Blood treatment dialyzer/filter for permitting gas removal

Abstract

A configuration of a blood microtubular filter/dialyzer used in many kinds of renal replacement therapy systems can provide a highly effective mechanism for removing air from the blood circuit of such systems. Air is removed from an outlet header space of the filter avoiding the need for a bubble trap or settling chamber such as a drip chamber.

1 - 18 . (canceled) 
     
     
         19 . A system for removing gas from blood, the system comprising:
 a blood processing device including a microtubular fiber filter having a plurality of filter fibers with ends opening into an inlet header space and an outlet header space, the inlet header space including an inlet port and the outlet header space including an outlet port and a gas release port, the outlet port and the gas release port lying at opposite ends of the outlet header space,   the blood processing device being configured to allow blood entering through the inlet port into the inlet header space to flow through the plurality of filter fibers into the outlet header space and out the outlet port, and further configured to allow gas to collect in a portion of the inlet header space so as to be conveyed through a subset of the plurality of filter fibers into the outlet header space,   the inlet and outlet header spaces having sizes and shapes such that a shear rate of blood flow is sufficient to prevent stagnant flow regions from arising in the inlet and outlet header spaces; and   a holder configured to support said blood processing device in a position and orientation such that gas in the outlet header space accumulates in a portion of the outlet header space which is adjacent the gas release port, the gas release port being configured to periodically release the accumulated gas.   
     
     
         20 . The system of  claim 19 , wherein the filter has a longitudinal housing with a longitudinal axis and is supported by the holder so as to be at an angle with respect to the vertical. 
     
     
         21 . The system of  claim 19 , further comprising a valve connected to said gas release port and pre-connected and sterilized together with said blood processing device, the valve being configured to permit gas to egress from the outlet header space without permitting blood to egress from the outlet header space. 
     
     
         22 . The system of  claim 19 , further comprising a stopcock connected to said gas release port and pre-connected and sterilized together with said blood processing device. 
     
     
         23 . The system of  claim 19 , further comprising a syringe connected to said gas release port and pre-connected and sterilized together with said blood processing device. 
     
     
         24 . The system of  claim 19 , wherein the holder is configured to orient said blood processing device such that said outlet port is lower, with respect to a direction of gravity, than said gas release port. 
     
     
         25 . The system of  claim 19 , wherein the inlet and outlet header spaces have a hydraulic shape to eliminate stagnant flow of blood. 
     
     
         26 . The system of  claim 19 , wherein the gas release port further includes a microporous filter to prevent contamination from entering the outlet header space. 
     
     
         27 . The system of  claim 19 , wherein the portion of the inlet header space where gas collects is connected to the portion of the outlet header space where gas accumulates before release by said subset of the filter fibers. 
     
     
         28 . The system of  claim 19 , wherein the holder is configured to hold the blood processing device so that the inlet port and the outlet port are oriented below the gas release port. 
     
     
         29 . The system of  claim 19 , wherein the holder is fixedly attachable to a blood treatment machine. 
     
     
         30 . The system of  claim 19 , wherein the blood processing device is one of a blood dialyzer and a hemofilter processing element. 
     
     
         31 . The system of  claim 19 , wherein the gas release port is further configured to permit adding or removing biocompatible non-blood fluid. 
     
     
         32 . The system of  claim 19 , wherein the portion of the inlet header space where gas collects is opposite the inlet port. 
     
     
         33 . A system for processing blood, the system comprising:
 a blood processing element including filter media, the filter media being configured to convey blood and air from an inlet header chamber into an outlet header chamber through the filter media,   the blood processing element including the outlet header chamber at a position where blood and air exit said filter media, said outlet header chamber having at least one outlet; and   a holder configured to support said processing element in a preferred position and orientation, wherein the preferred position and orientation is such that air can accumulate in said outlet header chamber in a position remote from said outlet,   wherein the holder includes a flexible holding portion configured to accept the blood processing element only in the preferred position and orientation.   
     
     
         34 . A holding device for holding a blood filtering element in a preferred orientation relative to a blood processing machine, the holding device comprising:
 a flexible holding portion to receive the blood filtering element in a predetermined orientation;   an attachment portion to detachably attach the flexible holding portion to the blood processing machine, the blood processing machine including a fluid circuit,   wherein when the attachment portion is attached to the blood processing machine, the blood filtering element is positioned in a preferred orientation relative to the blood processing machine, and   wherein the preferred orientation is such that gas accumulates in a specific portion of the blood filtering element.   
     
     
         35 . The holding device of  claim 34 , wherein the blood filtering element is connected to the fluid circuit before the attachment portion is attached to the blood processing machine. 
     
     
         36 . The holding device of  claim 34 , wherein the fluid circuit includes a cartridge enclosed between two separate parts of the blood treatment machine, and the holding device is configured to be detachably attached to the cartridge so that the preferred orientation of the blood filtering element relative to the blood processing machine is determined by the attachment of the holding device to the cartridge. 
     
     
         37 . The holding device of  claim 34 , wherein the holding device is integral with the blood processing machine. 
     
     
         38 . The holding device of  claim 34 ,
 wherein,   the blood filtering element includes a microtubular fiber filter having a plurality of filter fibers with ends opening into an inlet header space and an outlet header space, the inlet header space including an inlet port and the outlet header space including an outlet port and a gas release port, the outlet port and the gas release port lying at opposite ends of the outlet header space, the blood filtering element being configured to allow blood entering through the inlet port into the inlet header space to flow through the plurality of filter fibers into the outlet header space and out the outlet port, and further configured to allow gas to collect in a portion of the inlet header space so as to be conveyed through a subset of the plurality of filter fibers into the outlet header space, the inlet and outlet header spaces having sizes and shapes such that a shear rate of blood flow is sufficient to prevent stagnant flow regions from arising in the inlet and outlet header spaces, and   the preferred orientation is such that gas accumulates in a portion of the outlet header space adjacent the gas release port.