Controlled release device and method using electrothermal ablation

• US 7,510,551 B2
• Filed: 08/15/2003
• Issued: 03/31/2009
• 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.
• Primary Examiner(s): Lucchesi; Nicholas D
• Assistant Examiner(s): Stigell; Theodore J
• Application Number:
  US10/641,507
• Publication Number:
  US 20040121486A1
• Time in Patent Office: 2,055 Days
• Field of Search: 604/890.1, 604/891.1, 604/892.1, 604 20- 21, 604 65- 67, 604 82- 92, 604/244, 604/246, 604/256, 604285-288, 604/69, 604/93.01, 60428801-28804, 436174-175
• US Class Current: 604/890.1
• 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 substrate having at least one reservoir;

a discrete reservoir cap in register with the at least one reservoir and 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 and directly contacting said reservoir cap; and

an electrical output lead connected to and directly contacting 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 and the substrate is not ruptured.

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 the substrate.

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

19. The device of claim 18, wherein the therapeutic or prophylactic agent comprises a parathyroid hormone.

20. The device of claim 19, wherein the parathyroid hormone comprises a human parathyroid hormone.

21. The device of claim 18, wherein the reservoir contents comprises human parathyroid hormone hPTH(1-34).

22. The device of claim 1, which is a subeomponent of an implantable drug delivery device.

23. The device of claim 22, 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.

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

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

26. The device of claim 1, wherein the reservoir contents comprises human parathyroid hormone hPTH(1-34).

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

a substrate;

a plurality of discrete reservoirs provided in the substrate;

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

a plurality of discrete reservoir caps, each 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 and directly contacting each of said reservoir caps, 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 each of the reservoir caps and not the substrate.

28. The device of claim 27, comprising four or more reservoirs positioned in a two-dimensional array in the substrate.

29. The device of claim 28, 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.

30. The device of claim 27, 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.

31. The device of claim 27, wherein the reservoir contents comprises a release system comprising drug molecules.

32. The device of claim 31, wherein the drug molecules comprise a parathyroid hormone.

33. The device of claim 32, wherein the parathyroid hormone comprises a human parathyroid hormone.

34. The device of claim 27, further comprising activation means for controlling said application of electric current through each reservoir cap.

35. The device of claim 34, wherein said activation means comprises a microprocessor or state machine.

36. The device of claim 34, wherein said activation means comprises an active electronic component effective to eliminate unintended reservoir opening.

37. The device of claim 36, wherein the active electronic component comprises a diode or transistor.

38. The device of claim 27, wherein the substrate is in a shape selected from the group consisting of disks, cylinders, or spheres.

39. The device of claim 27, wherein a dielectric material is interposed between the reservoir cap and the substrate to thennally isolate the reservoir cap from the substrate.

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

a discrete 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 and directly contacting 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,

wherein (i) the reservoir cap and the input and output leads are designed to provide upon the application of electrical current an increase in electrical current density in the reservoir cap relative to the current density in the input and output leads, (ii) the material forming the reservoir cap has a different electrical resistivity, thermal diffusivity, thermal conductivity, and/or a lower melting temperature than the material forming the input and output leads, or (iii) the reservoir cap and the input and output leads are designed to provide upon the application of electrical current an increase in electrical current density in the reservoir cap relative to the current density in the input and output leads, and the material forming the reservoir cap has a different electrical resistivity, thermal diffusivity, thermal conductivity, and/or a lower melting temperature than the material forming the input and output leads.

41. The device of claim 40, further comprising at least one reservoir for containing the drug, said reservoir being at least partially enclosed by the reservoir cap.

42. The device of claim 41, comprising a plurality of reservoirs and a plurality of reservoir caps.

43. The device of claim 40, wherein the drug comprises a parathyroid hormone.

44. The device of claim 40, wherein the parathyroid hormone comprises a human parathyroid hormone.

45. The device of claim 44, wherein the reservoir contents comprises human parathyroid hormone hPTH(1-34).

46. A medical device for the controlled exposure of a sensor comprising:

a substrate;

a plurality of reservoirs provided in the substrate;

a plurality of sensors located in said plurality of reservoirs;

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

a pair of conductive leads electrically connected to and directly contacting 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 and not the substrate.

47. The device of claim 46, wherein the sensors detect a physiological condition in a patient.

48. The device of claim 47, wherein the sensor is a biosensor.

49. The device of claim 48, wherein the biosensor measures the concentration of glucose, urea, calcium, or a hormone in the patient.

50. 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 and directly contacting said reservoir cap; and

an electrical output lead connected to and directly contacting 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,

wherein (i) the reservoir cap and the input and output leads are designed to provide upon the application of electrical current an increase in electrical current density in the reservoir cap relative to the current density in the input and output leads, (ii) the material forming the reservoir cap has a different electrical resistivity, thermal diffusivity, thermal conductivity, and/or a lower melting temperature than the material forming the input and output leads, or (iii) the reservoir cap and the input and output leads are designed to provide upon the application of electrical current an increase in electrical current density in the reservoir cap relative to the current density in the input and output leads, and the material forming the reservoir cap has a different electrical resistivity, thermal diffusivity, thermal conductivity, and/or a lower melting temperature than the material forming the input and output leads.