Fluid dispenser with stabilized fluid flow

• US 6,413,238 B1
• Filed: 09/17/1999
• Issued: 07/02/2002
• Est. Priority Date: 09/17/1999
• Status: Expired due to Term

• Current Assignee: Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Maget, Henri J. R.
• Primary Examiner(s): KENNEDY, SHARON E
• Application Number:
  US09/397,944
• Time in Patent Office: 1,019 Days
• Field of Search: 604/131-133, 604/140, 604/141, 604/143-145, 604/151, 604/890.1, 604/891.1, 604/27, 604/28, 604/30, 604/31, 604/503-505, 604/65, 604/67, 604/93.01, 128/DIG.12
• US Class Current: 604/132
• CPC Class Codes: A61M 2005/14204 with gas-producing electrochemical cell
• CPC Class Codes: A61M 2005/14264 with means for compensating influence from the environment
• CPC Class Codes: A61M 2005/14513 with secondary fluid driving or regulating the infusion
• CPC Class Codes: A61M 2205/3355 Controlling downstream pump pressure
• CPC Class Codes: A61M 5/14526 the piston being actuated by fluid pressure
• CPC Class Codes: A61M 5/16886 for measuring fluid flow rate, i.e. flowmeters

Abstract

A fluid dispensing device and its method of operation are disclosed. The device includes a feedback system which allows the device to respond in a timely and measured manner to changes in the dispensing flow rate of fluid from the device. The feedback system operates effectively even under conditions where the cause of increase or decrease in flow rate is not unequivocally known or reasonably capable of direct measurement. The device has a fluid reservoir which has an outlet which optionally may have a flow or pressure resistance unit incorporated, into the outlet, and an electric (preferably electrochemical) gas generation module or reversible pump which provides gas pressure to dispense the fluid from the reservoir. A sensor is provided for detection and measurement of an internal or external operating parameter which is indicative of flow rate of the fluid being dispensed. Feedback from the sensor (and associated signal processing unit) is used by a controller to control electric current to the gas generation module, with the current being adjusted by the controller to adjust the amount of gas produced in a manner which will prevent the flow rate of the dispensed fluid from exceeding desired maximum or minimum limits.

Claims

1. A fluid dispensing device comprising:

a housing having an internal fluid reservoir divided by a movable fluid-tight partition into first and second chambers on opposite sides of said partition;

electrically operated gas generation/extraction module for moving a gas into or out of said first chamber, said gas therein exerting or reducing pressure on said partition;

controllable source of electric current for operation of said module, said source connected to a controller for controlling said source to vary the amount or polarity or both of said electrical current to said module and thereby operate said module to change its rate of gas generation or extraction, said controller being responsive to a measurable parameter associated with said device;

fluid outlet from said second chamber for dispensing of fluid contained in said second chamber exteriorly of said device in response to said pressure on said partition; and

sensor means for detection and measurement of said parameter over time and generation of a signal to said controller indicating quantity and direction of any change in said parameter, said controller in response to said signal indicating said change in said parameter varying said electric current to said module to effect said change in rate of gas generation or extraction;

whereby said change in said rate of gas generation or extraction effects a change in gas pressure in said first chamber and resultant change in said pressure on said partition, said pressure change being in a direction and amount sufficient to keep said fluid flow from said second chamber at any time from exceeding predetermined minimum and maximum values of said parameter.

2. A device as in claim 1 wherein said sensor detects and measures a physical, chemical or biological parameter.

3. A device as in claim 2 wherein said sensor detects and measures a parameter comprising at least one of fluid pressure within said first chamber or said second chamber, fluid pressure at an exit of said fluid outlet, concentration of a component of said fluid, pressure drop across said partition, temperature within said reservoir, volume of said fluid within said second chamber, volume rate of discharge of said fluid from said second chamber or said fluid outlet or strain in a wall of said reservoir.

4. A device as in claim 2 wherein said parameter exists at a location exteriorly of said device and said sensor is disposed exteriorly of said device to detect and measure said parameter.

5. A device as in claim 4 wherein said sensor detects and measures a parameter comprising a reaction condition of a chemical or biological reaction to which said fluid is dispensed, a bodily condition of a human being or animal to whom said fluid is being administered, an ambient environmental condition adjacent to said device, or a property of dispensed fluid at a location exteriorly of said device.

6. A device as in claim 1 wherein said sensor is disposed between said gas generation module and said first chamber or fully or partially in said first chamber or said second chamber or at an exit of said fluid outlet.

7. A device as in claim 1 wherein said second chamber contains a gas, a vapor or a vapor- or gas-emitting substance and said fluid dispensed from said second chamber comprises gas or vapor.

8. A device as in claim 1 wherein said second chamber contains a liquid or a liquid-emitting substance and said fluid dispensed from said second chamber comprises liquid.

9. A device as in claim 1 wherein said controller comprises a microprocessor.

10. A device as in claim 1 wherein said moveable partition comprises plunger, a piston head or a flexible sheet.

11. A fluid dispensing device comprising:

a housing having an internal fluid chamber comprising a gas chamber and a fluid chamber separated by a moveable pressure responsive partition, said fluid chamber having a fluid conduit providing fluid communication between said fluid liquid chamber and an outlet end of said conduit, said outlet end opening to an exterior of said housing;

pumping means comprising an electrochemical cell in gas communication with said gas chamber, for pumping gas into or out of said gas chamber, said gas when in said chamber exerting pressure against said pressure responsive partition causing responsive movement thereof of fluid in said liquid chamber, said responsive movement comprising said fluid moving toward and through said fluid conduit to said exterior of said housing or being withdrawn from said conduit into said liquid chamber;

controllable source of electric current for operation of said pumping means, said source connected to a controller for controlling said source to vary the amount and polarity of said electrical current to said pumping means and thereby operate said pumping means to change its rate or direction of pumping of said gas, said controller being responsive to a measurable parameter associated with said device; and

sensor means for detection and measurement of said parameter overtime and generation of a signal to said controller indicating quantity and direction of any change in said parameter, said controller in response to said signal indicating said change in said parameter varying said electric current to said module to effect said change in rate of gas generation;

whereby upon said change in said measured parameter, said controller regulates said amount and polarity of said electrical current to said pumping means to increase or decease rate of pumping of said gas or change direction of pumping of said gas, such that fluid flow to or from said fluid chamber rate maintains a cumulative total of said fluid discharged from said fluid chamber to a target environment over a selected period of time to be within a predetermined range.

12. A device as in claim 11 wherein said sensor detects and measures a physical, chemical or biological parameter.

13. A device as in claim 12 wherein said sensor detects and measures a parameter comprising at least one of fluid pressure within said gas chamber or said fluid chamber, fluid pressure at an exit of said fluid chamber, concentration of a component of said fluid, pressure drop across said partition, temperature within said reservoir, volume of said fluid within said fluid chamber, volume rate of discharge of said fluid from said fluid chamber or said fluid outlet or strain in a wall of said reservoir.

14. A device as in claim 11 wherein said sensor is disposed between said pumping means and said gas chamber or fully or partially in said gas chamber or said fluid chamber or at an exit of said fluid chamber.

15. A device as in claim 11 wherein said parameter exists at a location exteriorly of said device and said sensor is disposed exteriorly of said device to detect and measure said parameter.

16. A device as in claim 15 wherein said sensor detects and measures a parameter comprising a reaction condition of a chemical or biological reaction to which said fluid is dispensed, a bodily condition of a human being or animal to whom said fluid is being administered, an ambient environmental condition adjacent to said device, or a property of dispensed fluid at a location exteriorly of said device.

17. A device as in claim 11 wherein said fluid chamber contains a gas, a vapor or a vapor- or gas-emitting substance and fluid dispensed from said fluid chamber comprises gas or vapor.

18. A device as in claim 11 wherein said fluid chamber contains a liquid or a liquid-emitting substance and said fluid dispensed from said fluid chamber comprises liquid.

19. A device as in claim 11 wherein said controller comprises a microprocessor.

20. A device as in claim 11 wherein said moveable partition comprises plunger, a piston head or a flexible sheet.

21. A device as in claim 11 comprising a syringe.

22. A device as in claim 21 wherein said syringe comprises a elongated hollow cylindrical body having a first end and an opposite second end, and said moveable pressure responsive partition comprises a moveable plunger within said hollow cylindrical body and disposed intermediate said first and second ends, that portion of said body adjacent said first end comprising said gas compartment and that portion of said body adjacent said second end comprising said fluid compartment, with said plunger separating said compartments.

23. A device as in claim 22 further comprising said pumping module comprising said electrochemical cell being disposed in said first end such that gas generated by said electrochemical cell is pumped directly into said gas compartment.

24. A device as in claim 23 further comprising said pressure sensor being disposed at an interface between said pumping module and said gas chamber.

25. A device as in claim 22 further comprising said plunger being moveable longitudinally of said hollow cylindrical body, such that longitudinal movement of said plunger toward said second end of said body acts to expel fluid contained within said fluid compartment from said compartment through a fluid outlet conduit, flow rate of expelled fluid through said outlet end being determined by the pressure of said gas in said gas chamber exerting motivating force against said plunger to effect said longitudinal movement.

26. A device as in claim 25 wherein said fluid outlet conduit comprises an hollow elongates flexible tube.

27. A device as in claim 26 wherein at said outlet end of said conduit is disposed a hollow needle or cannula through which fluid expelled from said device can be injected into a human or animal.

28. A method for dispensing fluid from a fluid-containing device comprising:

providing a fluid dispensing device comprising;

a housing having an internal fluid reservoir divided by a movable fluid-tight partition into first and second chambers on opposite sides of said partition;

electrically operated gas generation module for generating gas and moving said gas into said first chamber, said gas therein exerting pressure on said partition;

controllable source of electric current for operation of said module, said source connected to a controller for controlling said source to vary the amount of said electrical current to said module and thereby operate said module to change its rate of gas generation, said controller being responsive to a measurable parameter associated with said device;

fluid outlet from said second chamber for dispensing of fluid contained in said second chamber exteriorly of said device in response to said pressure on said partition; and

sensor means for detection and measurement of said parameter over time and generation of a signal to said controller indicating quantity and direction of any change in said parameter, said controller in response to said signal indicating said change in said parameter varying said electric current to said module to effect said change in rate of gas generation;

operating said sensor such that said sensor detects a change in said parameter over a period of time and generates said signal to said controller;

operating said controller such that said controller decreases or increases said amount of current or changes polarity of said current, said decrease, increase or change in polarity effecting a change in gas pressure in said first chamber and resultant change in said pressure on said partition, such that fluid flow rate from said second chamber at any time is maintained within predetermined minimum and maximum values.

29. A method as in claim 28 wherein said parameter detected and measured by said sensor comprises a physical, chemical or biological parameter.

30. A method as in claim 29 wherein said parameter comprises at least one of fluid pressure within said first chamber or said second chamber, fluid pressure at an exit of said fluid outlet, concentration of a component of said fluid, pressure drop across said partition, temperature within said reservoir, volume of said fluid within said second chamber, volume rate of discharge of said fluid from said second chamber or said fluid outlet or strain in a wall of said reservoir.

31. A method as in claim 28 wherein said parameter exists at a location exteriorly of said device, said method further comprising disposing said sensor exteriorly of said device to detect and measure said parameter.

32. A method as in claim 31 wherein said parameter comprises a reaction condition of a chemical or biological reaction to which said fluid is dispensed, a bodily condition of a human being or animal to whom said fluid is being administered, an ambient environmental condition adjacent to said device, or a property of dispensed fluid at a location exteriorly of said device.

33. A method as in claim 28 wherein said second chamber contains a gas, a vapor or a vapor- or gas-emitting substance and said fluid dispensed from said second chamber comprises gas or vapor.

34. A method as in claim 28 wherein said second chamber contains a liquid or a liquid-emitting substance and said fluid dispensed from said second chamber comprises liquid.

35. A method as in claim 28 wherein said controller comprises a microprocessor.

36. A method as in claim 28 wherein said device comprises a syringe.

37. A method as in claim 28 wherein said device comprises a transdermal administration device.

38. A method as in claim 28 wherein said device comprises a fluid administration device for placement on, adjacent to or within a human or animal body, tissue, bone or organ.

39. A method as in claim 28 further comprising said fluid being dispensed comprising a fluid having pharmaceutical, physiological, curative, medicinal, homeopathic, nutritive or anesthetic properties when administered to a human being or animal.

40. A method as in claim 28 wherein said fluid is dispensed through an outlet conduit comprising an hollow tube or a vent.

41. A method as in claim 28 wherein at said outlet end of said hollow tube is disposed a hollow needle or cannula through which fluid dispensed from said device can be injected into a human or animal.

42. A method as in claim 28 wherein at said outlet end of said hollow tube is disposed an administration pad through which fluid dispensed from said device can be administered to a human or animal transdermally or by direct application to an organ, tissue or bone.

43. A method for dispensing fluid from a fluid-containing device comprising:

providing a fluid dispensing device comprising;

a housing having an internal fluid chamber comprising a gas chamber and a fluid chamber separated by a moveable pressure responsive partition, said fluid chamber having a fluid conduit providing fluid communication between said fluid liquid chamber and an outlet end of said conduit, said outlet end opening to an exterior of said housing;

pumping means comprising an electrochemical cell in gas communication with said gas chamber, for pumping gas into or out of said gas chamber, said gas when in said chamber exerting pressure against said pressure responsive partition causing responsive movement thereof of fluid in said liquid chamber, said responsive movement comprising said fluid moving toward and through said fluid conduit to said exterior of said housing or being withdrawn from said conduit into said liquid chamber;

controllable source of electric current for operation of said pumping means, said source connected to a controller for controlling said source to vary the amount and polarity of said electrical current to said pumping means and thereby operate said pumping means to change its rate or direction of pumping of said gas, said controller being responsive to a measurable parameter associated with said device; and

sensor means for detection and measurement of said parameter over time and generation of a signal to said controller indicating quantity and direction of any change in said parameter, said controller in response to said signal indicating said change in said parameter varying said electric current to said module to effect said change in rate of gas generation;

operating said sensor to detect and measure said change in said parameter and send a signal thereof to said controller;

operating said controller upon receipt of said signal to regulate said amount and polarity of said electrical current to said pumping means to increase or decease rate of pumping of said gas or change direction of pumping of said gas, such that fluid flow to or from said fluid chamber rate maintains a cumulative total of said fluid discharged from said fluid chamber to a target environment over a selected period of time to be within a predetermined range.

44. A method as in claim 43 wherein said parameter detected and measured by said sensor comprises a physical, chemical or biological parameter.

45. A method as in claim 44 wherein said parameter comprises at least one of fluid pressure within said gas chamber or said fluid chamber, fluid pressure at an exit of said fluid chamber, concentration of a component of said fluid, pressure drop across said partition, temperature within said reservoir, volume of said fluid within said fluid chamber, volume rate of discharge of said fluid from said fluid chamber or said fluid outlet or strain in a wall of said reservoir.

46. A method as in claim 44 wherein said parameter exists at a location exteriorly of said device, said method further comprising disposing said sensor exteriorly of said device to detect and measure said parameter.

47. A method as in claim 46 wherein said parameter comprises a reaction condition of a chemical or biological reaction to which said fluid is dispensed, a bodily condition of a human being or animal to whom said fluid is being administered, an ambient environmental condition adjacent to said device, or a property of dispensed fluid at a location exteriorly of said device.

48. A method as in claim 43 wherein said fluid chamber contains a gas, a vapor or a vapor- or gas-emitting substance and fluid dispensed from said fluid chamber comprises gas or vapor.

49. A method as in claim 43 wherein said fluid chamber contains a liquid or a liquid-emitting substance and said fluid dispensed from said fluid chamber comprises liquid.

50. A method as in claim 43 wherein said controller comprises a microprocessor.

51. A method as in claim 43 wherein said device comprises a syringe.

52. A method as in claim 43 wherein said device comprises a transdermal administration device.

53. A method as in claim 43 wherein said device comprises a fluid administration device for placement on, adjacent to or within a human or animal body, tissue, bone or organ.

54. A method as in claim 43 further comprising said fluid being dispensed comprising a fluid having pharmaceutical, physiological, curative, medicinal, homeopathic, nutritive or anesthetic properties when administered to a human being or animal.

55. A method as in claim 43 wherein said fluid is dispensed through an outlet conduit comprising an hollow tube or a vent.

56. A method as in claim 43 wherein at said outlet end of said hollow tube is disposed a hollow needle or cannula through which fluid dispensed from said device can be injected into a human or animal.

57. A method as in claim 43 wherein at said outlet end of said hollow tube is disposed an administration pad through which fluid dispensed from said device can be administered to a human or animal transdermally or by direct application to an organ, tissue or bone.