Nasal mask

Abstract

A CPAP system is described for improved respiratory therapy of patients. In particular a patient interface is disclosed with an outlet vent with lower noise levels and more diffused outlet flow over prior art outlet vents. The outlet vent includes a main vent which is diffused and muffled and a higher resistance vent provided in case the main vent is blocked. The outlet vent is removable for easy maintenance and provides indication to the user when maintenance is required. The outlet vent described may be used on nasal masks, mouthpieces and patient interfaces generally.

The claims defining the invention are as follows:  
     
         1 . In a device for delivering a supply of gases to a user comprising: 
 a patient interface, in use in fluid communication with said supply of gases and supplying said gases to said user, and at least one outlet vent integrated with or in adjacent fluid communication the improvement comprising a removable diffusing member adapted to in use covering said vent, and diffuse a substantial portion of the expired gases of said user.    
     
     
         2 . In a device for delivering a supply of gases to a user as claimed in  claim 1  the improvement further comprising said removable member in use diffusing and audibly muffling a substantial portion of the expired gases of said user.  
     
     
         3 . In a device for delivering a supply of gases to a user as claimed in  claim 2  the improvement further comprising said outlet means including at least one low resistance outlet and at least one high resistance outlet through which the expired gases of said user flow out through.  
     
     
         4 . In a device for delivering a supply of gases to a user as claimed in  claim 3  the improvement further comprising during normal use the majority of said expired gases passing from said vent and out through said low resistance outlet, whereby if the majority of said expired gases are substantially prevented from passing through said low resistance outlet, the majority of said expiratory gases passing out said high resistance outlet.  
     
     
         5 . In a device for delivering a supply of gases to a user as claimed in  claim 3  or  4  the improvement further comprising said high resistance outlet is comprised of apertures in said patient interface or said removable member or in the intersection therebetween.  
     
     
         6 . In a device for delivering a supply of gases to a user as claimed in  claim 3  or  4  the improvement further comprising said high resistance outlet is adapted such that in use is said low resistance outlet is blocked or has significant increase in resistance, said high resistance outlet vents a sufficient flow gas so as to prevent rebreathing of carbon dioxide by said user.  
     
     
         7 . In a device for delivering a supply of gases to a user as claimed in  claim 3  or  4  the improvement further comprising said removable member comprises a frame member and a disposable medium in use juxtaposed between said frame member and said vent, said low resistance outlet comprising the flow of said expired gases through said disposable medium.  
     
     
         8 . In a device for delivering a supply of gases to a user as claimed in  claim 7  the improvement further comprising said disposable medium reducing the external audible noise level and diffusing the flow pattern that would otherwise occur from said gases flowing through said vent.  
     
     
         9 . In a device for delivering a supply of gases to a user as claimed in  claim 7  the improvement further comprising said disposable medium is a filter material.  
     
     
         10 . In a device for delivering a supply of gases to a user as claimed in any of  claims 1  to  4  wherein said patient interface comprises a nasal mask having a hard body portion, an inlet to said body portion receiving said supply of gases, sealing means engaged with said body portion, and adapted to seal against the facial contours of said user, and means of securement to said user providing a compressive force on said sealing means to ensure said supply of gases is delivered to a user without significant leakage, said vent comprising at least one aperture in said body portion.  
     
     
         11 . In a CPAP system for delivering gases to a user including a pressurised source of gases, transport means in fluid communication with said pressurised source adapted to convey said gases, and a patient interface in fluid communication with said transport means in use delivering said gases to said user, said patient interface including: 
 outlet means having at least one outlet vent, and a removable diffusing member covering said vent, said outlet means in use passing a substantial portion of the expired gases of said user.    
     
     
         12 . In a CPAP system as claimed in  claim 11  the improvement further comprising said patient interface is a nasal mask.  
     
     
         13 . A removable diffusing member for covering at least one vent or adjacent a gases delivery patient interface, comprising: a body adapted to in use pass a substantial portion of expired gases from a user; and means for removably connecting said body on or over said at least one vent.  
     
     
         14 . A removable diffusing member as claimed in  claim 13  wherein said removable diffusing member is adapted to in use diffuse and audibly muffle a substantial portion of the expired gases of a user flowing out from said at least one vent.  
     
     
         15 . A removable diffusing member as claimed in  claim 13  or  14 , wherein said body includes a frame member and a disposable medium, said disposable medium adapted to be juxtaposed in use between said frame member and said at least one vent, and in use a low resistance outlet being formed by the flow of expired gases through said disposable medium, said removable diffusing member further comprising a high resistance outlet for the flow of expired gases if said low resistance outlet in use becomes blocked.  
     
     
         16 . A removable diffusing member as claimed in  claim 15  wherein said disposable medium is a filter material.