DEVICE AND METHOD FOR DETERMINING A DIALYSIS FLUID FLOW RATE FOR EXTRACORPOREAL BLOOD TREATMENT

• US 20100042035A1
• Filed: 09/25/2007
• Published: 02/18/2010
• Est. Priority Date: 09/26/2006
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius SE & Co. KGaA)
• Original Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius SE & Co. KGaA)
• Inventors: Wüpper, Andreas, Moissl, Ulrich
• Granted Patent: US 8,512,271 B2
• Time in Patent Office: Days
• US Class Current: 604/5.40
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1613 Profiling or modelling of patient or predicted treatment evolution or outcome
• CPC Class Codes: A61M 1/1615 using measurements made at different flow rates
• CPC Class Codes: A61M 1/3607 Regulation parameters
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/50 with microprocessors or computers

Abstract

The present invention relates to a device and to a method for determining the dialysis fluid flow rate for an extracorporeal blood treatment device. The dialysis fluid flow rate Q_d is determined in accordance with the blood flow rate Q_b or the blood flow rate Q_b is determined in accordance with the dialysis fluid flow rate Q_d, wherein by increasing about a specific value, the increase of a variable characterising the efficiency of the blood treatment, in particular clearance K, does not exceed the specific value. The present invention also relates to a blood treatment device comprising a device for determining the dialysis fluid flow rate or blood flow rate and to a method for operating an extracorporeal blood treatment device. As a result, an optimal dialysis fluid flow rate and/or blood flow rate calculates the requirement in accordance with a high efficiency of the dialysis treatment and in accordance with a reduced consumption of the dialysis liquid.

Claims

1. Arrangement for presetting a dialysis-fluid rate or blood flowrate for an extra corporeal blood-treating apparatus which has a dialyser which is divided by a semi-permeable membrane into a blood chamber through which blood flows at a preset blood flowrate Q_b and a dialysis-fluid chamber through which dialysis fluid flows at a preset dialysis-fluid rate Q_d, the arrangement for presetting the dialysis-fluid rate or the blood flowrate determining the dialysis-fluid rate Q_d or blood flowrate Q_b as a function of the preset blood flowrate Q_b and dialysis-fluid rate Q_d respectively, characterised in that the arrangement for presetting the dialysis-flow rate is so arranged that what is determined at a preset blood flowrate Q_b is that dialysis-fluid rate Q_d, or what is determined at a preset dialysis-fluid rate Q_d is that blood flowrate Q_b, which, if it were increased by a given amount, would result in a metric characteristic of the effectiveness of the blood treatment increasing by not less than a given amount.

2. Arrangement according to claim 1, characterised in that the metric characteristic of the dialysis treatment is the clearance K of the dialysis treatment.

3. Arrangement according to claim 1, characterised in that the arrangement for presetting the dialysis-fluid rate or blood flowrate is so arranged that that dialysis-fluid rate Q_d or blood flowrate Q_b is determined, as a function of a metric characteristic of the dialyser, which, if it were increased by a given amount, would result in a metric characteristic of the effectiveness of the blood treatment increasing by not less than a given amount.

4. Arrangement according to claim 3, characterised in that the metric characteristic of the dialyser is the mass transfer coefficient k0A of the dialyser.

5. Arrangement according to claim 1, characterised in that the arrangement for presetting the dialysis-fluid rate or blood flowrate has an input unit (16) for presetting various modes of treatment in which the effectiveness of the blood treatment differs, there being determined, for the given mode of treatment, that dialysis-fluid rate Q_d or blood flowrate Q_b, which, if it were increased by a given amount, would result in the metric characteristic of the effectiveness of the blood treatment increasing by not less than an amount assigned to the given mode of treatment.

6. Arrangement according to claim 1, characterised in that the arrangement for presetting the dialysis-fluid rate or blood flowrate has a calculating unit (18A) which is so arranged that the dialysis-fluid rate Q_d or blood flowrate Q_b is calculated from a mathematical equation.

7. Arrangement according to claim 6, characterised in that the mathematical equation for calculating the dialysis-fluid rate Q_d is a multi-order polynomial.

8. Blood-treating apparatus for the extra-corporeal treatment of blood, having a dialyser (1) which is divided by a semi-permeable membrane (2) into a blood chamber (3) through which blood flows at a preset blood flowrate Q_b and a dialysis-fluid chamber (4) through which dialysis fluid flows at a preset dialysis-fluid rate Q_d, characterised in that the blood-treating apparatus has an arrangement (18) for presetting a dialysis-fluid rate or blood flowrate according to claim 1.

9. Blood-treating apparatus according to claim 8, characterised in that the blood-treating apparatus has a control unit (13) by which the dialysis-fluid rate Q_d or blood flowrate Q_b preset by the arrangement for presetting the dialysis-fluid rate or blood flowrate is set to.

10. Blood-treating apparatus according to claim 9, characterised in that the blood-treating apparatus has a dialysis-fluid pump (12) for pumping the dialysis-fluid at a given dialysis-fluid rate Q_d and/or a blood pump (6) for pumping blood at a given blood flowrate Q_b, the control unit (13) setting the speed of the dialysis-fluid pump or the speed of the blood pump in such a way that the dialysis fluid or the blood is pumped at the dialysis-fluid rate and blood flowrate respectively which is preset by the arrangement for presetting the dialysis-fluid rate or blood flowrate.

11. Method for presetting a dialysis-fluid rate or blood flowrate for an extra-corporeal blood-treating apparatus which has a dialyser which is divided by a semi-permeable membrane into a blood chamber through which blood flows at a preset blood flowrate Q_b and a dialysis-fluid chamber through which dialysis fluid flows at a preset dialysis-fluid rate Q_d, the dialysis-fluid rate Q_d or the blood flowrate Q_b being determined as a function of the preset blood flowrate Q_b and dialysis-fluid rate Q_d respectively, characterised in that what is determined as a function of the blood flowrate Q_b is that dialysis-fluid rate Q_d, or what is determined as a function of the dialysis-fluid rate Q_d is that blood flowrate Q_b, which, if it were increased by a given amount, would result in a metric characteristic of the effectiveness of the blood treatment increasing by not less than a given amount.

12. Method according to claim 11, characterised in that the metric characteristic of the dialysis treatment is the clearance K of the dialysis treatment.

13. Method according to claim 11, characterised in that that dialysis-fluid rate Q_d or blood flowrate Q_b is determined, as a function of a metric characteristic of the dialyser, which, if it were increased by a given amount, would result in a metric characteristic of the effectiveness of the blood treatment increasing by not less than a given amount.

14. Method according to claim 13, characterised in that the metric characteristic of the dialyser is the mass transfer coefficient k0A of the dialyser.

15. Method according to claim 11, characterised in that various modes of treatment in which the effectiveness of the blood treatment differs are preset, there being determined, for the given mode of treatment, that dialysis-fluid rate Q_d or blood flowrate Q_b which, if it were increased by a given amount, would result in a metric characteristic of the effectiveness of the blood treatment increasing by not less than an amount assigned to the given mode of treatment.

16. Method according to claim 11, characterised in that the dialysis-fluid rate Q_d or blood flowrate Q_b is calculated from a mathematical equation.

17. Method according to claim 16, characterised in that the mathematical equation for calculating the dialysis-fluid rate Q_d is a multi-order polynomial.

18. Method of operating an extra-corporeal blood-treating apparatus having a dialyser which is divided by a semi-permeable membrane into a blood chamber through which blood flows at a preset blood flowrate Q_b and a dialysis-fluid chamber through which dialysis fluid flows at a preset dialysis-fluid rate Q_d, there being set as the dialysis-fluid rate that dialysis-fluid rate, or there being set as the blood flowrate that blood flowrate, which is determined by the method according to claim 11.