DRUG-DELIVERY PUMPS AND METHODS OF MANUFACTURE

• US 20090312742A1
• Filed: 05/08/2009
• Published: 12/17/2009
• Est. Priority Date: 05/08/2008
• Status: Active Grant

• Current Assignee: MiniPumps, LLC
• Original Assignee: MiniPumps, LLC
• Inventors: Tai, Yu-Chong, Shih, Jason, Humayun, Mark, Caffey, Sean, Pang, Changlin, Jiang, Fukang
• Granted Patent: US 8,231,608 B2
• Time in Patent Office: Days
• US Class Current: 604/500
• CPC Class Codes: A61F 9/0017 implantable in, or in contact with, the eye, e.g. ocular inserts
• CPC Class Codes: A61F 9/00781 Apparatus for modifying intraocular pressure, e.g. for glaucoma treatment drainage implants in general A61M27/002
• 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 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 2210/0612 Eyes
• CPC Class Codes: A61M 39/24 Check- or non-return valves
• CPC Class Codes: A61M 5/1408 in parallel, e.g. manifolds, sequencing valves access sites A61M39/02; tube connectors A61M39/10
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/14593 the diaphragm being actuated by fluid pressure
• CPC Class Codes: A61M 5/16886 for measuring fluid flow rate, i.e. flowmeters
• CPC Class Codes: B44C 1/227 by etching
• CPC Class Codes: Y10T 156/1092 All laminae planar and face to face
• CPC Class Codes: Y10T 156/1093 with covering of discrete laminae with additional lamina

Abstract

Embodiments of an implantable electrolytic pump include a first expandable diaphragm and a second flexible diaphragm, and first and second chambers each for containing a fluid, wherein the first expandable diaphragm separates the first and second chambers and provides a fluid barrier therebetween, and the second chamber is formed between the first expandable diaphragm and the second flexible diaphragms. The pump may further include electrolysis electrodes within the first chamber for causing generation of a gas therein and to thereby expand the expandable diaphragm so that fluid is forced from the second chamber into a cannula.

Claims

1. An implantable electrolytic pump comprising:

a first expandable diaphragm and a second flexible diaphragm;

first and second chambers each for containing a fluid, wherein the first expandable diaphragm separates the first and second chambers and provides a fluid barrier therebetween, and the second chamber is formed between the first expandable diaphragm and the second flexible diaphragm;

a perforated shell over the second flexible diaphragm;

a cannula for conducting liquid from the second chamber; and

electrolysis electrodes within the first chamber for causing generation of a gas therein and to thereby expand the expandable diaphragm so that fluid is forced from the second chamber into the cannula, whereby body fluid is admitted through the shell perforations to relieve vacuum pressure on the second chamber.

2. The pump of claim 1, wherein the perforated shell is substantially rigid.

3. The pump of claim 1, wherein the perforated shell comprises or consists essentially of at least one of a biocompatible plastic material or a metal.

4. The pump of claim 1, further comprising a casing.

5. The pump of claim 4, wherein the perforated shell forms part of the casing.

6. The pump of claim 4, wherein the casing comprises or consists essentially of a material selected from the group consisting of a ceramic, an epoxy encapsulation, a metal, polyetheretherketone (PEEK), polypropylene, polydimethylsiloxane (PDMS), and parylene.

7. The pump of claim 6, wherein the metal comprises or consists essentially of titanium, niobium, or nitinol.

8. The pump of claim 4, wherein the casing is at least partially coated with parylene.

9. The pump of claim 1, wherein the perforated shell has a thickness of greater than 0.1 mm.

10. The pump of claim 1, wherein the perforated shell comprises a plurality of perforations for allowing a body fluid to flow therethrough.

11. The pump of claim 10, wherein the perforations are sized and shaped to allow a body fluid to flow therethrough at a sufficient rate to substantially offset a vacuum pressure applied to the second flexible diaphragm.

12. The pump of claim 1, further comprising at least one refill port.

13. The pump of claim 1, wherein the diaphragms comprise or consist essentially of parylene or a composite material.

14. The pump of claim 13, wherein the composite material is platinum and parylene.

15. The pump of claim 1, further comprising circuitry, disposed below the first chamber and electrically connected to the electrodes, for operating the electrodes.

16. The pump of claim 15, wherein the circuitry adjustably controls a flow rate from the second chamber.

17. The pump of claim 15, wherein the circuitry comprises at least one of a data storage means, a data transmission means, or a data receiving means.

18. The pump of claim 17, wherein the data transmission means comprises a wireless telemetry circuit.

19. The pump of claim 17, wherein the circuitry is secured to the electrodes by a conductive epoxy.

20. The pump of claim 19, wherein the conductive epoxy comprises or consists essentially of a biocompatible material.

21. The pump of claim 20, wherein the biocompatible material comprises or consists essentially of gold or silver.

22. The pump of claim 15, wherein the circuitry provides an adjustable current or voltage to the electrolysis electrodes to adjustably control a flow rate from the second chamber.

23. The pump of claim 1, wherein the electrolysis electrodes comprise or consist essentially of at least one of platinum, gold, or silver on parylene, ceramic, or a biocompatible insulator.

24. The pump of claim 1, wherein at least one of the expandable membranes comprises corrugations.

25. The pump of claim 1, wherein at least one of the expandable membranes comprises perimeter bellows folds.

26. The pump of claim 1, wherein the first chamber contains at least one fluid that evolves gas upon activation of the electrolysis electrodes.

27. The pump of claim 26, wherein the gas returns to a liquid state upon deactivation of the electrolysis electrodes.

28. The pump of claim 26, wherein the at least one fluid comprises a saline solution, a solution comprising magnesium sulfate, a solution comprising sodium sulfate, or pure water.

29. The pump of claim 1, wherein the first chamber comprises a recombination catalyst.

30. The pump of claim 29, wherein the recombination catalyst comprises platinum.

31. The pump of claim 1, further comprising an osmotic diaphragm between the second flexible diaphragm and the perforated shell.

32. The pump of claim 31, wherein a third chamber is formed between the second flexible diaphragm and the osmotic diaphragm.

33. The pump of claim 32, wherein the osmotic diaphragm is at least partially anchored to the perforated shell.

34. The pump of claim 32, further comprising at least one osmosis chamber fluid within the third chamber.

35. The pump of claim 34, wherein the at least one osmosis chamber fluid comprises at least one solvent and at least one solute.

36. The pump of claim 34, wherein the fluid comprises a saline solution, a solution comprising magnesium sulfate, or a solution comprising sodium sulfate.

37. The pump of claim 32, further comprising a refill port in fluid communication with the third chamber.

38. The pump of claim 32, wherein the osmotic diaphragm allows a surrounding body fluid to flow into the third chamber at a sufficient rate to substantially offset a pressure applied to the second flexible diaphragm.

39. The pump of claim 1, wherein the perforated shell comprises an osmotic diaphragm.

40. The pump of claim 1, further comprising at least one of a check valve, a pressure sensor, or a flow sensor.

41. The pump of claim 40, wherein the at least one a check valve, pressure sensor, or flow sensor is located within the cannula.

42. The pump of claim 40, wherein the check valve prevents leakage of a fluid from the second chamber when the pump is at rest or during a refilling process.

43. The pump of claim 40, wherein the check valve prevents backward fluid flow through the cannula and into the second chamber.

44. The pump of claim 1, comprising a plurality of first chambers.

45. The pump of claim 44, comprising a plurality of second chambers above the plurality of first chambers.

46. The pump of claim 45, wherein each second chamber comprises a refill port.

47. The pump of claim 45, further comprising at least one cannula in fluid communication with each of the plurality of second chambers.

48. The pump of claim 44, further comprising separately controllable electrolysis electrodes within each of the plurality of first chambers.

49. The pump of claim 1, further comprising a plurality of cannulas in fluid communication with the second chamber.

50. The pump of claim 46, wherein each cannula comprises at least one of a check valve or sensor.

51. A method of administering a drug, the method comprising the steps of:

providing a pump comprising an electrolysis chamber, a drug chamber and a perforated shell thereover, the shell being in contact with a surrounding fluid; and

activating the electrolysis chamber to dispense a volume of drug from the drug chamber, whereby the drug chamber decreases in volume following drug dispensation, fluid being admitted through the shell perforations to offset the decreased volume of the drug chamber and prevent buildup of vacuum pressure thereon.

52. The method of claim 51, wherein the activating step comprises activating electrolysis electrodes within the electrolysis chamber for causing generation of a gas therein.

53. The method of claim 52, wherein the electrolysis chamber contains at least one liquid electrolyte which causes electrolysis of the gas.

54. The method of claim 53, wherein the gas returns to a substantially liquid state upon deactivation of the electrolysis electrodes.

55. The method of claim 51, wherein the electrolysis chamber comprises a recombination catalyst.

56. The pump of claim 55, wherein the recombination catalyst comprises platinum.

57. The method of claim 53, wherein the at least one fluid comprises a saline solution, a solution comprising magnesium sulfate, a solution comprising sodium sulfate, or pure water.

58. The method of claim 51, wherein the generation of a gas within the electrolysis chamber expands a first expandable diaphragm located between the electrolysis chamber and the drug chamber.

59. The method of claim 58, wherein the pump further comprises a second flexible diaphragm located between the drug chamber and the perforated shell.

60. The method of claim 59, wherein at least one of the first diaphragm and second diaphragm comprises or consists essentially of parylene or a composite material.

61. The method of claim 60, wherein the composite material comprises platinum and parylene.

62. The method of claim 51, wherein the perforated shell is substantially rigid.

63. The method of claim 51, wherein the perforated shell comprises at least one of a biocompatible plastic material or a metal.

64. The method of claim 63, wherein the perforations are sized and shaped to allow a body fluid to flow therethrough at a sufficient rate to substantially offset a vacuum pressure applied to the drug chamber.

65. The method of claim 51, wherein the pump further comprises an osmotic diaphragm between the drug chamber and the perforated shell to form an osmosis chamber between the drug chamber and the osmotic diaphragm, the osmotic diaphragm allowing a body fluid to flow therethrough into the osmosis chamber.

66. The method of claim 65, wherein the osmotic diaphragm is adapted to allow a body fluid to flow into the third chamber at a sufficient rate to substantially offset the decreased volume of the drug chamber.

67. The method of claim 51, wherein the drug is dispensed through at least one cannula in fluid communication with the drug chamber.

68. The method of claim 51, further comprising dispensing the drug through a plurality of cannulas in fluid communication with the drug chamber.

69. The method of claim 68, wherein each cannula comprises at least one of a check valve or sensor.

70. The method of claim 51, further comprising controlling the dispensing of the drug using at least one check valve.

71. The method of claim 51, further comprising monitoring the dispensing of the drug using at least one flow sensor.