Medical device for sensing glucose

• US 20050096587A1
• Filed: 11/03/2004
• Published: 05/05/2005
• Est. Priority Date: 11/03/2003
• Status: Active Grant

• Current Assignee: DARE MB Incorporated
• Original Assignee: MicroCHIPS Inc.
• Inventors: Santini, John T. Jr., Herman, Stephen J.
• Granted Patent: US 8,095,197 B2
• Time in Patent Office: Days
• US Class Current: 604/66
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing

Abstract

Medical devices, utilizing multiple reservoirs to protect and selectively expose sensors or other reservoir contents, are provided having (i) a reservoir contents destruction mechanism to interrupt the release or exposure of reservoir contents, for example, to deactivate an unneeded sensor and prevent it from negatively impacting other sensors, (ii) a protective covering material layer over the sensor underneath the reservoir cap, which protects the sensor membrane and sensor during reservoir cap disintegration and then is removed, (iii) a device design for containing sensors in shallow, wide reservoir structures to enhance sensor exposure by minimizing molecular diffusion distances, (iv) an implantable sensor unit and a separate drug delivery unit, or (v) combinations thereof.

Claims

1. A device for the controlled exposure of a secondary device, comprising:

a substrate;

a plurality of reservoirs in the substrate;

an operational secondary device in one or more of the reservoirs;

a reservoir cap covering each of the reservoirs to isolate the secondary device from an environmental component outside the reservoirs, wherein the reservoir cap is impermeable to the environmental component;

means for disintegrating or permeabilizing the reservoir cap to expose the secondary device to the environmental component; and

means for selectively rendering the secondary device inoperable.

2. The device of claim 1, wherein the means for disintegrating or permeabilizing comprises a microprocessor programmed to initiate said disintegrating or permeabilizing at a specified time, upon receipt of a signal from another device, or upon detection of a specified sensed condition.

3. The device of claim 1, wherein the secondary device comprises a sensor or a sensing component.

4. The device of claim 3, wherein the sensor or sensing component comprises a glucose sensor.

5. The device of claim 4, wherein the sensor or sensing component comprises glucose oxidase.

6. The device of claim 1, wherein the means for selectively rendering the secondary device inoperable comprises a thermal ablation electrode, which renders the operational secondary device inoperable upon passage of an electric current therethrough.

7. The device of claim 1, wherein the means for selectively rendering the secondary device inoperable comprises a resistive heater.

8. The device of claim 7, wherein the sensor or sensor component comprises an enzyme and the resistive heater generates heat effective to deactivate the enzyme.

9. The device of claim 8, wherein the enzyme comprises a glucose oxidase.

10. The device of claim 1, wherein the means for selectively rendering the secondary device inoperable comprises one or more chemical reactant materials that react to generate energy, an expanding gas, or other reaction product to render the operational secondary device inoperable.

11. The device of claim 1, wherein the substrate comprises two or more portions bonded together.

12. The device of claim 1, wherein the substrate is monolithic.

13. The device of claim 1, further comprising a biodegradable intermediary material disposed in the reservoir underneath the reservoir cap and covering the secondary device.

14. The device of claim 1, further comprising a thin layer of a structural material underneath the reservoir cap and an evacuated or gas-filled space in the reservoir between the secondary device and the structural material layer.

15. The device of claim 3, wherein the sensor or sensor component comprises at least one working electrode, a counter electrode, an enzyme provided the at least one working electrode, and a semipermeable membrane covering the enzyme and at least part of the at least one working electrode.

16. A medical device, comprising:

an implantable sensor unit which comprises the device of claim 1;

and

a drug delivery unit comprising at least one therapeutic agent for release,

wherein the drug delivery unit is in communication with the implantable sensor unit and releases the therapeutic agent in response to the sensor'"'"'s sensing of the environmental component.

46. A method for detecting or measuring a property at a site, the method comprising the steps of:

providing at the site the device of claim 3;

and

disintegrating or permeabilizing the reservoir cap to expose the sensor or sensing component in one of the reservoirs; and

detecting or measuring a property in or adjacent to the exposed sensor or sensor component.

47. The method of claim 46, further comprising the step of rendering the sensor or sensor component inoperable.

48. The method of claim 47, wherein the sensor or sensor component is rendered inoperable by passing an electric current through a fuse or resistive heater which is positioned proximate the sensor or sensing component.

49. The method of claim 46, wherein the sensor or sensing component is a glucose sensor.

17. A device for the controlled exposure of a secondary device, comprising:

a substrate;

a plurality of reservoirs in the substrate;

a secondary device in one or more of the reservoirs;

a reservoir cap covering each of the reservoirs to isolate the secondary device from an environmental component outside the reservoirs, wherein the reservoir cap is impermeable to the environmental component;

a biodegradable intermediary material disposed in the reservoir underneath the reservoir cap and covering the secondary device; and

means for disintegrating or permeabilizing the reservoir cap to expose the biodegradable intermediary material to a fluid from outside the device to cause the biodegradable intermediary material to disintegrate to expose the secondary device to the environmental component.

18. The device of claim 17, further comprising a layer of a structural material underneath the reservoir cap and disposed between the biodegradable intermediary material and the reservoir cap.

19. The device of claim 18, wherein the structural material comprises a dielectric material.

20. The device of claim 17, wherein the biodegradable intermediary material comprises a water-soluble solid, liquid, or gel.

21. The device of claim 17, wherein the biodegradable intermediary material comprises a polyethylene glycol, a polyethylene oxide, or a copolymer of poly(lactic-co-glycolic) acid.

22. The device of claim 17, wherein the secondary device comprises a sensor or sensor component.

23. The device of claim 22, wherein the sensor or sensing component comprises a glucose sensor.

24. The device of claim 22, wherein the sensor or sensing component comprises glucose oxidase.

25. The device of claim 22, wherein the sensor or sensor component comprises at least one working electrode, a counter electrode, an enzyme provided on the at least one working electrode, and a semipermeable membrane covering the enzyme and at least part of the at least one working electrode.

26. The device of claim 17, further comprising a means for selectively rendering the secondary device inoperable.

27. A medical device comprising:

an implantable sensor unit which comprises the device of claim 17;

and

a drug delivery unit comprising at least one therapeutic agent for release,

wherein the drug delivery unit is in communication with the implantable sensor unit and releases the therapeutic agent in response to the sensor'"'"'s sensing of the environmental component.

36. The device of claim 17, wherein the reservoirs are microreservoirs.

28. A device for the controlled exposure of a secondary device, comprising:

a substrate;

a plurality of reservoirs in the substrate;

a secondary device in one or more of the reservoirs;

a reservoir cap covering each of the reservoirs to isolate the secondary device from an environmental component outside the reservoirs, wherein the reservoir cap is impermeable to the environmental component;

an evacuated or gas-filled space disposed in the reservoir between the reservoir cap and the secondary device; and

means for disintegrating or permeabilizing the reservoir cap to expose the secondary device to the environmental component.

29. The device of claim 28, wherein the space is filled with an inert gas.

30. The device of claim 28, wherein the space is filled with a gas selected from the group consisting of air, nitrogen, helium, and argon.

31. The device of claim 28, wherein the secondary device comprises a sensor or sensor component.

32. The device of claim 31, wherein the sensor or sensing component comprises a glucose sensor.

33. The device of claim 31, wherein the sensor or sensing component comprises glucose oxidase.

34. The device of claim 31, wherein the sensor or sensor component comprises at least one working electrode, a counter electrode, an enzyme provided on the at least one working electrode, and a semipermeable membrane covering the enzyme and at least part of the at least one working electrode.

35. The device of claim 28, further comprising a means for selectively rendering the secondary device inoperable.

37. A medical device comprising:

an implantable sensor unit which comprises the device of claim 28;

and

a drug delivery unit comprising at least one therapeutic agent for release,

wherein the drug delivery unit is in communication with the implantable sensor unit and releases the therapeutic agent in response to the sensor'"'"'s sensing of the environmental component.

38. The device of claim 37, wherein the therapeutic agent comprises insulin.

39. A method of making a device for the controlled exposure of a secondary device comprising the steps of:

providing a substrate having a secondary device which is disposed in a reservoir in the substrate;

depositing a water-soluble material in the reservoir over the secondary device;

depositing a reservoir cap material over the water-soluble material;

contacting the water-soluble material with an aqueous solvent to dissolve the water-soluble material;

removing the water soluble material and solvent from the reservoir through one or more apertures to form an open space in the reservoir in place of the deposited water soluble material; and

plugging the one or more apertures.

40. The method of claim 39, further comprising depositing a layer of a structural material over the water-soluble material before the step of depositing the reservoir cap material.

41. The method of claim 40, further comprising etching one or more apertures through the structural material layer.

42. The method of claim 40, further comprising depositing a reservoir cap material over the structural material layer.

43. The method of claim 40, wherein the structural material comprises a dielectric material.

44. The method of claim 39, wherein the step of plugging the apertures comprises filling the apertures with the reservoir cap material.

45. The method of claim 39, wherein the step of plugging the apertures comprises filling the apertures with a polymeric material.

50. A medical apparatus comprising:

at least one implantable sensor unit which comprises;

a plurality of reservoirs,

a sensor or sensor component provided in the reservoirs,

a reservoir cap covering the reservoirs to isolate the sensor from an environmental component outside the reservoirs, wherein the reservoir cap is impermeable to the environmental component, and

a means for disintegrating or permeabilizing the reservoir cap to expose the sensor to the environmental component; and

at least one drug delivery unit which comprises at least one therapeutic agent for delivery to a patient,

wherein the drug delivery unit is in communication with the implantable sensor unit and releases the therapeutic agent in response to the sensor'"'"'s sensing of the environmental component.

51. The apparatus of claim 50, wherein the drug delivery unit communicates with the sensor unit via at least one flexible conductor connecting the units.

52. The apparatus of claim 50, wherein the flexible conductor includes a connector means for separating and connecting together the units.

53. The apparatus of claim 50, wherein the drug delivery unit is implantable.

54. The apparatus of claim 50, wherein the drug delivery unit is adapted to be worn externally by a patient.

55. The apparatus of claim 50, wherein the drug delivery unit comprises an implantable or external pump for pumping the therapeutic agent into the patient.

56. The apparatus of claim 50, wherein the sensor measures a patient'"'"'s glucose level and the therapeutic agent comprises insulin.

57. The apparatus of claim 50, wherein the drug delivery unit comprises:

a substrate;

a plurality of reservoirs in the substrate;

at least one therapeutic agent in one or more of the reservoirs;

reservoir caps covering the reservoirs to isolate the therapeutic agent inside the reservoirs;

means for disintegrating or permeabilizing one or more of the reservoir caps to release the therapeutic agent from one or more of the reservoirs.

58. The apparatus of claim 50, wherein the communication between the drug delivery unit and the implantable sensor unit comprises transmission of a digital or analog signal.

59. The apparatus of claim 50, wherein the communication between the drug delivery unit and the implantable sensor unit comprises transmission of light, electromagnetic energy, sonic energy, hydraulic energy, or a combination thereof.

60. The apparatus of claim 50, wherein the communication between the drug delivery unit and the implantable sensor unit comprises a conductor.

61. The apparatus of claim 60, wherein the conductor comprises one or more wires, optical fibers, fluid-filled lumens, or combinations thereof.

62. The apparatus of claim 50, wherein the communication between the drug delivery unit and the implantable sensor unit is without a conductor physically connecting the two units.

63. The apparatus of claim 50, further comprising one of more signal encoders/transducers, emitters, receivers, decoders/transducers, or combinations thereof.