Flow restriction system and method for patient infusion device

• US 20040015131A1
• Filed: 07/16/2002
• Published: 01/22/2004
• Est. Priority Date: 07/16/2002
• Status: Active Grant

• Current Assignee: Insulet Corporation
• Original Assignee: Insulet Corporation
• Inventors: Wood, Timothy J., Flaherty, J. Christopher, Garibotto, John T., Gorman, William, Moroney, Richard Morgan III
• Granted Patent: US 7,018,360 B2
• Time in Patent Office: Days
• US Class Current: 604/123
• CPC Class Codes: A61M 2005/1402 Priming
• CPC Class Codes: A61M 2205/0266 Shape memory materials
• CPC Class Codes: A61M 2205/3592 using telemetric means, e.g. radio or optical transmission
• CPC Class Codes: A61M 2209/045 for filling, e.g. for filling reservoirs
• CPC Class Codes: A61M 5/003 Kits for diabetics
• CPC Class Codes: A61M 5/14248 of the skin patch type
• CPC Class Codes: A61M 5/38 using hydrophilic or hydrophobic filters

Abstract

A device for delivering fluid, such as insulin for example, to a patient. The device includes a flow path having an exit port assembly adapted to connect to a transcutaneous patient access tool, and a reservoir connected to the exit port assembly. The device also includes a flow restriction system having an air removal filter communicating with the flow path and allowing air to exit the flow path and preventing fluid from exiting the flow path, and a flow restrictor positioned within the flow path between the air removal filter and the exit port assembly. Among other features and advantages, the flow restriction system of the present invention allows the flow path of the fluid delivery device to be purged of air, or “primed” prior to operation, such that desired volumes of fluid can be accurately delivered by the device.

Claims

1. A device for delivering fluid to a patient, comprising:

A) a flow path including,

an exit port assembly adapted to connect to a transcutaneous patient access tool, and

a reservoir connected to the exit port assembly; and

B) a flow restriction system including,

an air removal filter communicating with the flow path and allowing air to exit the flow path and preventing fluid from exiting the flow path, and

a flow restrictor positioned within the flow path between the air removal filter and the exit port assembly.

2. A device according to claim 1, wherein the flow restrictor of the flow restriction system comprises an outlet plug removably connected to the exit port assembly to prevent fluid from exiting the flow path through the exit port assembly.

3. A device according to claim 2, wherein the exit port assembly includes a transcutaneous patient access tool and the outlet plug is removably connected to the access tool.

4. A device according to claim 3, wherein the transcutancous patient access tool comprises a needle having a distal end for insertion into a patient and the outlet plug is removably connected to the distal end of the needle.

5. A device according to claim 2, wherein the air removal filter of the flow restriction system comprises at least a portion of the outlet plug allowing air to exit the flow path through the exit port assembly.

6. A device according to claim 2, wherein the exit port assembly includes a transcutaneous patient access tool comprising a needle having a distal end for insertion into a patient and the outlet plug comprises:

a sleeve having a first end removably received in a substantially fluid-tight manner on the distal end of the needle; and

a cap connected to a second end of the sleeve.

7. A device according to claim 6, wherein the sleeve and the cap of the outlet plug are unitarily formed from a resiliently flexible material.

8. A device according to claim 6, wherein the air removal filter is seated in the cap of the outlet plug and prevents fluid from passing out of the needle and allows air to pass out of the needle.

9. A device according to claim 8, wherein the air removal filter of the outlet plug comprises one of PTFE and polyethylene.

10. A device according to claim 8, wherein the air removal filter of the outlet plug is provided with predetermined physical properties such that the filter expands upon the flow path being substantially primed.

11. A device according to claim 10, wherein the air removal filter includes visual indicia for indicating when the flow path is substantially primed.

12. A device according to claim 11, wherein the visual indicia comprises a drawing on the filter that changes shape upon the filter expanding.

13. A device according to claim 8, wherein the air removal filter of the outlet plug is adapted to allow fluid to pass out of the needle upon a pressure within the flow path exceeding a desired maximum level of flow path pressure.

14. A device according to claim 8, wherein the air removal filter of the outlet plug includes:

an outer layer; and

an inner layer having predetermined physical properties that allow the inner layer to expand to contact the outer layer upon the flow path being substantially primed.

15. A device according to claim 14, wherein the outer layer of the air removal filter is relatively transparent and the inner layer of the air removal filter is darker in coloring than the outer transparent layer such that the inner layer can be seen through the outer layer when the inner layer contacts the outer layer.

16. A device according to claim 14, wherein the flow restriction system further includes a filter sensor for providing a signal when the inner layer contacts the outer layer.

17. A device according to claim 8, wherein the air bubble removal filter of the outlet plug is comprised of needle septum material.

18. A device according to claim 2, wherein the outlet plug further comprises a needle septum.

19. A device according to claim 2, wherein the outlet plug includes a pressure relief valve actuable upon a pressure within the flow path exceeding a desired maximum level of flow path pressure.

20. A device according to claim 2, further comprising:

a housing containing the flow path, wherein the exit port assembly extends at least partly through a port in the housing;

an adhesive layer provided in at least one continuous band on an exterior surface of the housing surrounding the port of the housing; and

a protective layer removably covering the adhesive layer, wherein the outlet plug of the flow restriction system is secured to the protective layer so that removal of the protective layer removes the outlet plug from the exit port assembly.

21. A device according to claim 2, further comprising a switch arranged to be closed upon removal of the outlet plug from the exit port assembly.

22. A device according to claim 2, wherein the outlet plug includes a handle for supporting the fluid delivery device during filling of the device through the fill port.

23. A device according to claim 22, wherein the handle of the outlet plug includes an outer contour that nests with an outer contour of the fluid delivery device.

24. A packaging system including a device according to claim 2, and further including:

a container holding the fluid delivery device; and

a protective cover removably sealing the fluid delivery device within the container, wherein the outlet plug of the flow restriction system is secured to the protective cover so that removal of the protective cover from the container removes the outlet plug from the exit port assembly.

25. The packaging system of claim 24, wherein the container includes an inner contour that nests with an outer contour of the fluid delivery device.

26. The packaging system of claim 24, wherein the fluid delivery device includes a switch and the protective cover includes an insert extending into the fluid delivery device to normally hold the switch open.

27. A device according to claim 1, wherein the flow path further comprises a fill port connected to the reservoir.

28. A device according to claim 27, wherein the fill port includes a resealing needle septum.

29. A device according to claim 27, further comprising:

a housing containing the flow path, wherein the fill port extends at least partly through a port of the housing; and

an adhesive layer provided in at least one continuous band on an exterior surface of the housing surrounding the port of the housing.

30. A device according to claim 27, wherein the flow restrictor and the air removal filter of the flow restriction system are positioned between the reservoir and the outlet port assembly.

31. A device according to claim 27, wherein the flow restriction system further comprises a second air removal filter positioned between the fill port and the reservoir.

32. A device according to claim 31, wherein the flow restriction system further comprises a second flow restrictor positioned between the second air removal filter and the reservoir.

33. A device according to claim 31, wherein the second air bubble removal filter comprises one of PTFE and polyethylene.

34. A device according to claim 31, wherein the second air bubble removal filter comprises one of PTFE and polyethylene.

35. A device according to claim 1, wherein the flow restriction system further includes a sensor assembly monitoring fluid flow conditions within the flow path.

36. A device according to claim 35, wherein the sensor assembly of the flow restriction system is positioned at an end of the reservoir.

37. A device according to claim 35, wherein the flow path includes a passageway providing fluid communication between the reservoir and the exit port assembly, and the sensor assembly of the flow restriction system is positioned against the passageway.

38. A device according to claim 35, wherein the sensor assembly of the flow restriction system comprises:

a resilient diaphragm having opposing first and second surfaces, with the first surface of the diaphragm positioned against the flow path;

a chamber wall positioned adjacent the second surface of the diaphragm and defining a sensor chamber adjacent the second surface of the diaphragm; and

at least one sensor arranged to provide a signal when the second surface of the diaphragm expands into the chamber.

39. A device according to claim 38, wherein the sensor comprises a switch positioned within the chamber such that the second surface of the diaphragm closes the switch upon expanding into the chamber.

40. A device according to claim 38, wherein the sensor is responsive to one of contact, pressure, light, magnetism, strain, and density.

41. A device according to claim 38, wherein the sensor is positioned on a portion of the chamber wall furthest from the flow path and the enclosed chamber has a predetermined volume.

42. A device according to claim 38, wherein the sensor comprises a circuit having a lead positioned on the second surface of the diaphragm and a lead positioned on the chamber wall such that the leads come together and close the circuit when the second surface of the diaphragm expands into the chamber.

43. A device according to claim 38, wherein the sensor comprises a circuit having leads positioned on the chamber wall and a conductive layer positioned on the second surface of the diaphragm such that the conductive layer contacts the leads to close the circuit when the second surface of the diaphragm expands into the chamber in response to the predetermined fluid flow condition.

44. A device according to claim 38, wherein the diaphragm comprises a thin, flat piece of flexible and resilient material.

45. A device according to claim 38, wherein the sensor chamber has a predetermined volume.

46. A device according to claim 38, wherein the flow restriction system includes an alarm connected to the sensor.

47. A device according to claim 46, wherein the alarm comprises an audible alarm.

48. A device according to claim 46, wherein the alarm comprises a visual alarm.

49. A device according to claim 38, further comprising a processor connected to the sensor of the sensor assembly.

50. A device according to claim 49, further comprising an alarm connected to the processor.

51. A device according to claim 50, wherein the alarm comprises an audible alarm.

52. A device according to claim 50, wherein the alarm comprises a visual alarm.

53. A device according to claim 50, wherein the processor is programmed to activate the alarm upon receiving a signal from the sensor.

54. A device according to claim 50, wherein the processor is programmed to activate the alarm upon receiving a signal from the sensor indicative of a predetermined pressure.

55. A device according to claim 50, wherein the processor is programmed to activate the alarm upon not receiving a signal from the sensor indicative of a predetermined pressure.

56. A device according to claim 49, wherein the processor is programmed to provide a signal indicative of a desired pressure within the flow path upon receiving a signal from the sensor.

57. A device according to claim 50, wherein the processor is programmed to provide a signal indicative of an undesired pressure within the flow path upon receiving a signal from the sensor.

58. A device according to claim 49, wherein the processor is programmed to provide a signal indicative of a desired pressure within the flow path upon receiving multiple signals from the sensor.

59. A device according to claim 49, wherein the sensor assembly is adapted to provide a signal to the processor when the flow path is primed.

60. A device according to claim 38, wherein a combined volume of the flow path is fixed and predetermined, and wherein possible expansion of the combined volume is relatively small compared with the volume of the sensor chamber.

61. A device according to claim 1, wherein the reservoir contains a therapeutic fluid.

62. A device according to claim 61, wherein the therapeutic fluid is insulin.

63. A device according to claim 1, wherein a combined volume of the flow path is fixed and predetermined.

64. A device according to claim 1, wherein the reservoir is non-pressurized.

65. A device according to claim 1, wherein the reservoir includes a side wall extending towards an outlet connected to the exit port assembly, a plunger movably received within the side wall of the reservoir for forcing fluid through the outlet upon moving along the side wall, and wherein the device includes a dispenser for causing the plunger to move along the side wall of the reservoir, and a local processor connected to the dispenser and programmed to cause the dispenser to move the plunger based on flow instructions.

66. A device according to claim 65, wherein the dispenser includes an elongated shape memory element connected to the local processor and having a changeable length decreasing from an uncharged length to a charged length when at least one charge is applied to the shape memory element, the shape memory element connected to the plunger such that the changeable length of the shape memory element causes the plunger to move along the side wall of the reservoir.

67. A device according to claim 66, wherein the reservoir further includes:

a threaded lead screw extending from the plunger and prevented from rotating about a longitudinal axis of the lead screw; and

a rotatable gear threadedly engaging the threaded lead screw such that rotation of the gear in at least one direction causes longitudinal movement of the threaded lead screw and the plunger along the side wall of the reservoir towards the outlet of the reservoir; and

the dispenser further includes a finger for engaging radially extending teeth of the gear, wherein the finger and the teeth are adapted such that linear movement of the finger in a first direction adjacent the gear causes rotation of the gear while linear movement of the finger in a second direction adjacent the gear causes no rotation of the gear, and the elongated shape memory element is connected to the finger such that the changeable length of the shape memory element decreasing from an uncharged length to a charged length causes linear movement of the finger in one of the first and the second directions.

68. A device according to claim 67, wherein the dispenser further includes an actuation element connected to the finger for causing linear movement of the finger in the first direction.

69. A device according to claim 68, wherein the actuation element comprises a spring.

70. A device according to claim 1, further comprising:

a dispenser for causing fluid from the reservoir to flow through the flow path to the exit port assembly;

a local processor connected to the dispenser and programmed to cause fluid flow to the exit port assembly based upon flow instructions;

a wireless receiver connected to the local processor for receiving flow instructions from a separate, remote control device and delivering the flow instructions to the local processor; and

a housing containing the flow path, the dispenser, the local processor, and the wireless receiver, wherein the housing is free of user input components for providing flow instructions to the local processor.

71. A system including a fluid delivery device according to claim 70, and further comprising a remote control device separate from the fluid delivery device and including:

a remote processor;

user interface components connected to the remote processor for allowing a user to provide flow instructions to the remote processor; and

a transmitter connected to the remote processor for transmitting the flow instructions to the receiver of the fluid delivery device.

72. A device according to claim 1, further comprising:

a dispenser for causing fluid from the reservoir to flow through the flow path to the exit port assembly;

a local processor connected to the dispenser and programmed to cause fluid flow to the exit port assembly based upon flow instructions, and further programmed to provide flow information;

a wireless transmitter connected to the local processor for transmitting the flow information from the local processor to a separate, remote control device; and

a housing containing the flow path, the dispenser, the local processor, and the wireless transmitter, wherein the housing is free of user output components for providing the flow information from the local processor to a user.

73. A system including a fluid delivery device according to claim 72 and further comprising a remote control device separate from the fluid delivery device and including:

a remote processor;

user output components connected to the remote processor for allowing a user to receive flow information; and

a receiver connected to the remote processor for receiving the flow information from the transmitter of the fluid delivery device.

74. A system according to claim 73, wherein the remote control device includes an alarm connected to the remote processor.

75. A device according to claim 2, wherein the exit port assembly includes tubing extending to a medical device fitting and the outlet plug is removably connected to the fitting.

77. A method according to claim 74, for use a fluid delivery device having a flow path further including a reservoir connected to the exit port assembly and a fill port connected to the reservoir, wherein the method further comprises:

allowing air to exit the flow path at a second air removal point within the flow path located between the fill port and the reservoir; and

restricting fluid flow between the second air removal point and the reservoir.

76. A method for restricting fluid flow in a flow path of a fluid delivery device having an exit port assembly adapted to connect to a transcutaneous patient access tool, the method comprising:

preventing fluid from exiting the flow path;

allowing air to exit the flow path at an air removal point within the flow path; and

restricting fluid flow through the flow path between the air removal point and the exit port assembly.

78. A method according to claim 76, further comprising indicating when the flow path is substantially primed.

79. A method according to claim 76, further comprising indicating when fluid pressure in the flow path rises to a predetermined level.

80. A method according to claim 76, further comprising indicating when fluid pressure in the flow path exceeds a predetermined level.

81. A method according to claim 76, wherein fluid flow is restricted at a distal end of the exit port assembly.

82. A method according to claim 76, wherein the air removal point is located at a distal end of the exit port assembly.

83. A method according to claim 76, wherein the exit port assembly of the fluid delivery device includes a transcutaneous patient access tool comprising a needle having a distal end, and the air removal point is located at the distal end of the needle.