Blood treatment dialyzer/filter design to trap entrained air in a fluid circuit

Abstract

A modification in the configuration of the blood microtubular filter/dializer used in many kinds of renal replacement therapy systems can provide highly a effective mechanism for removing air from the blood circuit of such systems. In embodiments, for example, the invention takes advantage of the slow flow rate that usually occurs where blood exits the microtubules into a header area of the filter to provide a settling area and, preferably, a air relief mechanism.

1 . A blood treatment apparatus, comprising:
 a blood processing element including filter media through which blood passes;   
       said processing element having a header chamber at a position where blood exits a portion of said blood processing element, said header chamber having at least one outlet;
 a holder configured to support said processing element in a position and orientation such that air can accumulate in said header chamber in a position remote from said outlet whereby said header chamber is enabled to remove air from blood. 
 
     
     
         2 . Apparatus as in  claim 1 , wherein said processing element is attached to a fluid circuit and forms a part of a disposable set. 
     
     
         3 . Apparatus as in  claim 1 , wherein said holder is fixedly attachable to a blood treatment machine. 
     
     
         4 . Apparatus as in  claim 1 , wherein said holder is configured to support said filter at an angle with respect to the vertical, as defined with respect to the force of gravity. 
     
     
         5 . Apparatus as in  claim 1 , wherein said processing element includes tubular membrane media that are vertically oriented in ordinary use. 
     
     
         6 . A blood treatment apparatus, comprising:
 a blood dialyzer or hemofilter processing element including filter media through which blood passes;   said processing element having a header chamber at a position where blood exits a treatment portion of said blood processing element, said header chamber having at least one blood outlet and at least one auxiliary outlet;   a holder configured to support said dialyzer or hemofilter in a position and orientation such that air can accumulate in said header chamber in a position in said header space that is adjacent and in communication with said auxiliary outlet.   
     
     
         7 . Apparatus as in  claim 6 , wherein said auxiliary outlet is remote from said blood outlet. 
     
     
         8 . Apparatus as in  claim 6 , wherein said auxiliary outlet is opposite said blood outlet. 
     
     
         9 . Apparatus as in  claim 6 , further comprising a valve connected to said auxiliary port and pre-connected and sterilized together with said blood processing element. 
     
     
         10 . Apparatus as in  claim 6 , further comprising a stopcock connected to said auxiliary port and pre-connected and sterilized together with said blood processing element. 
     
     
         11 . Apparatus as in  claim 6 , further comprising a syringe connected to said auxiliary port and pre-connected and sterilized together with said blood processing element. 
     
     
         12 . Apparatus as in  claim 6 , further comprising a holder configured to orient said blood processing element such that said at least one blood outlet is lower, with respect to a direction of gravity, than said auxiliary outlet. 
     
     
         13 . Apparatus as in  claim 6 , further comprising an gas release component connected to said auxiliary port and pre-connected and sterilized together with said blood processing element, said air release component being configured to permit gas to egress from said header space without permitting blood to egress from said header space. 
     
     
         14 . Apparatus as in  claim 13 , wherein said air release component includes a hydrophobic membrane. 
     
     
         15 . A blood treatment apparatus, comprising:
 a blood dialyzer or hemofilter processing element including filter media through which blood passes;   
       said processing element having a chamber at an exit of a treatment portion thereof where blood flow velocity drops to a low rate, said chamber having at least one outlet;
 a holder attachable to a blood treatment machine and configurable to support said processing element in a position and orientation such that air can accumulate in said header chamber in a position remote from said outlet whereby said header chamber is enabled to remove air from blood. 
 
     
     
         16 . Apparatus as in  claim 15 , wherein said processing element is attached to a fluid circuit and forms a part of a disposable set. 
     
     
         17 . Apparatus as in  claim 16 , wherein said holder is configured to support said filter at an angle with respect to the vertical, as defined with respect to the force of gravity. 
     
     
         18 . Apparatus as in  claim 15 , wherein said holder is configured to support said filter at an angle with respect to the vertical, as defined with respect to the force of gravity. 
     
     
         19 . Apparatus as in  claim 15 , wherein said processing element includes tubular membrane media that are vertically oriented in ordinary use. 
     
     
         20 . A blood treatment apparatus, comprising:
 a blood processing element including filter media through which blood passes;   
       said processing element having a header chamber at a position where blood exits a portion of said blood processing element, said header chamber having at least one blood outlet and one auxiliary outlet;
 said auxiliary outlet being configured to permit the removal of air accumulated in said header chamber and/or addition and removal of biocompatible non-blood fluid. 
 
     
     
         21 . Apparatus as in  claim 20 , further comprising a valve connected to said auxiliary port and pre-connected and sterilized together with said blood processing element. 
     
     
         22 . Apparatus as in  claim 20 , further comprising a stopcock connected to said auxiliary port and pre-connected and sterilized together with said blood processing element. 
     
     
         23 . Apparatus as in  claim 20 , further comprising a syringe connected to said auxiliary port and pre-connected and sterilized together with said blood processing element. 
     
     
         24 . Apparatus as in  claim 20 , further comprising a holder configured to orient said blood processing element such that said at least one blood outlet is lower, with respect to a direction of gravity, than said auxiliary outlet. 
     
     
         25 . Apparatus as in  claim 20 , further comprising an gas release component connected to said auxiliary port and pre-connected and sterilized together with said blood processing element, said air release component being configured to permit gas to egress from said header space without permitting blood to egress from said header space. 
     
     
         26 . Apparatus as in  claim 25 , wherein said air release component includes a hydrophobic membrane.