Reduced size implantable pump

• US 20060259016A1
• Filed: 05/10/2005
• Published: 11/16/2006
• Est. Priority Date: 05/10/2005
• Status: Active Grant

• Current Assignee: Aqulinx Medical, Inc.
• Original Assignee: Palyon Medical Corporation
• Inventors: Steinbach, Bernd
• Granted Patent: US 8,211,060 B2
• Time in Patent Office: Days
• US Class Current: 604/891.100
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• CPC Class Codes: A61M 5/141 with capillaries for restricting fluid flow
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/14586 pressurised by means of a flexible diaphragm
• CPC Class Codes: A61M 5/16813 by controlling the degree of opening of the flow line

Abstract

A variable hydraulic resistor for use with implantable pumps is disclosed. The variable hydraulic resistor according to the present invention is particularly useful in varying the flow rate of a medication fluid from an otherwise constant flow implantable pump. An implantable pump is also disclosed, which does not require a complicated clinching system or the like, and which may include an undulating membrane and chamber design to reduce the height of the pump.

Claims

1. An implantable device for dispensing an active substance to a patient comprising:

a housing defining an active substance chamber in fluid communication with an outlet for delivering said active substance to a target site within said patient, and a propellant chamber adjacent said active substance chamber; and

,

an undulating flexible membrane separating said active substance and propellant chambers,

wherein said active substance chamber has an undulating surface including a central convex portion flanked by at least two concave portions, said undulating surface cooperating with said undulating flexible membrane.

2. The implantable device according to claim 1, wherein the propellant chamber contains a propellant capable of expanding isobarically, the propellant cooperating with said flexible membrane to reduce the volume of the active substance chamber upon expansion of the propellant.

3. The implantable device according to claim 2, wherein the cooperating undulating surface of said active substance chamber and said undulating flexible membrane meet upon complete expansion of the propellant.

4. The implantable device according to claim 1, further comprising a replenishment opening in said housing in fluid communication with the active substance chamber, and a first septum sealing the opening.

5. The implantable device according to claim 4, wherein said replenishment opening is located within said central convex portion of said undulating surface of said active substance chamber so as to lower the overall height of said housing of said implantable device.

6. The implantable device according to claim 4, further comprising an annular opening in said housing communicating with said outlet, and a second septum sealing the annular opening.

7. The implantable device according to claim 1, further comprising means for varying the flow rate of said active substance between said active substance chamber and said outlet.

8. The implantable device according to claim 7, wherein said means includes an elongated polymer filament having a cross sectional dimension, the filament capable of being elongated to reduce the cross sectional dimension.

9. The implantable device according to claim 8, further including a capillary in fluid communication between said chamber and said outlet, wherein the filament is located eccentrically within said capillary.

10. The implantable device according to claim 9, wherein the filament has a uniform cross section along its length.

11. The implantable device according to claim 9, wherein the filament has a non-uniform cross section along its length.

12. The implantable device according to claim 8, further comprising means for elongating the filament.

13. The implantable device according to claim 12, wherein said means for elongating the filament includes an axle driven by a motor.

14. The implantable device according to claim 7, wherein said means includes a first hollow cylinder having a threaded exterior surface and a second hollow cylinder having a threaded interior surface, said first hollow cylinder axially received within said second hollow cylinder, wherein the threaded exterior surface of the first cylinder engages the threaded interior surface of the second cylinder.

15. The implantable device according to claim 14, wherein the axial movement of the first cylinder with respect to the second cylinder varies the flow rate of said active substance.

16. The implantable device according to claim 7, wherein said means includes a hollow tubular element having a cross section that is capable of being varied.

17. The implantable device according to claim 16, further including a capillary in fluid communication between said chamber and said outlet, wherein the hollow tubular element is located eccentrically within said capillary.

18. The implantable device according to claim 7, wherein said means includes an elongate insert having a longitudinally varying cross section along its length.

19. The implantable device according to claim 7, further comprising means for controlling said means for varying the flow rate of said active substance between said chamber and said outlet.

20. The implantable device according to claim 19, wherein the means for controlling are wireless.

21. The implantable device according to claim 1, further comprising a capillary in fluid communication between said active substance chamber and said outlet, said capillary having an inner surface, and a flow control element received within said capillary, said element having an outer surface opposing said inner surface of said capillary defining therebetween a passageway for the flow of said active substance therethrough, said outer surface of said element moveable relative to said inner surface of said capillary to alter the flow of said active substance therethrough.

22. The implantable device according to claim 1, wherein said housing includes two portions, the two portions being constructed so as to screw together.

23. The implantable device according to claim 22, wherein the two portions of said housing are constructed of PEEK.

24. The implantable device according to claim 1, wherein said housing further comprises a top portion and a bottom portion, said top portion being capable of engaging said bottom portion.

25. The implantable device according to claim 24, wherein said top portion and said bottom portion are screwed together.

26. The implantable device according to claim 24, wherein said top portion and said bottom portion capture said membrane therebetween.

27. The implantable device according to claim 26, wherein said top portion and said bottom portion form means for retaining said membrane therebetween.

28. The implantable device according to claim 26, wherein said housing further comprises a locking portion which may be screwed into either said top portion or said bottom portion to retain said top portion and said bottom portion together.

29. The implantable device according to claim 28, wherein said housing further comprises a septum retaining member for retaining a replenishment septum covering a replenishment opening.

30. An implantable device for dispensing an active substance to a patient comprising:

a housing defining a chamber and an outlet in fluid communication with the chamber for delivering said active substance to a target site within said patient, said housing having a first portion and a second portion,

wherein the first portion and the second portion are constructed of PEEK and screwed together.

31. The implantable device according to claim 30, wherein the chamber includes an active substance chamber in fluid communication with said outlet and a propellant chamber, the active substance and propellant chambers being separated by an undulating flexible membrane.

32. The implantable device according to claim 31, wherein said active substance chamber has an undulating surface which cooperates with said undulating flexible membrane.

33. The implantable device according to claim 32, wherein the propellant chamber contains a propellant capable of expanding isobarically, the propellant cooperating with said flexible membrane to reduce the volume of the active substance chamber upon expansion of the propellant.

34. The implantable device according to claim 33, wherein the cooperating undulating surface of said active substance chamber and said undulating flexible membrane meet upon complete expansion of the propellant.

35. The implantable device according to claim 30, further comprising a replenishment opening in said housing in fluid communication with the active substance chamber, and a first septum sealing the opening.

36. The implantable device according to claim 35, wherein said replenishment opening is located within said central convex portion of said undulating surface of said active substance chamber to lower the overall height of said housing of said implantable device.

37. The implantable device according to claim 36, further comprising an annular opening in said housing communicating with said outlet, and a second septum sealing the annular opening.

38. The implantable device according to claim 30, further comprising means for varying the flow rate of said active substance between said active substance chamber and said outlet.

39. The implantable device according to claim 38, wherein said means includes an elongated polymer filament having a cross sectional dimension, the filament capable of being elongated to reduce the cross sectional dimension.

40. The implantable device according to claim 39, further including a capillary in fluid communication between said chamber and said outlet, wherein the filament is located eccentrically within said capillary.

41. The implantable device according to claim 40, wherein the filament has a uniform cross section along its length.

42. The implantable device according to claim 40, wherein the filament has a non-uniform cross section along its length.

43. The implantable device according to claim 39, further comprising means for elongating the filament.

44. The implantable device according to claim 43, wherein said means for elongating the filament includes an axle driven by a motor.

45. The implantable device according to claim 38, wherein said means includes a first hollow cylinder having a threaded exterior surface and a second hollow cylinder having a threaded interior surface, said first hollow cylinder axially received within said second hollow cylinder, wherein the threaded exterior surface of the first cylinder engages the threaded interior surface of the second cylinder.

46. The implantable device according to claim 45, wherein the axial movement of the first cylinder with respect to the second cylinder varies the flow rate of said active substance.

47. The implantable device according to claim 38, wherein said means includes a hollow tubular element having a cross section that is capable of being varied.

48. The implantable device according to claim 47, further including a capillary in fluid communication between said chamber and said outlet, wherein the hollow tubular element is located eccentrically within said capillary.

49. The implantable device according to claim 38, wherein said means includes an elongate insert having a longitudinally varying cross section along its length.

50. The implantable device according to claim 38, further comprising means for controlling said means for varying the flow rate of said active substance between said chamber and said outlet.

51. The implantable device according to claim 50, wherein the means for controlling are wireless.

52. The implantable device according to claim 30, further comprising a capillary in fluid communication between said active substance chamber and said outlet, said capillary having an inner surface, and a flow control element received within said capillary, said element having an outer surface opposing said inner surface of said capillary defining therebetween a passageway for the flow of said active substance therethrough, said outer surface of said element moveable relative to said inner surface of said capillary to alter the flow of said active substance therethrough.

53. An implantable device for dispensing an active substance comprising:

a housing including a top portion, a bottom portion and a locking portion, said housing defining a propellant chamber and an active substance chamber in fluid communication with an outlet; and

a membrane retained between said top and bottom portions, said membrane separating said active substance and propellant chambers,

wherein said top and bottom portions are placed together and said locking portion engages one of said top or bottom portions to retain said top and bottom portions together.

54. The implantable device according to claim 53, wherein said top and bottom portions form an attachment for retaining said membrane therebetween.

55. The implantable device according to claim 53, wherein the propellant chamber contains a propellant capable of expanding isobarically, the propellant cooperating with said flexible membrane to reduce the volume of the active substance chamber upon expansion of the propellant.

56. The implantable device according to claim 53, wherein said active substance chamber includes an undulating surface, wherein said undulating surface includes a central convex portion flanked by at least two concave portions.

57. The implantable device according to claim 56, further comprising a replenishment opening in said housing in fluid communication with the active substance chamber, and a first septum sealing the opening.

58. The implantable device according to claim 57, wherein said replenishment opening is located within said central convex portion of said undulating surface of said active substance chamber to lower the overall height of said housing of said implantable device.

59. The implantable device according to claim 58, further comprising an annular opening in said housing communicating with said outlet, and a second septum sealing the annular opening.

60. The implantable device according to claim 59, wherein said housing further comprises a septum retaining member for retaining said first septum.

61. The implantable device according to claim 53, wherein said top, bottom and locking portions are constructed from PEEK.

62. A method of assembling a reduced size implantable pump comprising:

placing together a top portion and a bottom portion to retain a membrane therebetween; and

screwing a locking portion into said top portion or said bottom portion to retain said top and bottom portions together.

63. The method according to claim 62, further comprising the steps of placing a first septum in said top portion and screwing a septum retaining member into said top portion to retain said first septum therein.

64. The method according to claim 63, further comprising the step of placing a second septum in said top portion.

65. The method according to claim 64, wherein said locking portion at least partially retains said second septum.

66. The method according to claim 64, further comprising the step of placing a barium filled o-ring into said top portion.