pressure error.   
     
     
         11 . The method of  claim 10 , determining the device pressure is based on output signals generated by a sensor disposed at or near the output of the pressure generator. 
     
     
         12 . The method of  claim 7 , wherein operations of the method are performed in an ongoing manner during the therapy session. 
     
     
         13 . A system configured providing respiratory therapy during a therapy session to a subject, the system comprising:
 pressure means for generating a pressurized flow of breathable gas for delivery to the airway of the subject;   guiding means for guiding the pressurized flow of breathable gas from an output of the pressure means to a point of delivery at or near the airway of the subject, wherein the guiding means causes a pressure drop between the output of the pressure means and the point of delivery during delivery of the pressurized flow of breathable gas;   means for generating output signals conveying information related to one or more gas parameters of the pressurized flow of breathable gas, wherein the output signals are generated in an ongoing manner during the therapy session;   means for adjusting one or more model parameters of a parameter-based model that models the subject interface, the one or more model parameters being different than the one or more gas parameters, and wherein the parameter-based model includes one or more model parameters related to pneumatic impedance of the subject interface;   means for estimating the pressure drop between the output of the pressure generator and the point of delivery during delivery of the pressurized flow of breathable gas based on the generated output signal and based on the one or more adjusted model parameters of the parameter-based models; and   means for adjusting levels of one or more gas parameters of the pressurized flow of breathable gas based on the estimated pressure drop.   
     
     
         14 . The system of  claim 13 , wherein adjusting levels of one or more gas parameters of the pressurized flow of breathable gas is further based on the parameter-based model. 
     
     
         15 . The system of  claim 13 , further comprising:
 means for determining a target pressure for the pressurized flow of breathable gas that compensates for or one or more effects of a transport delay of a pressure wave propagating through the guiding means during the therapy session, and wherein adjusting levels of one or more gas parameters of the pressurized flow of breathable gas is further based on the target pressure.   
     
     
         16 . The method of  claim 15 , further comprising:
 means for determining a device pressure at or near the output of the pressure means;   means for determining a pressure error based on a difference between the target pressure and the determined device pressure; and   wherein adjusting one or more model parameters of the parameter-based model is further based on the device pressure, and wherein adjusting levels of one or more gas parameters of the pressurized flow of breathable gas is further based on the pressure error.   
     
     
         17 . The system of  claim 16 , wherein determining the device pressure is based on output signals generated by a means for generating output signals disposed at or near the output of the pressure means. 
     
     
         18 . The system of  claim 13 , wherein operations of the system are performed in an ongoing manner during the therapy session.