Controlled release device and method using electrothermal ablation

• US 20040121486A1
• Filed: 08/15/2003
• Published: 06/24/2004
• Est. Priority Date: 08/16/2002
• Status: Active Grant

• Current Assignee: DARE MB Incorporated
• Original Assignee: MicroCHIPS Inc.
• Inventors: Sheppard, Norman F. Jr., Maloney, John M., Uhland, Scott A., Yomtov, Barry Y., Herman, Stephen J., Polito, Benjamin F.
• Granted Patent: US 7,510,551 B2
• Time in Patent Office: Days
• US Class Current: 436/174
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61M 2005/1726 the body parameters being measured at, or proximate to, the infusion site
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 2205/123 with incorporated reservoirs
• CPC Class Codes: A61M 2205/3653 by Joule effect, i.e. electric resistance
• CPC Class Codes: A61M 25/0069 Tip not integral with tube
• CPC Class Codes: A61M 25/0082 Catheter tip comprising a tool
• CPC Class Codes: A61M 37/00 Other apparatus for introducing media into the body for reproduction or fertilisation A61B17/425; apparatus for iontophoresis or cataphoresis A61N1/30; Percutany, i.e. introducing medicines into the body by diffusion through the skin salt baths A61H33/04
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61N 1/32 alternating or intermittent currents applying electric fields by inductive or capacitive coupling A61N1/40; microwave apparatus A61N5/02
• CPC Class Codes: Y10T 436/25 including sample preparation

Abstract

Devices and methods are provided for the controlled release or exposure of reservoir contents. The device includes a reservoir cap formed of an electrically conductive material, which prevents the reservoir contents from passing out from the device and prevents exposure of the reservoir contents to molecules outside of the device; an electrical input lead connected to said reservoir cap; and an electrical output lead connected to said reservoir cap, such that upon application of an electrical current through the reservoir cap, via the input lead and output lead, the reservoir cap ruptures to release or expose the reservoir contents. The reservoir contents can comprise a release system containing drug molecules for release or can comprise a secondary device, such as a sensor. In one embodiment, the controlled release system is incorporated into an implantable drug delivery device.

Claims

1. A device for the controlled release or exposure of reservoir contents comprising:

a reservoir cap formed of an electrically conductive material, which prevents the reservoir contents from passing out from the device and prevents exposure of the reservoir contents to molecules outside of the device;

an electrical input lead connected to said reservoir cap; and

an electrical output lead connected to said reservoir cap, such that upon application of an electrical current through the reservoir cap, via the input lead and output lead, the reservoir cap is ruptured to release or expose the reservoir contents.

2. The device of claim 1, further comprising a source of electric power for applying the electrical current.

3. The device of claim 1, wherein the application of electrical current through the reservoir cap causes the temperature of the reservoir cap to increase preferentially compared to the temperature of the leads.

4. The device of claim 1, wherein the reservoir cap is formed of a material having a melting point which differs from the melting point of the material forming the leads.

5. The device of claim 1, wherein the reservoir cap and leads are formed of the same material, and the reservoir cap has a smaller cross-sectional area in the direction of electric current flow.

6. The device of claim 5, wherein the leads and the reservoir cap have the same thickness, and the ratio of the width of the leads to the width of the reservoir cap is 2:

1 or more.

7. The device of claim 5, wherein the reservoir cap has a thickness that is less than the thickness of the leads.

8. The device of claim 7, wherein the ratio of the thickness of the leads to the thickness of the reservoir cap is 2:

1 or more.

9. The device of claim 1, wherein the reservoir cap is formed of a material which is different from the material forming the leads.

10. The device of claim 9, wherein the reservoir cap is formed of a material having a different resistivity than the material forming the leads.

11. The device of claim 9, wherein the reservoir cap is formed of a material having a different thermal diffusivity or thermal conductivity than the material forming the leads.

12. The device of claim 1, wherein the reservoir cap comprises a metal film.

13. The device of claim 12, wherein the metal film comprises of a metal selected from the group consisting of gold, platinum, titanium, copper, aluminum, silver, gold/silicon alloys, gold/germanium alloys, platinum/iridium, nickel/titanium, and platinum silicide.

14. The device of claim 1, wherein the reservoir cap comprises multiple layers of metal or multiple layers of metal and semiconductor.

15. The device of claim 1, further comprising one or more layers of a dielectric material on at least a portion of the reservoir cap, the leads, or both.

16. The device of claim 15, wherein the dielectric material comprises oxides, nitrides, carbides, diamond, fluorocarbon films, or combinations thereof.

17. The device of claim 1, wherein the reservoir contents are located in two or more reservoirs provided in a substrate.

18. The device of claim 1, wherein the reservoir contents comprises at least one therapeutic or prophylactic agent.

30. The device of claim 1, which is a subcomponent of an implantable drug delivery device.

31. The device of claim 30, further comprising at least one sensor indicative of a physiological condition, at least one electrode for providing electrical stimulation to the body, a catheter, a pump, or a combination thereof.

32. The device of claim 1, which is part of a microchip device.

50. The device of claim 1, which is part of an implantable catheter.

19. A device for the controlled release or exposure of reservoir contents comprising:

a substrate;

a plurality of reservoirs provided in the substrate;

reservoir contents comprising molecules, a secondary device, or both, located in said plurality of reservoirs;

a reservoir cap covering each reservoir to isolate said reservoir contents within said reservoir, each reservoir cap comprising an electrically conductive material;

a pair of conductive leads electrically connected to said reservoir cap, the pair comprising an electrical input lead and an electrical output lead; and

a source of electric power for applying an electrical current through each reservoir cap, via said pair of conductive leads, in an amount effective to rupture the reservoir cap.

20. The device of claim 19, comprising four or more reservoirs positioned in a two-dimensional array in the substrate.

21. The device of claim 20, wherein the input leads to the reservoir caps are electrically connected in parallel by rows of the array and the output leads from the reservoir caps are electrically connected in parallel by columns of the array.

22. The device of claim 19, further comprising an electrical component or system for detecting an open electrical circuit between the leads of a reservoir cap that has been ruptured, to verify reservoir opening.

23. The device of claim 19, wherein the reservoir contents comprises a release system comprising drug molecules.

24. The device of claim 19, further comprising activation means for controlling said application of electric current through each reservoir cap.

25. The device of claim 24, wherein said activation means comprises a microprocessor or state machine.

26. The device of claim 24, wherein said activation means comprises an active electronic component effective to eliminate unintended reservoir opening.

27. The device of claim 26, wherein the active electronic component comprises a diode or transistor.

28. The device of claim 19, wherein the substrate is in a shape selected from the group consisting of disks, cylinders, or spheres.

29. The device of claim 19, wherein a dielectric material is interposed between the reservoir cap and the substrate to thermally isolate the reservoir cap from the substrate.

40. A method for the controlled delivery of molecules comprising:

positioning at a preselected location the device of claim 19 wherein the reservoir contents comprises molecules for delivery; and

applying an electrical current through said reservoir cap, via the electrical input lead and the electrical output leads, to rupture the reservoir cap to enable the molecules to pass outward from the device to the preselected location.

43. A method for the controlled exposure of reservoir contents comprising:

positioning at a preselected location the device of claim 19 wherein the reservoir contents comprises a secondary device; and

applying an electrical current through said reservoir cap, via the electrical input lead and the electrical output leads, to rupture the reservoir cap to expose the secondary device to molecules at the preselected location.

33. A device to provide the controlled release of a drug contained therein to a body of a human or animal comprising:

a reservoir cap formed of an electrically conductive material, which prevents the drug from passing out from the device to the body;

a pair of conductive leads electrically connected to said reservoir cap, the pair comprising an electrical input lead and an electrical output lead; and

activation means for selectively applying an electrical current through said reservoir cap, via the input lead and output lead, to locally heat the reservoir cap causing the reservoir cap to rupture to enable the drug to pass outward from the device to the body.

34. The device of claim 33, further comprising at least one reservoir for containing the drug, said reservoir being at least partially enclosed by the reservoir cap.

35. The device of claim 34, comprising a plurality of reservoirs and a plurality of reservoir caps.

36. A method for the controlled delivery of molecules comprising:

positioning at a preselected location a device which provides the controlled release of molecules, the device having the molecules for delivery and a reservoir cap formed of an electrically conductive material which prevents said molecules for delivery from passing out from the device; and

applying an electrical current through said reservoir cap, via an electrical input lead and an electrical output lead which are electrically connected to said reservoir cap, to rupture the reservoir cap to enable the molecules to pass outward from the device to the preselected location.

37. The method of claim 36, wherein the preselected location is internal to a patient in need of the molecules.

38. The method of claim 36, wherein the molecules comprise a release system comprising drug molecules.

39. The method of claim 36, wherein said application of electrical current through the reservoir cap causes the temperature of the reservoir cap to increase preferentially compared to the temperature of the leads.

42. The method of claim 39, wherein the preselected location is internal to a patient and the reservoir contents comprises a sensor or sensor component.

41. A method for the controlled exposure of reservoir contents comprising:

positioning at a preselected location a device which provides controlled exposure of reservoir contents, the device having reservoir contents and a reservoir cap formed of an electrically conductive material which prevents exposure of the reservoir contents to molecules outside of the device at the preselected location; and

applying an electrical current through said reservoir cap, via an electrical input lead and an electrical output lead which are electrically connected to said reservoir cap, to rupture the reservoir cap to expose the reservoir contents to said molecules at the preselected location.

44. A method of fabricating a device for the controlled exposure or release of molecules or secondary devices comprising:

forming a plurality of reservoirs in a substrate;

capping each of said reservoirs with an electrically conductive reservoir cap;

forming in operable connection with each reservoir cap an electrical input lead and an electrical output lead; and

providing an electrical current supply and distribution means capable of selectively passing an electrical current through each reservoir cap, via the input lead and output lead, in an amount effective to rupture the reservoir cap.

45. The method of claim 44, wherein the leads and the reservoir cap are formed of the same material in the same step.

46. The method of claim 44, further comprising coating the reservoir cap, the leads, or both, with a dielectric material.

47. The method of claim 44, further comprising forming a layer of a dielectric material on the substrate, wherein the dielectric material is interposed between the reservoir cap and the substrate to thermally isolate the reservoir cap from the substrate.

48. The method of claim 44, further comprising loading the reservoirs with reservoir contents.

49. The method of claim 48, wherein the reservoir contents comprises a release system comprising drug molecules.