Dialysis cassettes and related systems and methods

Abstract

A method that includes conveying overheated dialysate through a cassette in a manner to reduce the temperature of the overheated dialysate, and a dialysis system including a control unit configured to cause overheated dialysate to be conveyed through a cassette in a manner to reduce the temperature of the overheated dialysate.

1 . A method of controlling the temperature of liquid in a dialysis cassette, the method comprising:
 pumping liquid heated to a temperature greater than a desired temperature from a first pump chamber of the dialysis cassette to a second pump chamber of the dialysis cassette.   
   
   
       2 . The method of  claim 1 , further comprising pumping the liquid from the second pump chamber of the dialysis cassette back to the first pump chamber of the dialysis cassette. 
   
   
       3 . The method of  claim 2 , wherein the liquid is pumped back and forth between the first and second pump chambers of the dialysis cassette until the liquid reaches the desired temperature. 
   
   
       4 . The method of  claim 1 , further comprising turning off a heating device configured to heat the liquid in the dialysis cassette, and closing an outlet passage formed in the cassette such that the liquid is substantially prevented from exiting the cassette via the outlet passage. 
   
   
       5 . The method of  claim 4 , wherein a fluid line is connected to the outlet passage and to a patient, and closing the outlet passage substantially prevents the liquid from being delivered via the fluid line to the patient. 
   
   
       6 . The method of  claim 1 , wherein unheated liquid is present in the second pump chamber when the liquid heated to a temperature greater than the desired temperature is pumped into the second pump chamber. 
   
   
       7 . The method of  claim 6 , wherein, when a mixture of the unheated liquid and the liquid heated to a temperature greater than the desired temperature in the second pump chamber is below a given temperature, the mixture is conveyed from the second pump chamber to an outlet passage, then to a heating region of the cassette, then to the first pump chamber. 
   
   
       8 . The method of  claim 6 , wherein, when a mixture of the unheated liquid and the liquid heated to a temperature greater than the desired temperature in the second pump chamber is above a given temperature, the mixture is conveyed from the second pump chamber to a heating region of the cassette, then to an outlet passage, then to the first pump chamber. 
   
   
       9 . The method of  claim 1 , further comprising sensing the temperature of liquid in the cassette. 
   
   
       10 . The method of  claim 9 , wherein the temperature of liquid in a heating region of the cassette is sensed. 
   
   
       11 . The method of  claim 9 , wherein the temperature of liquid in the first pump chamber of the cassette and the temperature of liquid in the second pump chamber of the cassette is sensed. 
   
   
       12 . A dialysis system, comprising:
 a dialysis cassette comprising
 a first pump chamber; 
 a second pump chamber; and 
 a heating region comprising a fluid passage that can be placed in fluid communication with the first pump chamber and the second pump chamber; and 
   a dialysis machine configured to retain the dialysis cassette, the dialysis machine comprising
 a first pump configured to cooperate with the first pump chamber to pump liquid out of the first pump chamber when the dialysis cassette is retained by the dialysis machine; 
 a second pump configured to cooperate with the second pump chamber to pump liquid out of the second pump chamber when the dialysis cassette is retained by the dialysis machine; and 
 a control unit configured to pump liquid heated to a temperature greater than a desired temperature from the first pump chamber of the dialysis cassette to the second pump chamber of the dialysis cassette when the dialysis cassette is retained by the dialysis machine. 
   
   
   
       13 . The dialysis system of  claim 12 , wherein the dialysis machine further comprises a heating device configured to heat liquid flowing through the passage of the heating region of the cassette when the dialysis cassette is retained by the dialysis machine. 
   
   
       14 . The dialysis system of  claim 12 , further comprising at least one temperature sensor configured to measure the temperature of liquid in the cassette. 
   
   
       15 . The dialysis system of  claim 12 , wherein the control unit is configured to cause the liquid to be pumped back and forth between the first and second pump chambers of the dialysis cassette until the liquid reaches the desired temperature. 
   
   
       16 . The dialysis system of  claim 12 , wherein the control unit is configured to turn off a heating device configured to heat the liquid in the dialysis cassette, and the control unit is configured to cause an outlet passage formed in the cassette to be closed such that the liquid is substantially prevented from exiting the cassette via the outlet passage. 
   
   
       17 . The dialysis system of  claim 16 , wherein a fluid line is connected to the outlet passage and to a patient, and closing the outlet passage substantially prevents the liquid from being delivered via the fluid line to the patient. 
   
   
       18 . The dialysis system of  claim 12 , wherein the dialysis cassette further comprises an outlet passage that can be placed in fluid communication with the first pump chamber, the second pump chamber, and the fluid passage in the heating region of the dialysis cassette. 
   
   
       19 . The dialysis system of  claim 18 , wherein the control unit is configured such that when a mixture of unheated liquid and the liquid heated to a temperature greater than the desired temperature in the second pump chamber is below a given temperature, the control unit causes the mixture to be conveyed from the second pump chamber to the outlet passage, then to the heating region of the cassette, then to the first pump chamber. 
   
   
       20 . The dialysis system of  claim 18 , wherein the control unit is configured such that when a mixture of the unheated liquid and the liquid heated to a temperature greater than the desired temperature in the second pump chamber is above a given temperature, the control unit causes the mixture to be conveyed from the second pump chamber to the heating region of the cassette, then to the outlet passage, then to the first pump chamber.