Method of setting a time-varying parameter in a blood treatment apparatus

• US 8,287,736 B2
• Filed: 06/28/2011
• Issued: 10/16/2012
• Est. Priority Date: 12/19/2005
• Status: Active Grant

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: Gambro Lundia AB (Baxter International Inc.)
• Inventors: Roncadi, Fabio, Salsa, Marco, Malagoli, Matteo, Sanders, Glenn, Warns, Gary
• Primary Examiner(s): CECIL, TERRY K
• Application Number:
  US13/170,375
• Publication Number:
  US 20110284464A1
• Time in Patent Office: 476 Days
• Field of Search: 700/83, 700/28, 700/32, 700/34, 210/646, 210/647, 210/96.2, 210/321.65, 210/929, 345/440, 702/85
• US Class Current: 210/647
• 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 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3324 PH measuring means
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/505 Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: G16H 20/40 relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: Y10S 210/929 Hemoultrafiltrate volume measurement or control processes

Abstract

A medical apparatus comprises a control system allowing storage of a number of shaping profiles. Each shaping profile is stored as a plurality of pairs, including a shaping profile reference value and a time interval value. The reference value is represented as fraction, for instance a percentage, of the total weight loss the apparatus should achieve at the end of a treatment time. Each time interval value is represented either as fraction of the total treatment time or as a prefixed actual time interval. The control system calculates the actual weight loss rate versus time profile based on the desired total weight loss, on the desired total treatment time as well as on selected desired shaping profile.

Claims

1. A method of setting a time-varying parameter in a blood treatment apparatus, the apparatus having at least a user interface and a control system configured to control operation of said blood treatment apparatus, the control system being connected to the user interface, said method comprising:

identifying a plurality of reference values defining a shaping profile,

identifying the value of at least a discriminating factor which relates to the time-varying parameter, and

calculating each of the parameter values as a function of a corresponding reference value of the shaping profile and of the value of said discriminating factor, wherein each of said reference values is represented as a fraction of the discriminating factor value, and wherein the calculation of each parameter value comprises the step of multiplying each reference value by the value of said discriminating factor

setting at least one time-varying parameter pertinent to operation of said apparatus or pertinent to a process to be performed by said apparatus, the time-varying parameter being defined by said plurality of parameter values that the at least one time-varying parameter takes during operation of the apparatus.

2. A method according to claim 1, wherein said setting comprises storing in a control system memory the calculated parameter values.

3. A method according to claim 1, wherein the apparatus comprises at least one actuator configured to cause displacement of a fluid in the blood treatment apparatus, the method comprising controlling at least one of the medical apparatus actuators using the values of the time-varying parameter across a treatment time.

4. A method according to claim 1, further comprising:

storing in a control system memory a plurality of shaping profiles to form a shaping profiles library,

allowing selection from the shaping profiles library of any of said shaping profiles, and

calculating the parameter values starting from reference values of the selected shaping profile.

5. A method according to claim 1, wherein said discriminating factor is one selected from the group comprising:

an integral of the values that the time-varying parameter takes over a treatment time;

a starting value taken by the time-varying parameter at the beginning of a treatment time;

an intermediate value taken by the time-varying parameter during a treatment time;

an end value taken by the time-varying parameter at the end of a treatment time;

a maximum value that is not exceeded by the time-varying parameter during a treatment time;

a minimum value below which the time-varying parameter will not drop during a treatment time; and

an average over a treatment time of the values that the time-varying parameter will take during the treatment time.

6. A method according to claim 1, wherein identifying the value of at least a discriminating comprises allowing a user to set said discriminating factor value via the user interface.

7. A method according to claim 1, further comprising storing in a control system memory said shaping profile as a plurality of pairs, each pair including a shaping profile reference value and a time interval value.

8. A method according to claim 1, wherein each time interval value is one of:

a fraction of the total treatment time and a prefixed time interval.

9. A method according to claim 8, wherein calculating a profile for said time-varying parameter uses said value of said discriminating factor and a total treatment time.

10. A method according to claim 9, wherein the profile for said time-varying parameter is calculated by determining each of said plurality of parameter values by:

multiplying each reference value by one of a value of the discriminating factor divided by the time interval value, a value of the discriminating factor, and a value proportional to a value of the discriminating factor; and

associating to each parameter value the actual time interval during which the parameter value remains constant for forming a step-shaped profile of said time-varying parameter.

11. A method according to claim 8, wherein the control system is programmed to check a sum of the time interval values and to generate an error signal if the sum is higher than a reference threshold value.

12. A method according to claim 1, further comprising checking a sum of the reference values and generating an error if the sum is higher than a reference threshold value.

13. A method according to claim 1, wherein the blood treatment apparatus is an extracorporeal blood treatment machine comprising:

a treatment liquid line configured to provide fresh dialysis liquid, fresh substitution solution, or both fresh dialysis liquid and fresh substitution solution;

at least a waste line configured to receive spent liquid; and

a blood treatment unit having a first chamber connected to the treatment liquid line and to the waste line, and a second chamber connected to a blood removal line and to a blood return tubing, said first and second chambers being separated by a semipermeable membrane; and

wherein the time-varying parameter is at least one of;

temperature of the dialysis liquid;

conductivity of the dialysis liquid;

electrolyte concentration of the dialysis liquid;

temperature of the substitution solution;

conductivity of the substitution solution;

electrolyte concentration of the substitution solution;

flow rate of the dialysis liquid;

flow rate of the spent liquid;

flow rate of the substitution solution;

flow rate of the blood in one of said tubing;

ultrafiltration rate through the semipermeable membrane;

net weight loss rate;

net weight loss during a time interval;

temperature of a medicament infusion solution;

medicament concentration of a medicament infusion solution; and

flow rate of a medicament infusion solution.

14. A method according to claim 13, wherein the time-varying parameter is one of a net weight loss rate and a net weight loss during a time interval, and the method comprises calculating a profile for said time-varying parameter as function of said plurality of reference values of the shaping profile, of said discriminating factor value and of the treatment time.

15. A method according to claim 14, wherein the discriminating factor value is the total weight loss to be achieved at the end of treatment time.

16. A method according to claim 15, further comprising storing said shaping profile as a plurality of pairs, each pair including a shaping profile reference value and a time interval value, each reference value being represented as fraction of the total weight loss, and each time interval value being represented either as fraction of the total treatment time or as a prefixed actual time interval.

17. A method according to claim 15, further comprising:

storing a plurality of shaping profiles to form a shaping profiles library,

selecting the total weight loss and the total treatment time,

selecting from the shaping profiles library any of said shaping profiles,

multiplying the shaping profile reference values by the value of the total weight loss for obtaining a plurality of actual weight loss portions,

multiplying the time interval values by the total treatment time value to obtain actual time intervals, and

associating each actual weight loss portion with the respective actual time interval during which the actual weight loss portion will be achieved.

18. A method according to claim 15, further comprising:

storing a plurality of shaping profiles to form a shaping profiles library,

selecting the total weight loss and the total treatment time,

electing from the shaping profiles library any of said shaping profiles,

multiplying the time interval values by the total treatment time value to obtain actual time intervals, and

multiplying the shaping profile reference values by the value of the total weight loss and dividing by the respective actual time interval for obtaining a plurality of pairs representing the profile of said time-varying parameter, each pair including a weight loss rate value and the corresponding actual time interval value during which the weight loss rate is constant.

19. A method according to claim 15, further comprising:

storing a plurality of shaping profiles to form a shaping profiles library,

selecting from the shaping profiles library any of said shaping profiles,

selecting the total weight loss, and

multiplying the shaping profile reference values by the value of the total weight loss and dividing by the respective prefixed actual time interval for obtaining a plurality of pairs representing the profile of said time-varying parameter, each pair including a weight loss rate value and the corresponding prefixed actual time interval value during which the weight loss rate is constant.

20. A method according to claim 15 comprising associating to each pair a third value indicating whether the respective pair refers to a pure ultrafiltration treatment step wherein the spent liquid flowing in the waste line is corporeal fluid only, said corporeal fluid coming from the second chamber of the treatment unit via filtration through said membrane.

21. A method according to claim 13 comprising storing the shaping profile as a plurality of pairs, each pair including a shaping profile reference value and a respective time interval value, wherein each time interval value is one of:

a fraction of the total treatment time, and

a prefixed time interval, and

wherein each reference value is stored as a fraction of total weight loss to be removed by a patient during said total treatment time.

22. A method according to claim 21, comprising associating to each pair a third value indicating whether the respective pair refers or not to a pure ultrafiltration treatment step wherein the spent liquid flowing in the waste line is corporeal fluid only, said corporeal fluid coming from the second chamber of the treatment unit via filtration through said membrane.

23. A method according to claim 1, wherein the user interface includes a screen configured for displaying a plurality of indicia for allowing selection of the shaping profile, the method comprising selecting the shaping profile via the indicia and displaying a graphic representation of the selected shaping profile at least on a portion of said screen, said graphic representation being one of:

a Cartesian representation wherein reference values are represented as percentages of the total weight loss and time intervals as percentages of the total treatment time, and

a table representation, wherein reference values are represented as percentages of the total weight loss and time intervals as percentages of the total treatment time.

24. A method according to claim 23 comprising:

selection of a shaping profile;

modification of one or more of the reference values or time interval values of the selected shaping profile for creating a new shaping profile; and

storage of the new shaping profile if a sum of the reference values thereof and the sum of the time interval values do not exceed respective threshold values.

25. A method according to claim 23 comprising creation of a new shaping profile, said creation comprising the following sub-steps:

entry of a plurality of reference values and corresponding time interval values,

verification if the sum of the reference values and the sum of the time interval values do not exceed respective threshold values, and

storage of the pairs of newly entered reference values and corresponding time interval values to form a new shaping profile if the verification step has been passed.

26. A method according to claim 23 comprising first allowing entry of the total weight loss and of the total treatment time before allowing selection of one of said plurality of indicia.

27. A method according to claim 23, wherein the time-varying parameter is the net weight loss rate, and wherein the method comprises:

starting of the blood treatment, allowing to select a shaping profile after treatment start, and

computing the profile of the net weight loss rate using, as total treatment time, the total treatment time entered at the beginning of the treatment less the elapsed treatment time and using, as total weight loss, the total weight loss entered at the beginning of the treatment less the fluid weight already removed.

28. A method according to claim 23, wherein the time-varying parameter is the net weight loss rate, and wherein the method comprises:

starting of the blood treatment, allowing modification of the total treatment time while treatment is in progress,

recalculating the weight loss rate profile data using the selected shaping profile and the new treatment time, taking into account the amount of time that has already elapsed since a start of the treatment.

29. A method according to claim 23, wherein the time-varying parameter is the net weight loss rate, and wherein the method comprises:

starting of the blood treatment,

modifying of the total weight loss while treatment is in progress, and

recalculating the weight loss rate profile data using the selected shaping profile and the new weight loss, taking into account the amount of fluid that has already been removed since treatment start.

30. A method according to claim 23, wherein the time-varying parameter is the net weight loss rate, and wherein the method comprises:

starting of a blood treatment session and

deactivating of a previously activated weight loss rate profile during a treatment,

setting the net weight loss rate to a constant value equal to a target total weight loss remaining divided by a time remaining in the treatment.

31. A method according to claim 23, wherein the time-varying parameter is the net weight loss rate, and wherein the method comprises:

starting an error compensation procedure if a set total weight loss cannot be reached using a set weight loss rate profile, the compensation procedure comprising the following steps;

computing an UF deficit as an extra amount of fluid that should be removed to fulfill the set total weight loss, and

adding the UF deficit proportionally to the remaining steps in the step profile controls the UF rate to according to the new profile.

32. A method according to claim 23, wherein the time-varying parameter is the net weight loss rate, and wherein the method comprises:

checking if all steps of an ultrafiltration profile are greater than or equal to the minimum allowed UF value and if all steps of the ultrafiltration profile are lower than a maximum allowed UF value, and

storing and executing a profile only if above check is positively passed.

33. A method of setting a time-varying parameter in blood treatment apparatus, the apparatus having at least a user interface and a control system configured to control operation of said blood treatment apparatus, the control system being connected to the user interface, said method comprising:

identifying a plurality of reference values defining a shaping profile, shaping profile being identified as a plurality of pairs, each pair including a shaping profile reference value and a time interval value,

identifying the value of at least a discriminating factor which relates to the time-varying parameter, the time-varying parameter being the net weight loss rate, and the value of the discriminating factor being the total weight loss to be achieved at the end of a total treatment time, and

calculating each of the parameter values as a function of a corresponding reference value of the shaping profile and of the value of said discriminating factor by;

multiplying the time interval values by the total treatment time value to obtain actual time intervals, and

multiplying the shaping profile reference values by the value of the total weight loss and dividing by the respective actual time interval for obtaining a plurality of pairs representing the profile of said time-varying parameter, each pair including a weight loss rate value and the corresponding actual time interval value during which the weight loss rate is constant.

34. The method according to claim 33, further comprising setting at least one time-varying parameter pertinent to operation of said apparatus or pertinent to a process to be performed by said apparatus, the time-varying parameter being defined by said plurality of parameter values that the at least one time-varying parameter takes during operation of the apparatus.

35. A method of setting a time-varying parameter in blood treatment apparatus, the apparatus having at least a user interface and a control system configured to control operation of said blood treatment apparatus, the control system being connected to the user interface, said method comprising:

identifying a plurality of reference values defining a shaping profile,

identifying the value of at least a discriminating factor which relates to the time varying parameter, the time-varying parameter being the net weight loss rate, and the value of the discriminating factor being the total weight loss to be achieved at the end of a total treatment time, and

calculating each of the parameter values as a function of a corresponding reference value of the shaping profile and of the value of said discriminating factor by;

multiplying the shaping profile reference values by the value of the total weight loss and dividing by a respective pre-fixed actual time interval for obtaining a plurality of pairs representing the profile of said time-varying parameter, each pair including a weight loss rate value and the corresponding prefixed actual time interval value during which the weight loss rate is constant.

36. The method of claim 35 comprising setting at least one time-varying parameter pertinent to operation of said apparatus or pertinent to a process to be performed by said apparatus, the time-varying parameter being defined by said plurality of parameter values that the at least one time-varying parameter takes during operation of the apparatus.

37. A method of setting a time-varying parameter in blood treatment apparatus, the apparatus having at least a user interface and a control system configured to control operation of said blood treatment apparatus, the control system being connected to the user interface, said method comprising:

identifying a plurality of reference values defining a shaping profile,

identifying the value of at least a discriminating factor which relates to the time-varying parameter, the time-varying parameter being the net weight loss during a time interval and the discriminating factor value being the total weight loss to be achieved at the end of a total treatment time, and

calculating each of the parameter values as a function of a corresponding reference value of the shaping profile and of the value of said discriminating factor by;

multiplying the shaping profile reference values by the value of the total weight loss for obtaining a plurality of actual weight loss portions,

multiplying time interval values by the total treatment time value to obtain actual time intervals, and

associating each actual weight loss portion with the respective actual time interval during which the actual weight loss portion is achieved.

38. The method of claim 37 comprising setting at least one time-varying parameter pertinent to operation of said apparatus or pertinent to a process to be performed by said apparatus, the time-varying parameter being defined by said plurality of parameter values that the at least one time-varying parameter takes during operation of the apparatus.