APPARATUS FOR EXTRACORPOREAL TREATMENT OF BLOOD

• US 20130248426A1
• Filed: 09/08/2011
• Published: 09/26/2013
• Est. Priority Date: 09/27/2010
• Status: Active Grant

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: Gambro Lundia AB (Baxter International Inc.)
• Inventors: Pouchoulin, Dominique
• Granted Patent: US 10,737,011 B2
• Time in Patent Office: Days
• US Class Current: 210/96.2
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1601 Control or regulation
• CPC Class Codes: A61M 1/1643 with weighing of fresh and used dialysis fluid
• CPC Class Codes: A61M 1/3434 with pre-dilution and post-dilution
• CPC Class Codes: A61M 1/3437 downstream of the filter, e.g. post-dilution with filtrate
• CPC Class Codes: A61M 1/3441 Substitution rate control as a function of the ultrafiltration rate
• CPC Class Codes: A61M 1/3451 the difference in weight between both ultra-filtrate and substitution reservoir being used as control signal
• CPC Class Codes: A61M 1/3663 Flow rate transducers; Flow integrators
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/3393 by weighing the reservoir
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/505 Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches

Abstract

An apparatus for extracorporeal treatment of blood including a filtration unit, a blood withdrawal line, a blood return line, an effluent fluid line, a dilution fluid line connected to the blood withdrawal line, and a dialysis fluid line. Pumps act on the fluid lines for regulating the flow of fluid. A control unit sets initial values for a fluid flow rate(s) through the lines and periodically executes a flow rate update procedure to adjust the fluid flow rate(s) to deliver a set dose (Dset) in a reference time interval.

Claims

1-19. -19. (canceled)

20. An apparatus for extracorporeal treatment of blood comprising:

a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane;

a blood withdrawal line connected to an inlet of the primary chamber, and a blood return line connected to an outlet of the primary chamber said blood lines being designed to be connected to a cardiovascular system of a human patient;

a blood pump configured to control blood flow through the blood lines;

an effluent fluid line connected to an outlet of the secondary chamber;

at least one fluid line selected from a group comprising one or more infusion fluid lines connected to one of the blood withdrawal line and the blood return line, and a dialysis fluid line connected to the inlet of the secondary chamber;

at least one pump configured to control fluid flowing through at least one of the effluent fluid line and the at least one fluid line; and

a control unit including a processor and a non-transitory memory storing instructions to be executed by the processor and cause the control unit to;

set initial values to one or more fluid flow rates selected from a group including a fluid flow rate (Q_eff) through the effluent line, a fluid flow rate (Q_rep or Q_pbp) through the one or more infusion fluid lines, a fluid flow rate (Q_dial) through the dialysis liquid fluid line, and a fluid removal rate (Q_pfr) from the patient,

determine a prescribed dose (D_set) as a target mean value of a flow rate through the at least one fluid line during a patient treatment,

execute a flow rate update procedure comprising calculating an updated set of values for one or more of said fluid flow rates based on said prescribed dose (D_set) to deliver the prescribed dose (D_set) during a reference time interval, and

control the at least one pump to control the fluid flow based on said updated set values.

21. The apparatus of claim 20, wherein said prescribed dose (D_set) comprises a prescribed value for one flow rate selected from a group comprising:

an effluent dose flow rate (D<sub>eff—

set</sub>) which is a prescribed mean value of the flow rate through the effluent line,

a convective dose flow rate (D<sub>conv—

set</sub>) which is a prescribed mean value of a sum of at least one of the flow rates (Q_rep, Q_pbp) and the fluid removal rate (Q_pfr),

a diffusive dose flow rate (D<sub>dial—

set</sub>) which is a prescribed mean value of the flow rate (Q_dial) through the dialysis fluid line,

a urea dose (D<sub>urea—

set</sub>) which is a prescribed mean value for an estimated urea clearance, and

a clearance dose (K<sub>solute—

set</sub>) which is a prescribed mean value for an estimated clearance for a solute.

22. The apparatus of claim 21, wherein the control unit executes said flow update procedure at check points (Ti) during a treatment of a patient.

23. The apparatus of claim 22 wherein the control unit executes said flow update procedure which further comprises:

determining a value of a dose delivered (D_del) over a time interval (T_retro) preceding one of the check points (T_i);

determining a dose need value (D_need) corresponding to the one of the check points (T_i) and based at least on the dose delivered value (D_del) and the prescribed dose value (D_set);

calculating the updated set of values for said fluid flow rates based on said dose need value (D_need).

24. The apparatus according to claim 23 wherein the control unit executes said flow update procedure in which the determining a dose need value (D_need) comprises computing the dose needed to be delivered over a next time period (T_prosp) following the check point (T_i) to reach a prescribed dose over a reference time interval determined as a sum of the time interval (T_retro) and a next time period (T_prosp).

25. The apparatus according to claim 24 wherein the dose need value (D_need) is calculated according to the formula:

26. The apparatus according to claim 24 wherein, the instructions executed by the processor cause the control unit to determine an effective portion (T_eff) of said next time period (T_prosp) and a corrected dose value (D_computed) is calculated as follows:

27. The apparatus according to claim 26 wherein, the instructions executed by the processor cause the control unit to account for said effective portion (T_eff) to be expected over the next time period (T_prosp) by calculating an updated set of values for said fluid flow rates based on said corrected dose value (D_computed).

28. The apparatus of claim 20, further comprising a user interface connected to said control unit, wherein the instructions executed by the processor cause the control unit control unit to:

display on the user interface an indicium prompting a user to select whether to enter in a dose control mode, and

execute said flow rate update procedure in response to a user selection of the dose control mode.

29. The apparatus of claim 28, wherein the instructions executed by the processor cause the control unit control unit to:

display on the user interface an indicium prompting a user to enter said initial set values of said fluid flow rates,

receive said initial set values,

detect if the user selects said dose control mode, and

if the user selects to enter in the dose control mode, calculate the prescribed dose based on said initial set values.

30. The apparatus of claim 29 wherein the instructions executed by the processor cause the control unit control unit:

in response to the user selecting to enter in the dose control mode, display an indicium prompting a user to enter the prescribed dose, and

calculate said initial values of said flow rates based on said prescribed dose.

31. The apparatus of claim 20, wherein the control unit executes said flow update procedure which further comprises:

displaying on a user interface said calculated updated set of values for said flow rates,

prompting user to confirm said updated set of values for said flow rates, and

in response to the user confirming said updated set of values, controlling said at least one pump based on said updated set of values for said flow rates.

32. The apparatus of claim 20, wherein the control unit in response to the execution of the instructions by the processor:

starts a treatment by controlling said means at least one pump based on said initial set of flow rates;

after a triggering event, performing said flow rate update procedure, wherein said triggering event is at least one of a group of events including;

expiration of a prefixed time period, a change in the value set for the prescribed dose (D_set), a change in blood pump flow rate beyond a prefixed threshold, and an occurrence of a recirculation of blood beyond a prefixed threshold between the blood return line and the blood withdrawal line.

33. The apparatus of claim 32, wherein the control unit in response to the execution of the instructions by the processor further executes said flow update procedure before starting the treatment.

34. The apparatus of claim 20 wherein:

said one or more infusion fluid lines comprise a pre-dilution fluid line connected to the blood withdrawal line or a post-dilution fluid line connected to the blood return line, and

the at least one pump includes a pre-dilution pump configured to control flow through said pre-dilution fluid line and a post-dilution pump configured to control flow through said post-dilution fluid line.

35. The apparatus of claim 20 wherein:

said one or more infusion fluid lines comprise a pre-blood pump infusion line connected to the blood withdrawal line upstream the blood pump, and

the at least one pump includes a pre-dilution pump comprises a pre-blood infusion pump configured to control flow through said pre-blood pump infusion line.

36. The apparatus according claim 20 wherein the control unit in response to the execution of the instructions by the processor updates the fluid flow rate (Q_rep or Q_pbp) and updates the fluid flow rate (Q_dial) through the dialysis pump fluid line, wherein the updated fluid flow rate (Q_rep or Q_pbp) and the updated fluid flow rate (Q_dial) differ from respective initial values by a same percentage.

37. The apparatus according claim 20 wherein the control unit in response to the execution of the instructions by the processor updates at least one of the fluid flow rate (Q_rep or Q_pbp) and the fluid flow rate (Q_dial) through the dialysis pump fluid line.

38. The apparatus according claim 20 wherein the control unit in response to the execution of the instructions by the processor updates the fluid flow rate (Q_pbp) through a one of the infusion fluid lines connected to the blood withdrawal line downstream of the blood pump, and updates the fluid flow rate (Q_rep) through a one of the infusion fluid lines connected to the blood withdrawal line downstream for the blood pump.

39. The apparatus according to claim 38, wherein the fluid flow rate (Q_pbp) remains constant while the update changes the fluid flow rate (Q_rep).

40. The apparatus according to claim 39, wherein the fluid removal rate (Q_pfr) remains constant while the update changes the fluid flow rate (Q_rep).

41. The apparatus according to claim 38 wherein the control unit in response to the execution of the instructions cause the blood pump to maintain a constant flow of blood through the blood lines while updating the fluid flow rate (Q_pbp) and the fluid flow rate (Q_rep).

42. The apparatus according to claim 20, wherein the control unit in response to the execution of the instructions:

prompts a user to select whether to enter in a dose control mode,

prompts a user to select a treatment mode,

determines whether the selected treatment mode and selected the dose control mode conflict, and

prevents the dose control mode when a conflict is determined.

43. The apparatus of claim 20, wherein the control unit in response to the execution of the instructions:

determines a first value for the prescribed dose (D_set) to be achieved during a patient treatment period;

modifies the first value to a second value, different from the first value, of the prescribed dose (D_set), and

calculates the updated set of values for one or more of said fluid flow rates based upon the first value, the second value, a timing of said second value and a reference time interval within the patient treatment period.

44. An extracorporeal treatment system including:

a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane;

a blood withdrawal line connected to an inlet of the primary chamber and a blood return line connected to an outlet of the primary chamber, wherein said blood withdrawal and return lines are configured to be in fluid communication with a cardiovascular system of a human patient;

a blood pump configured to pump blood through the blood withdrawal line an the blood return line;

an effluent fluid line connected to an outlet of the secondary chamber;

at least one fluid line from a group comprising;

one or more infusion fluid lines connected to one of the blood withdrawal line and the blood return line, and a dialysis fluid line connected to the inlet of the secondary chamber;

at least one pump configured to pump fluid through the at least one fluid line, and a control unit including a processor and a non-transitory memory storing instructions which when executed by the processor cause the control unit to;

set an initial value for each of one or more fluid flow rates selected in the group including an effluent fluid flow rate (Q_eff) through the effluent line, an infusion fluid flow rate (Q_rep or Q_pbp) through the one or more infusion fluid lines, a dialysis fluid flow rate (Q_dial) through the dialysis liquid fluid line, and a fluid removal rate (Q_pfr);

receive or determine a prescribed dose (D_set) to pass through the effluent line,

calculate an updated value set of the initial value set for one or more of said fluid flow rates based on said prescribed dose (D_set), such that said flow rate through the effluent line corresponds to delivering the prescribed dose (D_set) occurs during reference periods within the treatment of the patient,

control fluid flow through the one or more infusion fluid lines based on the updated value set;

repeat the calculation of the updated value set at each of check timing points (Ti) during the treatment,

wherein the calculation of the updated value set at each of the check timing points includes;

determining a value of the dose delivered (D_del) over a time interval (T_retro) preceding a most recent one of the check points (T_i);

determining a dose need value (D_need) based on the dose delivered and on the prescribed dose (D_set), and

calculating the updated set of values for said fluid flow rates based on said dose need value.

45. The system of claim 44, wherein the control unit determines an effective portion (T_eff) of a time period following the one of the check points, wherein the effective portion (T_eff) corresponds to a period during which blood is returned to the patient.

46. The system of claim 44 wherein said flow rate update procedure comprises:

displaying on a user interface the updated set of values,

prompting the user to confirm said updated set of values,

in response to the user confirming the updated set of flow rate values, controlling the flow rates based on said updated set of values.