Apparatus for extracorporeal treatment of blood and process of calculating set flow rates in a medical apparatus for delivery or collection of fluids

• US 10,052,423 B2
• Filed: 08/23/2012
• Issued: 08/21/2018
• Est. Priority Date: 08/30/2011
• Status: Active Grant

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: Gambro Lundia AB (Baxter International Inc.)
• Inventors: Pouchoulin, Dominique
• Primary Examiner(s): Menon, Krishnan S
• Assistant Examiner(s): Huang, Ryan B
• Application Number:
  US14/342,025
• Publication Number:
  US 20150034557A1
• Time in Patent Office: 2,189 Days
• Field of Search: None
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1601 Control or regulation
• CPC Class Codes: A61M 1/1605 Physical characteristics of the dialysate fluid
• CPC Class Codes: A61M 1/1613 Profiling or modelling of patient or predicted treatment evolution or outcome
• CPC Class Codes: A61M 1/34 Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration
• CPC Class Codes: A61M 1/3403 Regulation parameters
• CPC Class Codes: A61M 1/3406 Physical characteristics of the filtrate, e.g. urea
• CPC Class Codes: A61M 1/341 by measuring the filtrate rate or volume
• CPC Class Codes: A61M 1/342 Adding solutions to the blood, e.g. substitution solutions for preventing coagulation A61M1/3672
• 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 1/3607 Regulation parameters
• CPC Class Codes: A61M 1/3609 Physical characteristics of the blood, e.g. haematocrit, urea
• CPC Class Codes: A61M 1/3675 Deactivation
• CPC Class Codes: A61M 2202/0413 Blood
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/3393 by weighing the reservoir
• CPC Class Codes: A61M 2205/502 : User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/52 : with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2205/75 : with filters
• CPC Class Codes: G01F 1/00 : Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow measuring a proportion of the volume flow G01F5/00
• CPC Class Codes: G16H 20/17 : delivered via infusion or injection
• CPC Class Codes: G16H 20/30 : relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising
• CPC Class Codes: G16Z 99/00 : Subject matter not provided for in other main groups of this subclass

Abstract

An apparatus for extracorporeal treatment of fluid and a process of setting up a medical apparatus for the delivery or collection of fluids are disclosed. According to the apparatus and the process, a control unit (10) is configured calculate set values of two or more of the fluid flow rates based on a fluid flow rate set by the operator and on a prescribed dose value (D_set).

Claims

1. 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 configured for connection to a patient cardiovascular system;

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

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

at least two further fluid lines selected in the group comprising;

a pre-dilution infusion fluid line connected at one end thereof to the blood withdrawal line,

a post-dilution infusion fluid line connected at one end thereof to the blood return line,

a dialysis fluid line connected at one end thereof to the inlet of the secondary chamber,

a pre-blood pump infusion fluid line connected at one end thereof to the blood withdrawal line in a region positioned in use upstream the blood pump,

at least one solution pump configured to regulate the flow of fluid through said fluid lines; and

a control unit comprising a memory and connected operably to the at least one solution pump, the control unit being configured to;

enter a set value by an operator for at least a first fluid flow rate selected in the group including;

a fluid flow rate (Q_rep1) through the pre-dilution infusion fluid line,

a fluid flow rate (Q_rep2) through the post-dilution infusion fluid line,

a fluid flow rate (Q_pbp) through the pre-blood pump infusion fluid line,

a fluid flow rate (Q_dial) through the dialysis fluid line, and

a fluid removal rate (Q_pfr) from the patient,

enter a set value by the operator for a prescribed dose (D_set) to be delivered,

calculate set values of at least a second and a third of the fluid flow rates of said group of flow rates by applying said prescribed dose value (D_set) and the set value of the first fluid flow rate to a plurality of mathematical relations, wherein said plurality of mathematical relations stored in said memory comprise one or more of the following;

a convection-diffusion relation, relating the total fluid flow rate through said infusion fluid lines (Q_rep1+Q_rep2+Q_pbp) with the fluid flow rate through said dialysis fluid line (Q_dial), or

a pre-post relation, relating the fluid flow rates (Q_rep1+Q_pbp) through pre-dilution infusion fluid line and pre-blood pump infusion fluid line with the fluid flow rate through the post-dilution infusion fluid line (Q_rep2), and

wherein calculating the set values of the at least second and third of the fluid flow rates reduces a number of flow rate set values entered into the control unit by the operator.

2. Apparatus according to claim 1, wherein the control unit is further configured to control said at least one solution pump based on said set values of the fluid flow rates.

3. An apparatus according to claim 1,

wherein said plurality of mathematical relations stored in said memory further comprise:

a blood pre-dilution relation, relating the flow rate of blood or of plasma (Q_BLOOD;

Q_PLASMA) and the fluid flow rate infused in the blood withdrawal line (Q_rep1+Q_pbp) through said pre-dilution infusion fluid line and through said pre-blood pump infusion fluid line.

4. Apparatus according to claim 1, wherein the control unit is further configured to allow the user to select at least two of said relations and to calculate the set values of at least the second and third of said fluid flow rates by applying the set value of the prescribed dose and the set value of the first fluid flow rate entered by the operator to the mathematical relations selected by the user.

5. Apparatus according to claim 3, wherein

the convection-diffusion relation defines a first ratio (R₁) dividing the total fluid flow rate (Q_rep1+Q_rep2+Q_pbp) through said infusion fluid lines by the fluid flow rate (Q_dial) through said dialysis fluid line,

the blood pre-dilution relation defines a second ratio (R₂) dividing the flow rate of blood or of plasma (Q_BLOOD;

Q_PLASMA) by the sum of fluid flow rates (Q_rep1+Q_pbp) infused in the blood withdrawal line through said pre-dilution infusion fluid line and through said pre-blood pump infusion fluid line,

the pre-post relation defines a third ratio (R₃) dividing the sum of the fluid flow rates (Q_rep1+Q_pbp) through said pre-blood pump infusion fluid line and pre-dilution infusion fluid line by the fluid flow rate (Q_rep2) through said post-dilution infusion fluid line.

6. Apparatus according to claim 5 wherein the control unit is further configured to store a preset value or a preset range for each one of said first, second and third ratios (R₁, R₂, R₃), or allow entry by an operator of a set value or a set range for each one of said first, second and third ratios (R₁, R₂, R₃).

7. The apparatus according to claim 1, wherein the blood pump is active in correspondence of a segment of the blood withdrawal line and wherein the apparatus comprises the following fluid lines:

a pre-dilution infusion fluid line connected to the blood withdrawal line between the blood pump segment and the filtration unit,

an optional pre-blood pump infusion fluid line connected to the blood withdrawal line in a region of this latter which is positioned in use upstream the blood pump segment,

a post-dilution infusion fluid line connected to the blood return line,

a dialysis fluid line connected to the inlet of the secondary chamber;

wherein the control unit is configured to calculate the set value for the fluid flow rate through each of the above-listed infusion fluid lines which is not set by the operator based on said first fluid flow rate set by the operator and on said prescribed dose value (D_set).

8. The apparatus of claim 1, wherein said prescribed dose value (D_set) comprises a prescribed value for at least one flow rate, said prescribed dose value (D_set) comprises a prescribed value for one selected in the group including:

an effluent dose flow rate (D_{eff_set}), which is the prescribed mean value of the flow rate through the effluent line,

a convective dose flow rate (D_{conv_set}), which is the prescribed mean value of the sum of the flow rates through all infusion fluid lines (Q_rep1, Q_rep2, Q_pbp) and the patient fluid removal rate (Q_pfr),

a diffusive dose flow rate (D_{dial_set});

which is the prescribed mean value of the flow rate through the dialysis fluid line (Q_dial),

a urea dose (D_{urea_set}), which is a prescribed mean value for an estimated urea clearance,

a clearance dose (K_{solute_set}), which is a prescribed mean value for an estimated clearance for a given solute.

9. The apparatus of claim 8, comprising a fluid replacement line configured to deliver fluid upstream the treatment unit, wherein the control unit is configured to correct the selected one of the above defined doses to take into account a predilution effect, by multiplying the dose value times a dilution factor F_dilution, which is less than 1, as per the following formula:

Dose_{corr_xxx}=F_dilution×

Dose__xxx (with xxx=eff,conv,dial).

10. The apparatus of claim 1, wherein said first fluid flow rate is the fluid removal rate (Q_pfr) from the patient and wherein the control unit is configured to receive the set value of the patient fluid removal rate (Q_pfr) and to calculate the fluid flow rate (Q_dial) through the dialysis fluid line and the fluid flow rate (Q_rep1, Q_pbp, Q_rep2) through the infusion fluid line or lines using at least two of said mathematical relations.

11. An apparatus according to claim 1 wherein the control unit is further configured to perform one in the group of:

allow entry by an operator of the set value for a blood flow (Q_BLOOD) through the blood withdrawal or blood return line,

calculate the set value for the blood flow based on a sensed value of a patient parameter selected from the following group comprising;

blood pressure measured in a tract of the blood withdrawal line portion extending, in use, upstream the blood pump,

a measured blood recirculation fraction re-circulating from the blood return line into the blood withdrawal line,

a measured value of hemo-concentration measured in correspondence of one of the blood lines,

a measured value of transmembrane pressure across the semipermeable membrane,

wherein the control unit is further configured to control the blood pump using either the entered or the calculated set value for the blood flow (Q_BLOOD).

12. An apparatus according claim 1, wherein the control unit is further configured to calculate the set value for the fluid flow rate (Q_pbp) through said pre-blood pump infusion fluid line as a function of at least one of:

the set value of flow rate of blood or of plasma (Q_BLOOD;

Q_PLASMA),

a concentration (C_citrate) of an anticoagulant present in a container connected at an end of said pre-blood pump infusion fluid line, or

a prescribed dose for said anticoagulant (D_set-citrate) to be delivered through said pre-blood pump infusion fluid line.

13. The apparatus of claim 5, further comprising a graphical user interface connected to said control unit, said control unit being further configured to:

display on the graphical user interface an indicium prompting a user to select the value for said first flow rate,

display on the graphical user interface an indicium allowing selection of the mathematical relations the user intends to select, and

detect selection of a mathematical relation and display an indicium allowing selection of a set value for one or more of said first, second and third ratios.

14. The apparatus of claim 1, wherein the at least one solution pump comprises:

a pre-dilution pump for regulating the flow through said pre-dilution fluid line, a post-dilution pump for regulating the flow through said post-dilution fluid line, or a dialysis fluid pump for regulating the flow through a dialysis fluid line connected to the inlet of the secondary chamber.

15. Apparatus according to claim 1, comprising one or more of the following containers and respective lines:

a waste container connected to an end of the effluent fluid line,

a first container of fresh fluid connected to an end of the pre-dilution infusion fluid line,

a second container of fresh fluid connected to an end of the post-infusion fluid line,

a third container of fresh fluid connected to an end of the dialysis fluid line,

a fourth container of fresh fluid connected to an end of the pre-blood pump infusion fluid line,

memory storing one or more optimization criteria, said control unit being connected to said memory and being further configured to calculate the set values of at least one of the second and third fluid flow rates by applying the optimization criteria;

wherein the optimization criteria comprise one or more of;

a first optimization criterion imposing that emptying times of at least two among the containers of fresh fluid and the filling time of the waste container are multiple of a same reference time (T_r) more particularly wherein the first optimization criterion imposes that an emptying time of at least one among the containers of fresh fluid and a filling time of the waste container is substantially same as or multiple of the emptying time of one or more of the other containers of fresh fluid,

a second optimization criterion imposing that fluid consumption through said fluid lines is minimized,

a third optimization criterion imposing that a life time of said filtration unit is maximized,

a fourth optimization criterion imposes that urea clearance or dialysance of a given solute is maximized,

and wherein the control unit is configured to;

allow the user to select one or more of said optimization criteria and calculate said at least second and third flow rate using said selected optimization criteria, or

allow the user to select one or more of said optimization criteria and one or more of said mathematical relations and to calculate said at least second and third flow rate using said selected optimization criteria and said selected mathematical relations.

16. Apparatus according to claim 15 wherein the control unit is configured to determine if said selected optimization criteria and said selected mathematical relations are compatible or conflicting and:

in case the selected optimization criteria and the selected mathematical relations are compatible, calculate the at least second and third flow rate based on the selected mathematical relations and the optimization criteria,

in case one or more of the selected optimization criteria is conflicting with one or more selected mathematical relations execute one or more of the following sub-steps;

inform the user,

allow the user to assign a priority to each of the selected optimization criteria or mathematical relations, and

assign a priority ranking to the selected optimization criteria or mathematical relations, said priority ranking being either predetermined or user adjustable, and then ignore optimization criteria or mathematical relations as soon as flow rates have been calculated from the prioritized optimization criteria or mathematical relations,

define a compromise between conflicting optimization criteria or mathematical relations using preset rules.

17. Apparatus according to claim 1, wherein the control unit is configured to:

calculate set values for a plurality of flow rates and, at least for a first time interval, controlling said at least one solution pump based on the set values calculated; and

allow selection of one optimization criteria of the first, second, third and fourth optimization criteria, calculate the set values for a plurality of flow rates using the selected optimization criterion, and at least for a second time interval subsequent to the first time interval, controlling said at least one solution pump based on the set values calculated based on the selected optimization criterion.

18. 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 configured for connection to a patient cardiovascular system;

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

an effluent fluid line connected to an outlet of the secondary chamber with a waste container connected to an end of the effluent fluid line;

at least two further fluid lines selected from the group comprising;

a pre-dilution infusion fluid line connected at one end thereof to the blood withdrawal line with a first container of fresh fluid connected to another end of the pre-dilution infusion fluid line,

a post-dilution infusion fluid line connected at one end thereof to the blood return line with a second container of fresh fluid connected to another end of the post-dilution infusion fluid line,

a dialysis fluid line connected at one end thereof to the inlet of the secondary chamber with a third container of fresh fluid connected to an end of the dialysis fluid line, or

a pre-blood pump infusion fluid line connected at one end thereof to the blood withdrawal line in a region positioned in use upstream of the blood pump with a fourth container of fresh fluid connected to another end of the pre-blood pump infusion fluid line;

at least one pump configured to pump fluid through said fluid lines; and

a control unit operably connected to the at least one pump, the control unit configured to;

enter a set value by an operator for at least a first fluid flow rate selected from the group including;

a fluid flow rate (Q_rep1) through the pre-dilution infusion fluid line,

a fluid flow rate (Q_rep2) through the post-dilution infusion fluid line,

a fluid flow rate (Q_pbp) through the pre-blood pump infusion fluid line,

a fluid flow rate (Q_dial) through the dialysis fluid line, and

a fluid removal rate (Q_pfr) from the patient,

enter a set value by the operator for a prescribed dose (D_set) to be delivered, and

calculate set values of at least a second and a third of the fluid flow rates of said group of flow rates, based on the said first fluid flow rate and on said prescribed dose value (D_set) set by the operator, and

by applying an optimization criteria stored by a memory of the control unit, wherein the optimization criteria comprise one or more of;

a first optimization criterion imposing that emptying times of at least two among the containers of fresh fluid and the filling time of the waste container are a multiple of a same reference time (T_r), wherein at least three of the fluid flow rates of said group of flow rates are a function of said reference time (Tr), or

a second optimization criterion imposing that urea clearance or dialysance of a given solute is maximized, wherein the urea clearance or, respectively, the dialysance is a function of at least three of the fluid flow rates of said group of flow rates, and

wherein the application of the optimization criteria to the calculation of the at least second or third fluid flow rate reduces a number of flow rate set values entered into the control unit by the operator.

19. Apparatus according to claim 18, wherein the first optimization criterion if applied imposes at least one of (i) an emptying time of at least one of the containers of fresh fluid or (ii) a filling time of the waste container is substantially the same as or a multiple of the emptying time of one or more of the other containers of fresh fluid.

20. Apparatus according to claim 18, wherein the flow-rate setup procedure further comprises controlling said at least one pump based on said set values of the fluid flow rates.

21. Apparatus according to claim 18, wherein the control unit is configured to:

calculate set values for a plurality of flow rates and, at least for a first time interval, control said at least one pump based on the set values; and

allow selection of one or more of the first or second optimization criteria, calculate the set values for a plurality of flow rates using the selected at least one optimization criterion, and at least for a second time interval subsequent to the first time interval, control said at least one pump based on the set values calculated based on the selected optimization criterion.

22. The apparatus of claim 18, wherein said prescribed dose value (D_set) comprises a prescribed value for at least one flow rate, and said prescribed dose value (D_set) comprises a prescribed value for one selected in the group including:

an effluent dose flow rate (D_{eff_set}), which is the prescribed mean value of the flow rate through the effluent line;

a convective dose flow rate (D_{conv_set}), which is the prescribed mean value of the sum of the flow rates through all infusion fluid lines (Q_rep1, Q_rep2, Q_pbp) and the patient fluid removal rate (Q_pfr);

a diffusive dose flow rate (D_{dial_set}), which is the prescribed mean value of the flow rate through the dialysis fluid line (Q_dial);

a urea dose (D_{urea_set}), which is a prescribed mean value for an estimated urea clearance;

or

a clearance dose (K_{solute_set}), which is a prescribed mean value for an estimated clearance for a given solute.

23. The apparatus of claim 22, comprising a fluid replacement line configured to deliver fluid upstream the treatment unit, wherein the control unit is configured to correct the selected one of the above defined doses to take into account a predilution effect, by multiplying the dose value times a dilution factor F_dilution, which is less than 1, using the following formula:

Dose_{corr_xxx}=F_dilution×

Dose__xxx (with xxx=eff,conv,dial).

24. An apparatus according to claim 18, wherein the control unit is further configured to:

allow entry by an operator of the set value for a blood flow (Q_BLOOD) through the blood withdrawal or blood return line;

or

control the set value for the blood flow based on a sensed value of a patient parameter selected from the following group comprising;

blood pressure measured in a tract of the blood withdrawal line portion extending, in use, upstream of the blood pump,

a measured blood recirculation fraction re-circulating from the blood return line into the blood withdrawal line,

a measured value of hemo-concentration measured in correspondence of one of the blood lines, or

a measured value of transmembrane pressure across the filter semipermeable membrane,

wherein the control unit is configured to control the blood pump using either the entered or the calculated set value for the blood flow (Q_BLOOD).

25. An apparatus according claim 18, which further comprises calculating the set value for the fluid flow rate (Q_pbp) through said pre-blood pump infusion fluid line as a function of:

the set value of flow rate of blood or of plasma (Q_BLOOD;

Q_PLASMA);

a concentration (C_citrate) of an anticoagulant present in a container connected at an end of said pre-blood pump infusion fluid line; and

a prescribed dose for said anticoagulant (D_set-citrate) to be delivered through said pre-blood pump infusion fluid line.

26. The apparatus of claim 18, wherein the at least one pump includes at least one of:

a pre-dilution pump for regulating the flow through said pre-dilution fluid line, a post-dilution pump for regulating the flow through said post-dilution fluid line, or a dialysis fluid pump for regulating the flow through a dialysis fluid line connected to the inlet of the secondary chamber.

27. 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 configured for connection to a patient cardiovascular system;

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

an effluent fluid line connected to an outlet of the secondary chamber with a waste container connected to an end of the effluent fluid line;

at least two further fluid lines selected from the group comprising;

a pre-dilution infusion fluid line connected at one end thereof to the blood withdrawal line with a first container of fresh fluid connected to another end of the pre-dilution infusion fluid line,

a post-dilution infusion fluid line connected at one end thereof to the blood return line with a second container of fresh fluid connected to another end of the post-dilution infusion fluid line,

a dialysis fluid line connected at one end thereof to the inlet of the secondary chamber with a third container of fresh fluid connected to an end of the dialysis fluid line, or

a pre-blood pump infusion fluid line connected at one end thereof to the blood withdrawal line in a region positioned in use upstream of the blood pump with a fourth container of fresh fluid connected to another end of the pre-blood pump infusion fluid line;

at least one pump configured to pump fluid through said fluid lines; and

a control unit operably connected to the at least one pump, the control unit being configured to;

enter a set value by an operator for at least a first fluid flow rate selected from the group including;

a fluid flow rate (Q_rep1) through the pre-dilution infusion fluid line,

a fluid flow rate (Q_rep2) through the post-dilution infusion fluid line,

a fluid flow rate (Q_pbp) through the pre-blood pump infusion fluid line,

a fluid flow rate (Q_dial) through the dialysis fluid line, and

a fluid removal rate (Q_pfr) from the patient,

enter a set value by an operator for a prescribed dose (D_set) to be delivered, and

calculate set values of at least a second and a third of the fluid flow rates of said group of flow rates, based on the said first fluid flow rate set by the operator and on said prescribed dose value (D_set),

wherein said prescribed dose value (D_set) comprises a prescribed value selected from the group including;

a urea dose (D_{urea_set}), which is a prescribed mean value for an estimated urea clearance, wherein the urea dose (D_{urea_set}) is a function of at least three of the fluid flow rates of said group of flow rates, or

a clearance dose (K_{solute_set}), which is a prescribed mean value for an estimated clearance for a given solute, wherein the clearance dose (K_{solute_set}) is a function of at least three of the fluid flow rates of said group of flow rates, and

wherein the calculation of the at least second or third fluid flow rate reduces a number of flow rate set values entered into the control unit by the operator.

28. Apparatus according to claim 27, wherein the control unit is further configured to control said at least one pump based on said set values of the fluid flow rates.

29. The apparatus of claim 27, comprising a fluid replacement line configured to deliver fluid upstream the treatment unit, wherein the control unit is configured to correct the selected one of the above defined doses to take into account a predilution effect, by multiplying the dose value times a dilution factor F_dilution, which is less than 1, using the following formula:

Dose_{corr_xxx}=F_dilution×

Dose__xxx (with xxx=eff,conv,dial).