Waste balancing for extracorporeal blood treatment systems

Abstract

One or more waste balancing systems may be used in a fluid circulating system for medical use. The fluid circulating system may be part of a blood treatment system for a patient suffering renal failure. A waste balancing system may include a pressure element operable to maintain a constant fluid pressure created by the combined weight of waste removed from a patient and replacement fluid for providing to a patient. Multiple evaluation characteristics or control parameters may be evaluated or controlled for safety and accuracy. At least part of the waste balancing system may be incorporated into a disposable cartridge.

1 - 20 . (canceled) 
     
     
         21 . A waste balancing system for an extracorporeal blood treatment system, the waste balancing system including:
 a container;   a flexible replacement fluid receptacle disposed in the container, the replacement fluid receptacle having an outlet connected to a replacement fluid line that is configured to convey replacement fluid to a patient during a blood treatment performed by the extracorporeal blood treatment system;   a flexible waste fluid receptacle disposed in the container atop the replacement fluid receptacle such that the waste fluid receptacle exerts a pressure on the replacement fluid receptacle based on the weight of waste fluid contained in the waste fluid receptacle; and   a pressure element in contact with the replacement fluid line proximal to said outlet,   wherein the pressure element is configured to apply a pressure to the replacement fluid line such that when a combined height of the replacement fluid and waste fluid receptacles exceeds a predetermined threshold, replacement fluid is allowed to flow through the replacement fluid line, and   when the combined height of the replacement fluid and waste fluid receptacles is less than a predetermined threshold, the pressure element clamps the replacement fluid line to prevent flow therethrough.   
     
     
         22 . The waste balancing system of  claim 21 , further comprising a waste fluid line connected to the waste fluid receptacle, the waste fluid line being configured to convey waste fluid generated by the blood treatment performed by the extracorporeal blood treatment system. 
     
     
         23 . The waste balancing system of  claim 21 , wherein the pressure element includes a pressure body in contact with a surface of the replacement fluid line, which is a flexible conduit. 
     
     
         24 . The waste balancing system of  claim 23 , wherein the pressure element further includes a pressure bag and a pressure conduit fluidically connecting the pressure bag with the pressure body, the pressure bag being filled with a fluid, and a height of the pressure bag determines the pressure applied to the replacement fluid line by the pressure body. 
     
     
         25 . The waste balancing system of  claim 23 , wherein the pressure element further includes a pressure bag and a pressure conduit fluidically connecting the pressure bag with the pressure body, the pressure bag being filled with a fluid, and an amount of the fluid determines the pressure applied to the replacement fluid line by the pressure body. 
     
     
         26 . The waste balancing system of  claim 21 , wherein the replacement fluid receptacle and the flexible waste receptacle each comprise a flexible bag. 
     
     
         27 . A method of waste balancing in an extracorporeal blood treatment, the method comprising:
 inserting a sealed flexible bag of replacement fluid into a balancing container;   connecting an outlet of the replacement fluid bag to a replacement fluid line, which is configured to convey replacement fluid to a patient during the blood treatment;   applying a first pressure to the replacement fluid line using a pressure element in contact with the replacement fluid line at a location proximal to said outlet;   gradually reducing the pressure applied by said pressure element until flow through the replacement fluid line initiates at a second pressure;   providing a flexible bag for waste fluid atop the replacement fluid bag in the balancing container; and   while maintaining the second pressure on the replacement fluid line by the pressure element, flowing waste fluid into the waste fluid bag, the flow of replacement fluid through the replacement fluid line being regulated by said second pressure.   
     
     
         28 . The waste balancing method of  claim 27 , wherein an amount of waste fluid flowing into the waste fluid bag is equivalent to an amount of replacement fluid flowing through the replacement fluid line. 
     
     
         29 . The waste balancing method of  claim 27 , wherein the replacement fluid line is a flexible contact and the pressure element includes:
 a pressure body in contact with a surface of the replacement fluid line;   a pressure bag filled with a fluid; and   a pressure conduit fluidically connecting the pressure bag with the pressure body.   
     
     
         30 . The waste balancing method of  claim 29 , wherein the amount of pressure applied the pressure body to the replacement fluid line is determined by one of the height of the pressure bag and the amount of fluid in the pressure bag. 
     
     
         31 . The waste balancing method of  claim 30 , wherein the gradually reducing the pressure applied includes reducing the height of the pressure bag and/or reducing the amount of fluid in the pressure bag. 
     
     
         32 . The waste balancing method of  claim 30 , wherein the maintaining the second pressure on the replacement fluid line includes maintaining the height of the pressure bag and keeping the amount of fluid in the pressure bag constant.