Implantable medical device having flat electrolytic capacitor with consolidated electrode tabs and corresponding feedthroughs

• US 6,141,205 A
• Filed: 06/24/1998
• Issued: 10/31/2000
• Est. Priority Date: 04/03/1998
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Johnson, William L., Lessar, Joseph F., Rorvick, Anthony W., Breyen, Mark D., Casby, Kurt J., Nutzman, Thomas M., Miltich, Thomas P.
• Primary Examiner(s): Kincaid, Kristine
• Assistant Examiner(s): Thomas, Eric W.
• Application Number:
  US09/103,876
• Time in Patent Office: 860 Days
• Field of Search: 361/301.3, 361/301.4, 361/302, 361/303, 361/504, 361/508, 361/511-512, 361/516, 361/517, 361/520, 361/523, 361/522, 361/524, 361/528, 361/530-532, 361/535 , 361/537, 361/538, 361/541, 607/5
• US Class Current: 361/509
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion

Abstract

An implantable medical device such as a defibrillator is described. The device includes an hermetically sealed housing containing a flat electrolytic capacitor and an energy source such as a battery. The battery is connected to the capacitor and provides charge thereto. The capacitor stores the charge at a relatively high voltage. The charge stored in the capacitor is discharged through a defibrillation lead to a site on or in the heart when fibrillation of the heart is detected by the implantable medical device. Methods of making and using the implantable medical device, the capacitor, and their various components are disclosed.

Claims

1. A substantially flat electrolytic capacitor suitable for use in an hermetically sealed implantable medical device, comprising:

(a) at least one flat cathode layer being formed of cathode foil and having a first perimeter of a first overall length, the cathode layer having top and bottom surfaces and at least a first tab projecting from the first perimeter at a first predetermined perimeter location, the first tab having a first width;

(b) a plurality of flat anode layers formed of anode foil, the plurality of anode layers forming an anode sub-assembly having top and bottom surfaces, at least two of the plurality of anode layers each being a first anode layer having a second perimeter of a second overall length and at least a second tab projecting from the second perimeter at a second predetermined perimeter location, the second tab having a second width;

(c) at least a first separator layer formed of separator material, the first separator layer defining a third perimeter having a third physical dimension;

(d) a first cathode feedthrough means comprising a first coiled basal portion having a first inside diameter for receiving the first width therewithin and a cathode feedthrough pin extending from the first coiled basal portion;

(e) a first anode feedthrough means comprising a second coiled basal portion having a second inside diameter for receiving at least two of the second tabs and an anode feedthrough pin extending from the second coiled basal portion;

(f) a case having sidewalls extending upwardly from a flat planar base to form an open end;

(g) a cover for sealing the open end of the case;

wherein the at least one cathode layer, the plurality of anode layers and the first separator layer are vertically stacked in the case to form an electrode assembly such that the first separator layer is disposed between the at least one cathode layer and the anode sub-assembly, the first tab is aligned with a first predetermined registration position in the electrode assembly, and the at least two second tabs are aligned with a second predetermined registration position in the electrode assembly, the first coiled basal portion receiving the first width of the first tab therewithin and being connected thereto, the second coiled basal portion receiving the second width of each of the at least two second tabs therewithin and being connected thereto, the cover being sealingly disposed over the open end of the case.

2. The capacitor of claim 1, further comprising a second cathode layer formed of cathode foil and having a fourth perimeter, and a second separator layer formed of separator material, the second cathode layer having at least a third tab having a third width projecting from the third perimeter at a third predetermined perimeter location, the second cathode layer and the second separator layer being included within the electrode assembly such that the second separator layer is disposed between the anode sub-assembly and the second cathode layer, the first tab and the third tab being vertically aligned such that the first predetermined registration location of the electrode assembly coincides vertically with the third predetermined registration location of the electrode assembly, the first coiled basal portion receiving the first width of the first tab and the third width of the third tab therewithin and being connected thereto.

3. The capacitor of claim 1, further comprising a second separator layer formed of separator material and a second anode sub-assembly comprising a plurality of anode layers formed of anode foil, at least one of the plurality of anode layers of the second anode sub-assembly being a fourth anode layer having a fourth perimeter, at least a fourth tab having a fourth width projecting from the fourth perimeter at a fourth predetermined perimeter location, vertically stacking the second anode sub-assembly and the second separator layer in the stacked electrode assembly such that the second separator layer is disposed between the at least one cathode layer and the second anode sub-assembly, and vertically aligning the second tab and the fourth tab such that the second predetermined registration location of the electrode assembly coincides vertically with the fourth predetermined registration location of the electrode assembly, the second coiled basal portion receiving the second width of each of the at least two second tabs and the fourth width of the fourth tab therewithin and being connected thereto.

4. The capacitor of claim 1, wherein the first cathode feedthrough means is a proximal end of the cathode feedthrough pin, the proximal end of the cathode feedthrough pin being coiled around the first tab.

5. The capacitor of claim 1, wherein the first anode feedthrough means is a proximal end of the anode feedthrough pin, the proximal end of the anode feedthrough pin being coiled around the at least two of the second tabs.

6. The capacitor of claim 1, wherein the first cathode feedthrough means is selected from the group consisting of a crimp, a cold weld, a laser weld, an ultrasonic weld and a resistance weld.

7. The capacitor of claim 1, wherein the first anode feedthrough means is selected from the group consisting of a crimp, a cold weld, a laser weld, an ultrasonic weld and a resistance weld.

8. The capacitor of claim 1, wherein the first cathode feedthrough means further comprises an intermediate strain relief component disposed between the proximal end of the first cathode feedthrough means and the cathode feedthrough pin.

9. The capacitor of claim 1, wherein the first anode feedthrough means further comprises an intermediate strain relief component disposed between the proximal end of the first anode feedthrough means and the anode feedthrough pin.

10. The capacitor of claim 1, wherein the cathode layer is formed from aluminum cathode foil.

11. The capacitor of claim 1, wherein the anode layers are formed of through-etched aluminum anode foil.

12. The capacitor of claim 1, wherein each anode layer has a specific capacitance selected from the group consisting of at least about 0.3 microfarads/cm², at least about 0.5 microfarads/cm², and at least about 0.8 microfarads/cm².

13. The capacitor of claim 1, wherein each anode layer has a thickness selected from the group consisting of from about 20 micrometers to about 300 micrometers, from about 40 micrometers to about 200 micrometers, from about 60 micrometers to about 150 micrometers, and from about 70 micrometers to about 140 micrometers.

14. The capacitor of claim 1, wherein the cathode layer is formed from a highly etched cathode foil.

15. The capacitor of claim 1, wherein the cathode layer is formed from aluminum cathode foil having a specific capacitance selected from the group consisting of at least about 100 microfarads/cm², at least about 200 microfarads/cm², at least about 250 microfarads/cm², and at least about 300 microfarads/cm².

16. The capacitor of claim 1, wherein the cathode layer is formed from aluminum foil having a thickness selected from the group consisting of from about 10 micrometers to about 200 micrometers, from about 15 micrometers to about 150 micrometers, from about 20 micrometers to about 100 micrometers, from about 25 micrometers to about 75 micrometers, and about 30 micrometers.

17. The capacitor of claim 1, wherein the anode sub-assembly comprises a plurality of non-notched anode layers and at least one notched anode layer.

18. The capacitor of claim 1, wherein the anode layers in the anode sub-assembly are cold welded together.

19. The capacitor of claim 1, wherein the at least first separator layer is pressure bonded to the anode sub-assembly.

20. The capacitor of claim 1, wherein the top and bottom surfaces of the anode sub-assembly are covered by the first separator layer and a second separator layer.

21. The capacitor of claim 1, wherein the first separator layer has a perimeter extending beyond the perimeter of the anode sub-assembly.

22. The capacitor of claim 1, wherein the implantable medical device is selected from the group consisting of a PCD, an AID, an ICD, a defibrillator, an implantable pulse generator and a pacemaker.

23. The capacitor of claim 1, wherein the plurality of anode layers is connected electrically to the case.

24. The capacitor of claim 1, wherein the at least one cathode layer is electrically connected to the case.

25. The capacitor of claim 1, wherein the case is connected electrically to neither the at least one cathode layer nor to the plurality of anode layers.

26. The capacitor of claim 1, wherein the electrode assembly is secured by means for securing the electrode assembly.

27. The capacitor of claim 26, wherein the means for securing the electrode assembly comprises an electrode wrap and corresponding adhesive strip.

28. The capacitor of claim 1, wherein at least portions of the first separator layer are secured at the periphery thereof to corresponding portions of a second separator layer by at least one of crimping, stitching, adhesive bonding, ultrasonic paper welding and direct pressure bonding.

29. The capacitor of claim 1, wherein the case is formed of aluminum or aluminum alloy.

30. The capacitor of claim 1, wherein the at least one cathode layer has no holes for registration disposed therethrough.

31. The capacitor of claim 1, wherein the plurality of flat anode layers have no holes for registration disposed therethrough.

32. A substantially flat electrolytic capacitor suitable for use in an hermetically sealed implantable medical device, comprising:

(a) at least one flat cathode layer being formed of cathode foil and having a first perimeter of a first overall length, the cathode layer having top and bottom surfaces and at least a first tab projecting from the first perimeter at a first predetermined perimeter location, the first tab having a first width;

(b) at least two anode sub-assemblies, each of said anode sub-assemblies comprising a plurality of flat anode layers formed of anode foil, each of the plurality of anode layers having top and bottom surfaces, at least one of the plurality of anode layers of each anode sub-assembly being a first anode layer having a second perimeter of a second overall length and at least a second tab projecting from the second perimeter at a second predetermined perimeter location;

(c) at least two separator layers formed of separator material, each of the separator layers defining a third perimeter having a third physical dimension;

(d) a first cathode feedthrough means comprising a first coiled basal portion having a first inside diameter for receiving the first width therewithin and a cathode feedthrough pin extending from the first coiled basal portion; and

(e) a first anode feedthrough means comprising a second coiled basal portion having a second inside diameter for receiving the second tabs of the at least two anode sub-assemblies therewithin and an anode feedthrough pin extending from the second coiled basal portion;

wherein the at least one cathode layer, the plurality of anode layers and the first separator layer are vertically stacked in the case to form an electrode assembly such that a first one of the at least two separator layers is disposed between the at least one cathode layer and one of the at least two anode sub-assemblies, the first tab is aligned with a first predetermined registration position in the electrode assembly, a second one of the at least two separator layers is disposed between the first one and a second one of the at least two anode sub-assemblies, the second tabs of first and second ones of the at least two anode sub-assemblies are aligned with a second predetermined registration position in the electrode assembly, the first coiled basal portion receiving the first width of the first tab therewithin and being connected thereto, the second coiled basal portion receiving the second width of the second tabs of the first and the second of the at least two anode sub-assemblies and being connected thereto.

33. The capacitor of claim 32, further comprising a second cathode layer formed of cathode foil and having a fourth perimeter, and a third separator layer formed of separator material, the second cathode layer having at least a third tab having a third width projecting from the third perimeter at a third predetermined perimeter location, the second cathode layer and the third separator layer being included within the electrode assembly such that the second separator layer is disposed between the anode sub-assembly and the second cathode layer, the first tab and the third tab being vertically aligned such that the first predetermined registration location of the electrode assembly coincides vertically with the third predetermined registration location of the electrode assembly, the first coiled basal portion receiving the first width of the first tab and the third width of the third tab therewithin and being connected thereto.

34. A substantially flat electrolytic capacitor suitable for use in an hermetically sealed implantable medical device, comprising:

(a) at least one flat cathode layer being formed of cathode foil and having a first perimeter of a first overall length, the cathode layer having top and bottom surfaces and at least a first tab projecting from the first perimeter at a first predetermined perimeter location, the first tab having a first width;

(b) a plurality of flat anode layers formed of anode foil, the plurality of anode layers forming an anode sub-assembly having top and bottom surfaces, at least one of the plurality of anode layers being a first anode layer having a second perimeter of a second overall length and at least a second tab projecting from the second perimeter at a second predetermined perimeter location, the second tab having a second width;

(c) at least a first separator layer formed of separator material, the first separator layer defining a third perimeter having a third physical dimension;

(d) a first cathode feedthrough means comprising a first coiled basal portion having a first inside diameter for receiving the first width therewithin, a cathode feedthrough pin extending from the first coiled basal portion, and an intermediate strain relief component disposed between a proximal end of the first cathode feedthrough means and the cathode feedthrough pin; and

(e) a first anode feedthrough means comprising a second coiled basal portion having a second inside diameter for receiving the second width therewithin and an anode feedthrough pin extending from the second coiled basal portion;

(f) a case having sidewalls extending upwardly from a flat planar base to form an open end;

(g) a cover for sealing the open end of the case;

wherein the at least one cathode layer, the plurality of anode layers and the first separator layer are vertically stacked in the case to form an electrode assembly such that the first separator layer is disposed between the at least one cathode layer and the anode sub-assembly, the first tab is aligned with a first predetermined registration position in the electrode assembly, and the second tab is aligned with a second predetermined registration position in the electrode assembly, the first coiled basal portion receiving the first width of the first tab therewithin and being connected thereto, the second coiled basal portion receiving the second width of the second tab therewithin and being connected thereto, the cover being sealingly disposed over the open end of the case.

35. A substantially flat electrolytic capacitor suitable for use in an hermetically sealed implantable medical device, comprising:

(a) at least one flat cathode layer being formed of cathode foil and having a first perimeter of a first overall length, the cathode layer having top and bottom surfaces and at least a first tab projecting from the first perimeter at a first predetermined perimeter location, the first tab having a first width;

(b) a plurality of flat anode layers formed of anode foil, the plurality of anode layers forming an anode sub-assembly having top and bottom surfaces, at least one of the plurality of anode layers being a first anode layer having a second perimeter of a second overall length and at least a second tab projecting from the second perimeter at a second predetermined perimeter location, the second tab having a second width;

(c) at least a first separator layer formed of separator material, the first separator layer defining a third perimeter having a third physical dimension;

(d) a first cathode feedthrough means comprising a first coiled basal portion having a first inside diameter for receiving the first width therewithin and a cathode feedthrough pin extending from the first coiled basal portion;

(e) a first anode feedthrough means comprising a second coiled basal portion having a second inside diameter for receiving the second width therewithin, an anode feedthrough pin extending from the second coiled basal portion, and an intermediate strain relief component disposed between a proximal end of the first anode feedthrough means and the anode feedthrough pin; and

(f) a case having sidewalls extending upwardly from a flat planar base to form an open end;

(g) a cover for sealing the open end of the case;

wherein the at least one cathode layer, the plurality of anode layers and the first separator layer are vertically stacked in the case to form an electrode assembly such that the first separator layer is disposed between the at least one cathode layer and the anode sub-assembly, the first tab is aligned with a first predetermined registration position in the electrode assembly, and the second tab is aligned with a second predetermined registration position in the electrode assembly, the first coiled basal portion receiving the first width of the first tab therewithin and being connected thereto, the second coiled basal portion receiving the second width of the second tab therewithin and being connected thereto, the cover being sealingly disposed over the open end of the case.

36. A substantially flat electrolytic capacitor suitable for use in an hermetically sealed implantable medical device, comprising:

(a) at least one flat cathode layer being formed of cathode foil and having a first perimeter of a first overall length, the cathode layer having top and bottom surfaces and at least a first tab projecting from the first perimeter at a first predetermined perimeter location, the first tab having a first width;

(b) a plurality of flat anode layers formed of anode foil, at least one of the anode layers being a notched anode layer and more than one of the anode layers being non-notched anode layers, the plurality of anode layers forming an anode sub-assembly having top and bottom surfaces, at least one of the plurality of anode layers being a first anode layer having a second perimeter of a second overall length and at least a second tab projecting from the second perimeter at a second predetermined perimeter location, the second tab having a second width;

(c) at least a first separator layer formed of separator material, the first separator layer defining a third perimeter having a third physical dimension;

(d) a first cathode feedthrough means comprising a first coiled basal portion having a first inside diameter for receiving the first width therewithin and a cathode feedthrough pin extending from the first coiled basal portion;

(e) a first anode feedthrough means comprising a second coiled basal portion having a second inside diameter for receiving the second width therewithin and an anode feedthrough pin extending from the second coiled basal portion; and

(f) a case having sidewalls extending upwardly from a flat planar base to form an open end;

(g) a cover for sealing the open end of the case;

wherein the at least one cathode layer, the plurality of anode layers and the first separator layer are vertically stacked in the case to form an electrode assembly such that the first separator layer is disposed between the at least one cathode layer and the anode sub-assembly, the first tab is aligned with a first predetermined registration position in the electrode assembly, and the second tab is aligned with a second predetermined registration position in the electrode assembly, the first coiled basal portion receiving the first width of the first tab therewithin and being connected thereto, the second coiled basal portion receiving the second width of the second tab therewithin and being connected thereto, the cover being sealingly disposed over the open end of the case.

37. A substantially flat electrolytic capacitor suitable for use in an hermetically sealed implantable medical device, comprising:

(a) at least one flat cathode layer being formed of cathode foil and having a first perimeter of a first overall length, the cathode layer having top and bottom surfaces and at least a first tab projecting from the first perimeter at a first predetermined perimeter location, the first tab having a first width;

(b) a plurality of flat anode layers formed of anode foil, the plurality of anode layers forming an anode sub-assembly having top and bottom surfaces, at least onc of the plurality of anode layers being a first anode layer having a second perimeter of a second overall length and at least a second tab projecting from the second perimeter at a second predetermined perimeter location, the second tab having a second width;

(c) at least a first separator layer formed of separator material, the first separator layer defining a third perimeter having a third physical dimension;

(d) a first cathode feedthrough means comprising a first coiled basal portion having a first inside diameter for receiving the first width therewithin and a cathode feedthrough pin extending from the first coiled basal portion;

(e) a first anode feedthrough means comprising a second coiled basal portion having a second inside diameter for receiving the second width therewithin and an anode feedthrough pin extending from the second coiled basal portion;

(f) a case having sidewalls extending upwardly from a flat planar base to form an open end;

(g) a cover for sealing the open end of the case; and

(h) means for securing the at least one cathode layer, the plurality of anode layers and the first separator layer to prevent movement or shifting, the means for securing comprising an electrode wrap and corresponding adhesive strip;

wherein the at least one cathode layer, the plurality of anode layers and the first separator layer are vertically stacked in the case to form an electrode assembly such that the first separator layer is disposed between the at least one cathode layer and the anode sub-assembly, the first tab is aligned with a first predetermined registration position in the electrode assembly, and the second tab is aligned with a second predetermined registration position in the electrode assembly, the first coiled basal portion receiving the first width of the first tab therewithin and being connected thereto, the second coiled basal portion receiving the second width of the second tab therewithin and being connected thereto, and the cover being sealingly disposed over the open end of the case.

38. A substantially flat electrolytic capacitor suitable for use in an hermetically sealed implantable medical device, comprising:

(a) at least one flat cathode layer being formed of cathode foil and having a first perimeter of a first overall length, the cathode layer having top and bottom surfaces and at least a first tab projecting from the first perimeter at a first predetermined perimeter location, the first tab having a first width;

(b) a plurality of flat anode layers formed of anode foil, the plurality of anode layers forming an anode sub-assembly having top and bottom surfaces, at least one of the plurality of anode layers being a first anode layer having a second perimeter of a second overall length and at least a second tab projecting from the second perimeter at a second predetermined perimeter location, the second tab having a second width;

(c) at least a first separator layer formed of separator material, the first separator layer defining a third perimeter having a third physical dimension;

(d) a first cathode feedthrough means comprising a first coiled basal portion having a first inside diameter for receiving the first width therewithin and a cathode feedthrough pin extending from the first coiled basal portion;

(e) a first anode feedthrough means comprising a second coiled basal portion having a second inside diameter for receiving the second width therewithin and an anode feedthrough pin extending from the second coiled basal portion; and

(f) a case having sidewalls extending upwardly from a flat planar base to form an open end;

(g) a cover for sealing the open end of the case;

wherein the at least one cathode layer, the plurality of anode layers and the first separator layer are vertically stacked in the case to form an electrode assembly such that the first separator layer is disposed between the at least one cathode layer and the anode sub-assembly, the first tab is aligned with a first predetermined registration position in the electrode assembly, wherein at least portions of the first separator layer are secured at the periphery thereof to corresponding portions of a second separator layer by at least one of crimping, stitching, adhesive bonding, ultrasonic paper welding and direct pressure bonding, and the second tab is aligned with a second predetermined registration position in the electrode assembly, the first coiled basal portion receiving the first width of the first tab therewithin and being connected thereto, the second coiled basal portion receiving the second width of the second tab therewithin and being connected thereto, the cover being sealingly disposed over the open end of the case.