Gas delivery connection assembly

Abstract

Patient gas deliver apparatus includes a gas flow generator, a gas delivery conduit and a patient mask ( 10 ). Connected in series between the conduit and the mask is an assembly ( 20 ) formed in at least two interengaging parts ( 26, 28 ), which may form a housing for an anti-asphyxia valve or flow sensor. The assembly further includes a mating portion ( 22 ) for connection to the mask, the arrangement being such that connection of the assembly ( 20 ) to the mask ( 10 ) prevents disengagement of the interengaging connection ( 42, 44 ) between the two parts of the assembly.

1 . Patient gas delivery apparatus including a mask adapted for communication with a patient's airways, a gas flow generator and gas delivery conduit means, further including an assembly connected in series between the conduit means and the mask, said assembly being formed in at least two parts connected by interengaging connecting means, said assembly further including means for connection to the mask, wherein connection of the assembly to the mask prevents disengagement of the interengaging connecting means such that said at least two parts of the assembly cannot separate whilst the assembly is connected to the mask.  
     
     
         2 . Patient gas delivery apparatus according to  claim 1  wherein said interengaging connecting means includes detent means on a first of said parts of the assembly, said detent means releasably engaging a second of said parts of the assembly and being held in engaged position by the mask whilst the assembly is connected to the mask.  
     
     
         3 . Patient gas delivery apparatus according to  claim 2  wherein said first and second parts form a housing for a flow sensor of said apparatus.  
     
     
         4 . Patient gas delivery apparatus according to  claim 2  wherein said first and second parts form a housing for an anti-asphyxia valve member.  
     
     
         5 . Patient gas delivery apparatus according to  claim 4  wherein said housing has at least one vent which is closed by said valve member during normal operation of said apparatus, opening when pressure falls below a predetermined pressure.  
     
     
         6 . Patient gas delivery apparatus according to  claim 2  wherein said second part includes said means for connection of the assembly to the mask.  
     
     
         7 . Patient gas delivery apparatus according to  claim 6  wherein said means for connection to the mask includes a mating portion for insertion into an aperture of the mask and locking means attachable to said mating portion from an inner side of the mask so as to prevent withdrawal of the mating portion from said aperture, said detent means being prevented from disengagement from said second part whilst said mating portion is inserted in said aperture.  
     
     
         8 . Patient gas delivery apparatus according to  claim 7  wherein said detent means is prevented from said disengagement by contact with the mask.  
     
     
         9 . Patient gas delivery apparatus according to  claim 8  wherein the detent means is resiliently biased in a radial direction relative to a common axis of said aperture and said mating portion such that the detent means engages behind a respective formation on said second part and wherein opposite radial movement of said detent means to disengage from said second part is prevented by said contact.  
     
     
         10 . Patient gas delivery apparatus according to  claim 9  wherein said disengagement is prevented by a projection on the mask.  
     
     
         11 . Patient gas delivery apparatus according to  claim 10  wherein said projection includes a projecting rim surrounding said aperture.  
     
     
         12 . Patient gas delivery apparatus according to  claim 1  wherein said means for connection of the assembly to the mask includes locking means located on an inner side of said mask, such that substantial removal of the mask from the patient is a prerequisite for disconnection of the assembly from the mask and disengagement of said interengagement means.  
     
     
         13 . Patient gas delivery apparatus according to  claim 1  wherein a distal end of the assembly includes rotatable coupling means for connection of the conduit.  
     
     
         14 . Patient gas delivery apparatus according to  claim 13  wherein the mask and the conduit are not adapted for direct interconnection without the assembly.  
     
     
         15 . An assembly for connection in series between a gas delivery conduit means and a patient mask in a patient gas delivery apparatus, the assembly being formed in at least two parts connected by interengaging connecting means, said assembly further including means for connection to the mask, wherein connection of the assembly to the mask prevents disengagement of the interengaging connecting means such that said at least two parts of the assembly cannot separate whilst the assembly is connected to the mask.  
     
     
         16 . An assembly according to  claim 15 , further including an anti-asphyxia valve member housed in said assembly.  
     
     
         17 . As assembly, according to  claim 16  wherein said assembly has at least one vent, said valve member being adapted to close said vent during normal operation of the apparatus and to open when pressure falls below a predetermined pressure.