Limb for breathing circuit

Abstract

A limb for a breathing circuit manufactured from very thin walled polymer materials has an elongate axial reinforcing spine lying freely inside the conduit and fixed to each end connector. The spine is laterally compliant but axially stiff. The spine provides resistance to tensile and compressive loads on the conduit, including that induced by prevailing internal pressures.

1 . (canceled) 
     
     
         2 . A limb for a breathing circuit comprising:
 a flexible conduit having a first end, a second end, and a breathing gases pathway therebetween defined by a wall, wherein the wall is formed from a helically wound membrane and a helical supporting rib;   a first connector fixed to the first end of the flexible conduit;   a second connector fixed to the second end of the flexible conduit;   an elongate reinforcing member positioned within the flexible conduit, wherein the elongate reinforcing member is connected with the first connector and the second connector; and   a sheath surrounding a portion of the flexible conduit.   
     
     
         3 . The limb of  claim 2 , wherein the sheath covers the entire length of the flexible conduit. 
     
     
         4 . The limb of  claim 2 , wherein the helically wound membrane is breathable. 
     
     
         5 . The limb of  claim 2 , wherein the helically wound membrane is sympatex. 
     
     
         6 . The limb of  claim 2 , wherein the elongate reinforcing member has a circular cross section. 
     
     
         7 . The limb of  claim 6 , wherein the elongate reinforcing member is solid. 
     
     
         8 . The limb of  claim 6 , wherein the elongate reinforcing member is hollow. 
     
     
         9 . The limb of  claim 2 , wherein the elongate reinforcing member comprises a heating element. 
     
     
         10 . The limb of  claim 9 , wherein the heating element is a positive temperature coefficient heater. 
     
     
         11 . The limb of  claim 9 , wherein the heating element is a resistance heating element. 
     
     
         12 . The limb of  claim 2 , wherein the elongate reinforcing member extends freely between the first connector and the second connector along a non-tortuous path. 
     
     
         13 . The limb of  claim 2 , wherein the elongate reinforcing member is resilient such that it does not plastically deform under normal flexing and bending of the limb. 
     
     
         14 . The limb of  claim 2 , wherein the elongate reinforcing member has a cross sectional area between 3 mm 2  and 12.5 mm 2 . 
     
     
         15 . The limb of  claim 2 , wherein the cross-sectional area of the elongate reinforcing member is less than 10% of the cross-sectional are of the flexible conduit. 
     
     
         16 . The limb of  claim 2 , wherein the sheath is braided. 
     
     
         17 . The limb of  claim 16 , wherein the braided sheath is bonded at a first end and a second end of the limb where the flexible conduit inserts into the first connector and the second connector. 
     
     
         18 . The limb of  claim 2  further comprising a heater wire. 
     
     
         19 . The limb of  claim 18 , wherein the heater wire is not associated with the elongate reinforcing member.