Breathing assistance apparatus

Abstract

A breathing assistance apparatus is disclosed, for use with delivery of respiratory gases to a patient. The breathing assistance apparatus includes a patient interface, having a body section adapted to cover the nose, or nose and mouth of a patient and a sealing interface. The sealing interface includes at least an outer sealing member. The outer sealing member is adapted to attach to the body section in a sealing manner and has a substantially thin section in at least its nasal bridge region. The thin section is substantially thinner than the rest of the outer sealing member. The patient interface comprises a mask body and a seal assembly. The seal assembly includes a flexible seal, and a rigid seal clip, the seal assembly being removably attached to the mask body via the rigid seal clip. The mask body and rigid seal clip are profiled to match the contours of a user's face so that the seal has a substantially constant wall depth.

What is claimed is: 
     
         1 . A mask assembly for use as part of an apparatus for supplying a flow of respiratory gases to a user comprising:
 a rigid mask body, said rigid mask body including a front side, a rear side, and an outer periphery, the front side including an inlet through which the flow of respiratory gases are provided to an interior of the mask assembly and a plurality of exhaust holes, the rear side and the outer periphery of the rigid mask body comprising an annular channel facing toward a user in use, the annular channel including a first wall and a second wall, the first wall having a first end surface facing toward a user in use, the first end surface defining a mask body bearing surface;   a mask seal assembly comprising a flexible seal and a rigid clip member, the flexible seal having a first side and a second side, the first side of said flexible seal being configured to substantially seal against a portion of a user's face in use, the second side of the flexible seal connected to the rigid clip member, the rigid clip being configured to be snap attachable to the annular channel of the rigid mask body, the rigid clip member including an inner surface, an outer surface, and a raised ridge extending around the rigid clip member, wherein at least a portion of the raised ridge extends along the inner surface and at least a portion of the second side of the flexible seal extends along said portion of the raised ridge, the second side of the flexible seal including a rim disposed inwardly from the inner surface of the rigid clip member, the rim defining a seal bearing surface positioned to bear against the mask body bearing surface when the rigid clip member is connected to the rigid mask body.   
     
     
         2 . The mask assembly according to  claim 1 , wherein the second side of the flexible seal only extends along a portion of the inner surface of the rigid clip member. 
     
     
         3 . The mask assembly according to  claim 1 , wherein the inner surface comprises a first portion and a second portion, the first portion coinciding with the second side of the flexible seal and the second portion extending past the first wall of the rigid mask body. 
     
     
         4 . The mask assembly according to  claim 1 , wherein a least a portion of the raised ridge forms a rearwardly facing surface of the rigid clip member. 
     
     
         5 . The mask assembly according to  claim 4 , wherein at least a portion of the second side of the flexible seal extends along the rearwardly facing surface. 
     
     
         6 . The mask assembly according to  claim 1 , wherein the rigid clip is connected to the rigid mask body and the rim is pressed against the mask body bearing surface. 
     
     
         7 . The mask assembly according to  claim 1 , wherein the raised ridge runs continuously around the inside perimeter of the rigid clip member. 
     
     
         8 . The mask assembly according to  claim 7 , wherein the rim is configured to provide a small contact area with the mask body bearing surface when the rigid clip is connected to the rigid mask body. 
     
     
         9 . A mask assembly for use as part of an apparatus for supplying a flow of respiratory gases to a user comprising:
 a rigid mask body including a front side and a rear side, the front side including an inlet, through which the flow of respiratory gases are provided to an interior of the mask assembly, and a plurality of exhaust holes, the rear side of the mask body comprising a first annular wall having a first end surface facing toward a user in use, the first end surface defining a mask body bearing surface;   a mask seal assembly comprising a flexible seal and a rigid clip member, the flexible seal having a first side and a second side, the first side of said seal being configured to substantially seal against a portion of a user's face in use, the second side of the flexible seal connected to the rigid clip member, the rigid clip being configured to be attachable to the rear side of the rigid mask body, the rigid clip member including an inner surface, an outer surface, and a raised ridge extending around the rigid clip member, wherein at least a portion of the raised ridge extends along the inner surface and at least a portion of the second side of the flexible seal extends along said portion, the second side of the flexible seal including a rim defining a seal bearing surface positioned to bear against the mask body bearing surface when the rigid clip member is connected to the rigid mask body.   
     
     
         10 . The mask assembly according to  claim 9 , wherein the second side of the flexible seal only extends along a portion of the inner surface of the rigid clip member. 
     
     
         11 . The mask assembly according to  claim 9 , wherein the inner surface comprises a first portion and a second portion, the first portion coinciding with the second side of the flexible seal and the second portion extending past the first wall of the rigid mask body. 
     
     
         12 . The mask assembly according to  claim 9 , wherein a least a portion of the raised ridge forms a rearwardly facing surface of the rigid clip member. 
     
     
         13 . The mask assembly according to  claim 12 , wherein at least a portion of the second side of the flexible seal extends along the rearwardly facing surface. 
     
     
         14 . The mask assembly according to  claim 9 , wherein the rear side of the rigid mask body comprises an annular channel disposed at an outer periphery of the rigid mask body, facing toward a user in use, the annular channel including the first annular wall and a second annular wall. 
     
     
         15 . The mask assembly according to  claim 9 , wherein the rigid clip is configured to be snap attachable to the rigid mask body. 
     
     
         16 . The mask assembly according to  claim 9 , wherein the rim is disposed inwardly from the raised ridge of rigid clip member. 
     
     
         17 . The mask assembly according to  claim 9 , wherein the rigid clip is connected to the rigid mask body and the rim is pressed against the mask body bearing surface. 
     
     
         18 . The mask assembly according to  claim 9 , wherein the raised ridge runs around the inside perimeter of the rigid clip member. 
     
     
         19 . The mask assembly according to  claim 9 , wherein the rim is configured to provide a small contact area with the mask body bearing surface when the rigid clip is connected to the rigid mask body. 
     
     
         20 . The mask according to  claim 19 , wherein the rim extends continuously along the perimeter of the raised ridge of the rigid clip member.