Device for extracorporeal blood treatment

Abstract

The invention relates to a system for treating blood, which includes a single cassette capable of carrying out the various CRRT treatments.

1 . A disposable cassette for a dialysis treatment, the disposable cassette comprising a rigid body having a first fluid pathway through which a first fluid flows, and a pressure measuring zone configured to be coupled to a pressure sensor of a reusable dialysis machine wherein the disposable cassette further comprises a second fluid pathway including a first end in fluid communication with the first fluid pathway and a second end having an opening covered by a flexible membrane forming the pressure measuring zone such that the pressure measuring zone transmits the first fluid pressure to the pressure sensor while the pressure measuring zone is offset from the first fluid pathway. 
     
     
         2 . The disposable cassette as claimed in  claim 1  wherein the first fluid is a dialysate solution. 
     
     
         3 . The disposable cassette as claimed in  claim 1  wherein at least one of a length, a width or a shape of the second fluid pathway is configured in such a way as to restrict the first fluid from flowing through the second fluid pathway or from reaching the pressure measuring zone. 
     
     
         4 . The disposable cassette as claimed in  claim 1  wherein at least one of a length, a width or a shape of the second fluid pathway is configured in such a way as to trap or to keep a fluid during the treatment which is different from the first fluid. 
     
     
         5 . The disposable cassette as claimed in  claim 1  wherein the second fluid pathway includes at least one part narrower than the first fluid pathway in such a way as to restrict the first fluid from flowing through the second fluid pathway or from reaching the pressure measuring zone. 
     
     
         6 . The disposable cassette as claimed in  claim 1  wherein the second fluid pathway is configured in such a way as to limit and/or slow the progress of the first fluid during the treatment. 
     
     
         7 . The disposable cassette as claimed in  claim 1  wherein the second fluid pathway includes a second fluid which is different from the first fluid. 
     
     
         8 . The disposable cassette as claimed in  claim 7  wherein the second fluid is a gas or a compressible fluid. 
     
     
         9 . The disposable cassette as claimed in  claim 7  wherein the second fluid comprises air. 
     
     
         10 . The disposable cassette as claimed in  claim 7  wherein the disposable cassette is configured in such a way that the volume of the second fluid decreases during the treatment but retains a trapped volume of the second fluid. 
     
     
         11 . The disposable cassette as claimed in  claim 7  wherein at least one of a length, a width or a shape of the second fluid pathway depends on the expansion capacity of the second fluid and/or on the range of pressure to be measured. 
     
     
         12 . The disposable cassette as claimed in  claim 7  wherein at least one of a length, a width, or a shape of the second fluid pathway is configured to in such a way that the pressure measuring zone is filled with the first fluid and the second fluid. 
     
     
         13 . The disposable cassette as claimed in  claim 7  wherein at least one of a length, a width, or a shape of the second fluid pathway is configured to in such a way that the first fluid and the second fluid are in contact with the membrane. 
     
     
         14 . The disposable cassette as claimed in  claim 1  further including a pump for moving the first fluid through the first fluid pathway. 
     
     
         15 . The disposable cassette as claimed in  claim 14  further including damping means configured to reduce fluid pressure peak caused by the pump. 
     
     
         16 . The disposable cassette as claimed in  claim 15  wherein the damping means includes a flexible membrane. 
     
     
         17 . The disposable cassette as claimed in  claim 15  wherein the damping means includes a rigid cavity containing at least partially the second fluid.