Headgear tensioning for respiratory mask

Abstract

A patient interface assembly is configured to deliver a positively pressurized flow of breathable gas to a patient's airways. The patient interface assembly includes a patient interface configured to sealingly engage the patient's face and comprises a chamber configured to receive the pressurized flow of breathable gas. The patient interface assembly also includes headgear configured to support the patient interface on the patient's head and be tightened to one of a plurality of discrete tension settings. The headgear includes a tensioning element that is configured to contract in length to one of a plurality of discrete lengths when subjected to an electrical signal. Each discrete length of the tensioning element corresponds to a respective one of the plurality of discrete headgear tension settings.

1 - 20 . (canceled) 
     
     
         21 . A patient interface assembly configured to deliver a positively pressurized flow of breathable gas to a patient's airways, the patient interface assembly comprising:
 a patient interface configured to sealingly engage the patient's face, the patient interface comprising a chamber configured to receive the pressurized flow of breathable gas; and   headgear configured to support the patient interface on the patient's head and be tightened to one of a plurality of discrete tension settings, the headgear comprising a tensioning element,   wherein the tensioning element is configured to contract in length to one of a plurality of discrete lengths when subjected to an electrical signal, and   wherein each discrete length of the tensioning element corresponds to a respective one of the plurality of discrete headgear tension settings.   
     
     
         22 . The patient interface assembly of  claim 21 , wherein each one of the plurality of discrete lengths of the tensioning element corresponds to a respective magnitude of electrical energy. 
     
     
         23 . The patient interface assembly of  claim 21 , wherein the patient interface is configured to deliver the breathable gas to the patient at one of a plurality of therapy pressures, and wherein each discrete headgear tension setting corresponds to a respective one of the plurality of therapy pressures and is a minimum headgear tension capable of maintaining a seal between the patient interface and the patient's face at the respective one of the therapy pressures. 
     
     
         24 . The patient interface assembly of  claim 21 , wherein the tensioning element is configured to increase the tension in the headgear when the tensioning element is actuated. 
     
     
         25 . The patient interface assembly of  claim 21 , wherein the tensioning element is a piezo element. 
     
     
         26 . The patient interface assembly of  claim 25 , wherein the tensioning element is an electro-active polymer. 
     
     
         27 . The patient interface assembly of  claim 21 , wherein the tensioning element is incorporated into a rear portion of the headgear. 
     
     
         28 . The patient interface assembly of  claim 21 , wherein the tensioning element is incorporated into a side portion of the headgear. 
     
     
         29 . The patient interface assembly of  claim 21 , wherein each one of the plurality of discrete lengths of the tensioning element corresponds to a respective magnitude of electrical energy,
 wherein the patient interface is configured to deliver the breathable gas to the patient at one of a plurality of therapy pressures, and wherein each discrete headgear tension setting corresponds to a respective one of the plurality of therapy pressures and is a minimum headgear tension capable of maintaining a seal between the patient interface and the patient's face at the respective one of the therapy pressures,   wherein the tensioning element is configured to increase the tension in the headgear when the tensioning element is actuated,   wherein the tensioning element is an electro-active polymer, and   wherein the tensioning element is incorporated into a side portion of the headgear or a rear portion of the headgear.   
     
     
         30 . A respiratory device configured to deliver a flow of positive pressure gas to a patient's airways, the respiratory device comprising:
 a flow generator configured to pressurize the flow of gas;   the patient interface assembly of  claim 21 ;   an air delivery tube configured to be connected to the flow generator and the patient interface assembly and configured to deliver the pressurized gas to the patient interface; and   a controller configured to actuate the tensioning element.   
     
     
         31 . A patient interface assembly configured to deliver a positively pressurized flow of breathable gas to a patient's airways, the patient interface assembly comprising:
 a cushion configured to sealingly engage the patient's face;   a frame to which the cushion is mounted, the cushion and the frame together forming a chamber configured to receive the pressurized flow of breathable gas, the frame comprising a plurality of headgear connectors; and   headgear configured to support the cushion and the frame on the patient's head and be tightened to one of a plurality of discrete tension settings, the headgear comprising:
 at least one tensioning element configured to contract when subjected to an electrical signal; 
 a pair of side straps configured to secure the headgear to the headgear connectors; and 
 a rear strap connecting the pair of side straps and configured to engage a rear side of the patient's head, 
   wherein the at least one tensioning element is configured to contract in length to one of a plurality of discrete lengths when subjected to an electrical signal, and   wherein each discrete length of the at least one tensioning element corresponds to a respective one of the plurality of discrete headgear tension settings.   
     
     
         32 . The patient interface assembly of  claim 31 , wherein each one of the plurality of discrete lengths of the at least one tensioning element corresponds to a respective magnitude of electrical energy. 
     
     
         33 . The patient interface assembly of  claim 31 , wherein the patient interface is configured to deliver the breathable gas to the patient at one of a plurality of therapy pressures, and wherein each discrete headgear tension setting corresponds to a respective one of the plurality of therapy pressures and is a minimum headgear tension capable of maintaining a seal between the patient interface and the patient's face at the respective one of the therapy pressures. 
     
     
         34 . The patient interface assembly of  claim 31 , wherein the at least one tensioning element is configured to increase the tension in the headgear when the at least one tensioning element is actuated. 
     
     
         35 . The patient interface assembly of  claim 31 , wherein the at least one tensioning element is a piezo element. 
     
     
         36 . The patient interface assembly of  claim 35 , wherein the at least one tensioning element is an electro-active polymer. 
     
     
         37 . The patient interface assembly of  claim 31 , wherein the at least one tensioning element is incorporated into the rear strap of the headgear. 
     
     
         38 . The patient interface assembly of  claim 31 , wherein the at least one tensioning element is incorporated into the side straps of the headgear. 
     
     
         39 . The patient interface assembly of  claim 31 , wherein each one of the plurality of discrete lengths of the at least one tensioning element corresponds to a respective magnitude of electrical energy,
 wherein the patient interface is configured to deliver the breathable gas to the patient at one of a plurality of therapy pressures, and wherein each discrete headgear tension setting corresponds to a respective one of the plurality of therapy pressures and is a minimum headgear tension capable of maintaining a seal between the patient interface and the patient's face at the respective one of the therapy pressures,   wherein the at least one tensioning element is configured to increase the tension in the headgear when the at least one tensioning element is actuated,   wherein the at least one tensioning element is an electro-active polymer, and   wherein the at least one tensioning element is incorporated into the side straps of the headgear or the rear strap of the headgear.   
     
     
         40 . A respiratory device configured to deliver a flow of positive pressure gas to a patient's airways, the respiratory device comprising:
 a flow generator configured to pressurize the flow of gas;   the patient interface assembly of  claim 31 ;   an air delivery tube configured to be connected to the flow generator and the patient interface assembly and configured to deliver the pressurized gas to the patient interface; and   a controller configured to actuate the at least one tensioning element.