Adjustably controllable accuracy-enhancing pump arrangement and method

• US 5,024,347 A
• Filed: 06/08/1988
• Issued: 06/18/1991
• Est. Priority Date: 06/08/1988
• Status: Expired due to Fees

• Current Assignee: BAXA Corporation (Baxter International Inc.)
• Original Assignee: Brian E. Baldwin
• Inventors: Baldwin, Brian E.
• Primary Examiner(s): Huppert, Michael S.
• Assistant Examiner(s): Huson, Gregory L.
• Application Number:
  US07/203,924
• Time in Patent Office: 1,105 Days
• Field of Search: 222/14, 222/63, 222/207, 222/214, 222/1, 222/55, 417/44-45, 417/22, 417/477, 604/30, 604/65, 604/67, 364/510
• US Class Current: 222/1
• CPC Class Codes: F04B 43/1253 by using two or more rollers as squeezing elements, the rollers moving on an arc of a circle during squeezing
• CPC Class Codes: F04B 49/065 and making use of computers

Abstract

An adjustably controllable accuracy-enhancing pump arrangement and method is disclosed, as embodied in a digitally pulse-driven rotary peristaltic pump having a rotor which acts on a fluid pumping conduit to effect pumped output of fluid. Inaccuracies in volume pumped for a given quantity of pulses applied to the pump intended to effect a selected desired volume are minimized by adjusting the total quantity of pulses applied to the pump for a given desired volume, and/or for subsequent selected volumes, if desired, as a function of an adjustment factor formed by the ratio of the given desired volume relative to actual volume pumped by the application to the pump of the quantity of pulses estimated or calculated to be required for pumping the given desired volume through a given sized tube set conduit.

Claims

1. The method of reducing inaccuracy in total quantity of fluid pumped by a pump comprising:

actuating a pump through a first given amount of pump activity which is estimated will yield a first selected output quantity of a given fluid pumped through a given conduit based on assumed calibration factor of a selected amount of pump activity per unit volume dispensed,

measuring the amount of the actual output quantity of said fluid which is pumped through said conduit by said first given amount of pump activity,

and applying an adjustment factor to the amount of pump activity which would be calculated to be required based on said assumed calibration factor, for further pumping activity to effect selected further pumped output quantity production, said adjustment factor when applied as a multiplier being equal to the ratio of said first selected output quantity of fluid pumped relative to said measured actual output quantity of fluid pumped, for further pumping of a said selected further output quantity.

2. The method according to claim 1, further comprising

applying the respective said adjustment factor to subsequent pump activity for pumping selected further pumped output quantities of said given fluid through said given conduit whether the same as or different from said first selected output quantity.

3. The method according to claim 1, further comprising

subsequently changing said given conduit to a second conduit having a fluid flow rate characteristic different from that of said first conduit,

actuating a pump through a further given amount of pump activity which is considered will yield a second selected output quantity of a given fluid pumped through said second given conduit,

measuring the amount of the actual output quantity of said fluid which is pumped through said conduit by said further given amount of pump activity,

and adjusting the said further given amount of pump activity of said pump, when pumping its output through said second conduit, by a second adjustment factor multiple equal to the ratio of said second selected output quantity of fluid pumped relative to said measured actual output quantity of fluid pumped through a said second conduit when said pump is actuated through said further given amount of pump activity.

4. The method according to claim 3,

and applying said second adjustment factor to subsequent pump activity for pumping a selected further pumped output quantity of said given fluid through said second given conduit, as may be desired, independent of whether such selected further pumped output quantity is the same as or different from said second selected output quantity.

5. The method according to claim 1, further comprising:

subsequently changing said given fluid to a selected second fluid having a flow rate characteristic different from that of the previously pumped said given fluid,

actuating a pump through a further amount of pump activity which is considered will yield a further selected output quantity of said selected second fluid pumped through a particular conduit,

measuring the amount of the actual output quantity of said selected second fluid which is pumped through said particular conduit by said further amount of pump activity,

and adjusting the said further amount of pump activity by an adjustment factor multiple equal to the ratio of said further selected output quantity of fluid pumped relative to said measured actual output quantity of said selected second fluid pumped.

6. The method according to claim 5, further comprising:

applying the respective said adjustment factor to pump activity for pumping a selected further pumped output quantity of at least one of said given fluid and said selected second fluid.

7. The method according to claim 1, further comprising:

applying said adjustment factor to subsequent pump activity for further pumping of a selected further pumped output quantity of said given fluid through said given conduit independent of whether such selected further pumped output quantity is the same as or different from said first selected output quantity.

8. The method according to claim 7,

said applying of said adjustment factor to said subsequent pump activity being for pumping of a quantity of fluid different from said first selected output quantity.

9. The method according to claim 7,

said applying of said adjustment factor to said subsequent pump activity being for pumping of a quantity of fluid the same as said first selected output quantity.

10. The method according to claim 7,

said applying of said adjustment factor to said estimated quantity of subsequent pump activity being for pumping of both at least one quantity of fluid the same as said first selected output quantity and at least one quantity of fluid different from said first selected output quantity.

11. The method of reducing inaccuracy in the amount of output fluid pumped through a conduit by a digitally incrementally operable pump, comprising

actuating a digitally incrementally operable pump through a first given amount of pump activity represented by a first quantity of digital increments, which is estimated will yield a first selected output quantity of a given fluid pumped through a given conduit based on an assumed calibration factor of a selected amount of pump activity per unit volume dispensed,

measuring the amount of the actual output quantity of said fluid which is pumped through said conduit by said first given amount of pump activity represented by said first quantity of digital increments,

applying an adjustment factor to the amount of pump activity which would be calculated to be required based on said assumed calibration factor, for further pumping activity to effect selected further pumped output quantity production,

said adjustment factor when applied as a multiplier being equal to the ratio of said first selected output quantity of fluid pumped relative to said measured actual output quantity of fluid pumped as a result of said estimated number of increments of actuation of said pump, for further pumping of a said selected further pumped output quantity,

and subsequently a selected output quantity of said given fluid through said conduit by actuating said pump a number of increments equal to the product of said estimated quantity of increments corresponding to said selected output quantity multiplied by said adjustment factor.

12. The method according to 11, further comprising

applying said adjustment factor to subsequent pump activity for pumping a subsequent selected pumped output quantity of said given fluid through said given conduit whether the same as or different from said first selected output quantity.

13. The method according to claim 11, further comprising:

applying said adjustment factor to subsequent pump activity for pumping a further selected pumped output quantity of said given fluid through said given conduit independent of whether such selected further pumped output quantity is the same as or different from said first selected output quantity.

14. The method of reducing inaccuracy in the output amount of a given fluid pumped through a selected conduit by a stepping motor-driven pump, comprising

pulsing a stepping motor-actuated pump a given number of actuating pulses estimated as corresponding to a first desired output quantity of selected fluid output of a given fluid through a selected conduit based on a first ratio of n estimated pulses/unit volume pumped, and said number of pulses being equal to the product of said desired quantity of selected fluid multiplied by said first ratio,

measuring the actual first output quantity of said given fluid pumped through said conduit as a result of pulse-actuating said pump said given number of actuating pulses,

and subsequently pulsing said stepping motor-actuated pump for outputting any selected user quantity of said given fluid through said conduit by pulsing said stepping motor-actuated pump a number of pulses equal to the product of said selected user quantity of fluid multiplied by said first ratio and by a further second corrective adjustment factor which is the ratio formed by said first desired output quantity divided by said measured actual first output quantity.

15. The method according to claim 14, further comprising:

applying said adjustment factor to subsequent pump activity for pumping a selected further pumped output quantity of said given fluid through said given conduit independent of whether such selected further pumped output quantity is the same as or different from said first selected user quantity to have been outputted theretofore.

16. The method according to claim 14, further comprising:

applying said adjustment factor to subsequent pump activity for pumping selected further pumped output quantities of said given fluid through said given conduit independent of whether such selected further pumped output quantities are the same as or different from the previous said selected user quantity to have been outputted theretofore.

17. A pump arrangement enabling reduction of inaccuracy in the amount of output fluid pumped through a conduit by

a digitally incrementally operable pump, comprising

a digitally incrementally operable pump,

means for actuating said pump through a first given amount of pump activity represented by a first quantity of digital increments, which is estimated will yield a first selected output quantity of a given fluid pumped through a given conduit based on an assumed calibration factor of a selected amount of pump activity per unit volume dispensed,

means for applying an adjustment factor to the amount of pump activity which would be calculated to be required based on said assumed calibration factor, for further pumping activity to effect selected further pumped output quantity production,

said adjustment being applied as a multiplier which is equal to the ratio of said first selected output quantity of fluid pumped relative to an actual measured output quantity of fluid pumped through a given said conduit as a result of said estimated number of increments of actuation of said pump,

and means for subsequently pumping a selected output quantity of said given fluid through said conduit by actuating said pump a number of increments equal to the product of said adjustment factor and said estimated quantity of increments corresponding to said selected output quantity.

18. Apparatus according to claim 17, further comprising:

means for applying said adjustment factor to subsequent pump activity for pumping a further selected pumped output quantity of a said given fluid through a said given conduit independent of whether such selected further pumped output quantity is the same as or different from said first selected output quantity.

19. A pump arrangement which enables reduction of inaccuracy in the output amount of a given fluid pumped through a selected conduit by a pulse-actuated pump, comprising

a digital pulse-actuated pump, means for pulsing said pump a given number of actuating pulses estimated as corresponding to a first desired output quantity of a selected fluid output by said pump of a given fluid through a selected conduit based on a first ratio of n estimated pulses/unit volume pumped, and said number of pulses being equal to the product of said desired quantity of selected fluid multiplied by said first ratio,

and means for subsequently pulsing said digital pulse-actuated pump for outputting any selected user quantity of said given fluid through said conduit by pulsing said stepping motor-actuated pump a number of pulses equal to the product of said selected user quantity of fluid multiplied by said first ratio and by a further second corrective adjustment factor which is the ratio formed by said first desired output quantity divided by an actual first output quantity from said pump when said pump is actuated a number of pulses equal to said product of said desired quantity multiplied by said first ratio,.

20. Apparatus according to claim 19, further comprising:

means for applying said adjustment factor to subsequent pump activity of said pump for pumping a selected further pumped output quantity of a said given fluid through said given conduit independent of whether such selected further pumped output quantity is the same as or different from said first selected user quantity to have been outputted theretofore.

21. Apparatus according to claim 19, further comprising:

means for applying said adjustment factor to subsequent pump activity for said pump for pumping selected further pumped output quantities of said given fluid through said given conduit independent of whether such selected further pumped output quantities are the same as or different from the previous said selected user quantity to have been outputted theretofore.

22. A pump arrangement enabling reduction of inaccuracy in total quantity of fluid pumped by a pump, comprising:

a pump,

means for actuating said pump through a first given amount of pump activity which is estimated will yield a first selected output quantity of a given fluid pumped through a given conduit based on an assumed calibration factor of a selected amount of pump activity per unit volume dispensed,

and means for applying an adjustment factor to the amount of pump activity which would be calculated to be required based on said assumed calibration factor, said adjustment factor being a multiplier which is equal to the ratio of said first selected output quantity of fluid pumped relative to an actual measured output quantity of fluid pumped through a said given conduit by said pump when said pump is actuated by said first given amount of pump activity, for further pumping of said selected further output quantity.

23. The method according to claim 22, further comprising

means for applying the respective said adjustment factor to selected subsequent pump activity of said pump for pumping selected further pumped output quantities of said given fluid through said given conduit whether the same as or different from said first selected output quantity.

24. Apparatus according to claim 22, further comprising:

means for subsequently changing said given conduit to a second conduit having a fluid flow rate characteristic different from that of said first conduit,

means for actuating said pump through a further given amount of pump activity which is considered will yield a second selected output quantity of a given fluid pumped through said second given conduit,

and means for adjusting the said further given amount of pump activity of said pump, when pumping its output through said second conduit, by a second adjustment factor multiple equal to the ratio of said second selected output quantity of fluid pumped relative to an actual measured output quantity of fluid pumped through a said second conduit when said pump is actuated through said further given amount as pump activity.

25. Apparatus to claim 24,

and means for applying said second adjustment factor to subsequent pump activity for pumping a selected further pumped output quantity of said given fluid through said second given conduit, as may be desired, independent of whether such selected further pumped output quantity is the same as or different from said second selected output quantity.

26. Apparatus according to claim 22 further comprising:

means for actuating said pump through a further amount of pump activity by said pump which is considered will yield a further selected output quantity of a selected second fluid pumped through a particular conduit, which second fluid has a flow rate characteristic different from that of the previously pumped said given fluid,

and means for adjusting the said further amount of pump activity by an adjustment factor multiple equal to the ratio of said further selected output quantity of fluid pumped relative to an actual measured output quantity of said selected second fluid pumped by said pump as a result of said further amount of pump activity.

27. The method according to claim 26, further comprising:

means for applying the respective said adjustment factor to additional pump activity of said pump for pumping a selected further pumped output quantity of at least one of said given fluid and said selected second fluid.

28. Apparatus according to claim 22,

and means for applying said adjustment factor to subsequent pumping activity of said pump for further pumping of a selected further pumped output quantity of said given fluid through a said given conduit independent of whether such selected further pumped output quantity is the same as or different from said first selected output quantity.

29. Apparatus according to claim 28,

said means for applying of said adjustment factor to said subsequent pump activity comprising means for pumping of a quantity of fluid different from said first selected output quantity.

30. Apparatus according to claim 28,

said means for applying of said adjustment factor to said subsequent pump activity comprising means for pumping of a quantity of fluid the same as said first selected output quantity.

31. Apparatus according to claim 28,

said means for applying of said adjustment factor to said estimated quantity of subsequent pump activity including means for pumping of both at least one quantity of fluid the same as said first selected output quantity and at least one quantity of fluid different from said first selected output quantity.