Device and method for controlling an extracorporeal blood- treating apparatus

A system for controlling a hemodialysis apparatus, comprising:

• a dialyzer divided by a semi-permeable membrane into a blood chamber and a dialysis fluid chamber;
• a blood pump for pumping blood through the blood chamber at a blood flowrate Qb;
• a dialysis fluid pump for pumping dialysis fluid through the dialysis fluid chamber at a dialysis fluid flowrate Qd;
• a memory unit for storing a desired clearance K or dialysance D;
• and
• a control unit for setting the blood pump to a blood flowrate Qb and setting the dialysis fluid pump to a dialysis fluid flowrate Qd, the control unit comprising:
• a calculating unit configured to receive an initial blood flowrate Qb, and a desired clearance K or dialysance D, and calculate the dialysis fluid flowrate Qd to be set therefrom, or to receive an initial dialysis fluid flowrate Qd, and a desired clearance or dialysance, and calculate the blood flowrate Qb to be set therefrom.

A system for controlling an extracorporeal blood-treating apparatus comprising:

• an exchanging unit divided by a semi-permeable membrane into a first chamber and a second chamber, wherein the first chamber is part of an extracorporeal blood circuit comprising a blood pump for pumping blood at a blood flowrate Qb, and the second chamber is part of a dialysis circuit comprising a dialysis pump for pumping dialysis fluid at a dialysis fluid flowrate Qd;
• at least one of a substituent inlet line for feeding substituent directly to the extracorporeal blood circuit having a substituent flowrate Qs, and an ultrafiltrate outlet line from the first chamber having a flowrate that corresponds to the sum of the substituent flowrate Qs and an ultrafiltration flowrate Qf;
• a memory unit for storing a desired clearance K or dialysance D;
• and
• a control unit for setting the blood pump to a blood flowrate Qb and for setting at least one of the dialysis fluid flowrate Qd, the ultrafiltration flowrate Qf, or the substituent flowrate Qs, the control unit comprising:
• a calculating unit configured to receive a desired clearance K or dialysance D and at least one first flowrate chosen from the group consisting of:
• blood flowrate Qb, dialysis fluid flowrate Qd, ultrafiltrate flowrate Qf, and substituent flowrate Qs, and calculate at least one second flowrate from one of the other flowrates chosen from the group consisting of:
• blood flowrate Qb, dialysis fluid flowrate Qd, ultrafiltrate flowrate Qf, and substituent flowrate Qs, wherein the desired clearance K or dialysance D is maintained.

A method of controlling an extra-corporeal blood-treating apparatus, the extra-corporeal blood-treating apparatus comprising:

• an exchanging unit divided by a semi-permeable membrane into a first chamber and a second chamber, wherein the first chamber is part of an extracorporeal blood circuit comprising a blood pump for pumping blood at a blood flowrate Qb, and the second chamber is part of a dialysis circuit comprising a dialysis pump for pumping dialysis fluid at a dialysis fluid flowrate Qd;
• at least one of a substituent inlet line for feeding substituent directly to the extracorporeal blood circuit having a substituent flowrate Qs;
• and an ultrafiltrate outlet line from the first chamber having a flowrate that corresponds to the sum of the substituent flowrate Qs and an ultrafiltration flowrate Qf;
• the method comprising the following steps:
• storing a desired clearance K or dialysance D,
• setting at least one first flowrate chosen from the group consisting of blood flowrate Qb, dialysis fluid flowrate Qd, ultrafiltrate flowrate Qf and substituent flowrate Qs;
• and
• calculating at least one second flowrate of one of the other flowrates chosen from the group consisting of:
• blood flowrate Qb, dialysis fluid flowrate Qd, ultrafiltrate flowrate Qf and substituent flowrate Qs.

A method of controlling a hemodialysis apparatus, the hemodialysis apparatus comprising:

• a dialyzer divided by a semi-permeable membrane into a blood chamber and a dialysis fluid chamber;
• a blood pump for pumping blood through the blood chamber at a blood flowrate Qb;
• a dialysis fluid pump for pumping dialysis fluid through the dialysis fluid chamber at a dialysis fluid flowrate Qd;
• the method comprising the following steps:
• storing a desired clearance K or dialysance D;
• and
• for an initial blood flowrate Qb and the desired clearance K or dialysance D, calculating the dialysis fluid flowrate Qd to be set;
• or
• for an initial dialysis fluid flowrate Qd and the desired clearance K or dialysance D, calculating the blood flowrate Qb to be set.