Implantable medical device assembly and manufacturing method

• US 20030040779A1
• Filed: 08/21/2001
• Published: 02/27/2003
• Est. Priority Date: 08/21/2001
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Tidemand, Kevin K., Patras, George, Engmark, David B., Olson, Robert L., Bruchmann, Richard A., Ceballos, Thomas, Schaefer, Todd
• Granted Patent: US 6,721,602 B2
• Time in Patent Office: Days
• US Class Current: 607/36
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/3754 Feedthroughs

Abstract

In general, the invention is directed to an implantable medical device assembly having a more space-efficient housing and components, as well as processes for assembling the implantable medical device with reduced assembly cost and less complexity. The implantable medical device may incorporate a battery, capacitor, circuit assembly, feedthrough assembly, and interconnect assembly with respective electrical terminals. This configuration permits the use of automated electronic module assembly techniques such as parallel gap or ribbon bond welding to electrically connect the terminals. A feedthrough assembly may present a set of terminals adjacent a corresponding set of circuit terminals, also enabling the use of automated welding techniques.

Claims

1. An implantable medical device comprising:

a housing;

a battery within the housing and having battery terminals;

a capacitor within the housing and having capacitor terminals; and

a circuit assembly within the housing and having circuit terminals,

wherein the battery terminals and the capacitor terminals form a first row of terminals, the circuit terminals form a second row of terminals adjacent the first row of terminals, and the circuit terminals are electrically coupled to the battery terminals and the capacitor terminals.

2. The device of claim 1, wherein the battery is positioned side-by-side with a lower portion of the capacitor, and the circuit assembly is positioned over the battery and side-by-side with an upper portion of the capacitor, the battery and circuit assembly having a combined thickness that approximates a thickness of the capacitor.

3. The device of claim 2, wherein the circuit assembly and the capacitor present a generally planar surface, the device further comprising an interconnect assembly mounted over the generally planar surface.

4. The device of claim 3, wherein the first and second rows of terminals are substantially linear and extend substantially parallel to one another, the interconnect assembly includes conductive ribbons oriented to bridge adjacent terminals in the first and second rows of terminals, and the circuit terminals are electrically coupled to the battery terminals and the capacitor terminals via welded bonds formed by the conductive ribbons.

5. The device of claim 1, wherein the first and second rows of terminals are substantially linear and extend substantially parallel to one another, and the circuit terminals are electrically coupled to the battery terminals and the capacitor terminals via parallel gap welded bonds or ribbon welded bonds.

6. The device of claim 1, wherein the capacitor includes a terminal block assembly that extends outward from the capacitor and positions the capacitor terminals adjacent the battery terminals along a lateral surface of the battery in substantial alignment with the first row of terminals.

7. The device of claim 1, wherein the first row of terminals is positioned along a lateral surface of the battery, and the second row of terminals is positioned along an edge of the circuit assembly.

8. The device of claim 1, further comprising an interconnect assembly positioned within the housing, wherein the interconnect assembly includes a first set of interconnect terminals positioned adjacent and electrically coupled to at least some of the circuit terminals, a second set of interconnect terminals positioned remotely from the circuit terminals, and conductors that electrically couple the first and second sets of interconnect terminals.

9. The device of claim 8, wherein the interconnect terminals include conductive ribbons oriented to contact at least some of the circuit terminals.

10. The device of claim 8, further comprising a feedthrough assembly positioned within the housing and having feedthrough terminals positioned adjacent and electrically coupled to additional terminals that electrically couple at least some of the feedthrough terminals to at least some of the circuit terminals.

11. The device of claim 10, further comprising a flex circuit connector that electrically couples the feedthrough terminals to at least some of the circuit terminals.

12. The device of claim 10, further comprising one or more pins that extend from the feedthrough assembly and outward from the housing, wherein the circuit assembly includes a charging circuit that applies current from the battery to charge the capacitor, and a pulse generation circuit that applies current from the capacitor to deliver electrical pulses to the pins via the feedthrough terminals for cardiac stimulation.

13. The device of claim 10, wherein the feedthrough assembly includes an electrically insulative terminal block, multiple contact elements mounted in an interior side of the insulative terminal block to form the feedthrough terminals, and first channels formed in an exterior side of the insulative terminal block for communication of the conductive pins to the contact elements.

14. The device of claim 13, wherein the contact elements define second channels in communication with the first channels, the pins being threaded through the first and second channels and fixed in place to electrically couple the pins to the contact elements.

15. The device of claim 14, wherein proximal ends of the pins are welded to the contact elements.

16. The device of claim 13, wherein the feedthrough assembly includes first and second feedthrough assemblies, each of the first and second feedthrough assemblies accommodating at least two of the conductive pins.

17. The device of claim 8, wherein the first set of interconnect terminals form a third row of terminals substantially parallel to the first and second rows of terminals, the first set of interconnect terminals being electrically coupled to at least some of the circuit terminals via parallel gap welded bonds or ribbon welded bonds.

18. The device of claim 17, wherein the interconnect assembly includes an antenna for radio frequency telemetry and an audible alarm device electrically coupled to at least some of the circuit terminals via the first set of interconnect terminals.

19. The device of claim 8, wherein the battery and the capacitor are positioned side-by-side, the circuit assembly is positioned over the battery, and the interconnect assembly is positioned over the circuit assembly and the capacitor.

20. A method for assembling an implantable medical device, the method comprising:

positioning a battery having battery terminals within a housing;

positioning a capacitor having capacitor terminals within the housing such that the capacitor terminals form a first row of terminals with the battery terminals;

positioning a circuit assembly having circuit terminals within the housing, wherein the circuit terminals form a second row of terminals and the circuit assembly is positioned such that second row of terminals is positioned adjacent the first row of terminals; and

electrically coupling the battery terminals and the capacitor terminals to the circuit terminals using an automated process.

21. The method of claim 20, further comprising positioning the battery side-by-side with a lower portion of the capacitor, and positioning the circuit assembly over the battery and side-by-side with an upper portion of the capacitor, the battery and circuit assembly having a combined thickness that approximates a thickness of the capacitor.

22. The method of claim 21, wherein the circuit assembly and the capacitor present a generally planar surface, the method further comprising mounting an interconnect assembly over the generally planar surface.

23. The method of claim 22, wherein the first and second rows of terminals are substantially linear and extend substantially parallel to one another, the interconnect assembly includes conductive ribbons oriented to bridge adjacent terminals in the first and second rows of terminals, and the method further comprises electrically coupling the circuit terminals to the battery terminals and the capacitor terminals via welded bonds formed by the conductive ribbons.

24. The method of claim 20, wherein the first and second rows of terminals are substantially linear and extend substantially parallel to one another, the method further comprising electrically coupling the circuit terminals to the battery terminals and the capacitor terminals via parallel gap welded bonds or ribbon welded bonds.

25. The method of claim 24, wherein the first row of terminals is positioned along a lateral surface of the battery, and the second row of terminals is positioned along an edge of the circuit assembly.

26. The method of claim 24, further comprising:

positioning an interconnect assembly having interconnect terminals within the housing such that a first set of interconnect terminals are positioned adjacent the circuit terminals and a second set of interconnect terminals are positioned remotely from the circuit terminals, the interconnect assembly including conductors that electrically couple the first and second sets of interconnect terminals; and

electrically coupling at least some of the interconnect terminals to at least some of the circuit terminals using an automated welding process.

27. The method of claim 26, further comprising:

positioning a feedthrough assembly having feedthrough terminals within the housing such that the feedthrough terminals are positioned adjacent the second set of interconnect terminals; and

electrically coupling at least some of the feedthrough terminals to at least some of the circuit terminals using an automated welding process.

28. The method of claim 27, further comprising:

positioning a flex circuit connector between the circuit terminals and the feedthrough terminals; and

electrically coupling the feedthrough terminals to at least some of the circuit terminals via the flex circuit connector.

29. The method of claim 26, further comprising electrically coupling one or more conductive pins to the feedthrough terminals, wherein the pins extend from the feedthrough assembly and away from the housing.

30. The method of claim 26, wherein the feedthrough assembly includes an electrically insulative terminal block, multiple contact elements mounted within an interior side of the insulative terminal block to form the feedthrough terminals, and first channels formed in an exterior side of the terminal block for communication of conductive pins to the contact elements, and wherein the contact elements define second channels in communication with the first channels, the method further comprising threading the pins through the first and second channels and fixing the pins in place to electrically couple the pins to the contact elements.

31. The method of claim 30, wherein fixing the pins in place includes welding the pins to the contact elements using an automated welding process.

32. The method of claim 30, further comprising welding the pins to the contact elements.

33. The method of claim 30, wherein the feedthrough assembly includes first and second feedthrough assemblies, each of the first and second feedthrough assemblies accommodating at least two of the conductive pins.

34. The method of claim 30, further comprising press-fitting the contact elements into the insulative terminal block.

35. The method of claim 26, wherein the interconnect assembly includes an antenna for radio frequency telemetry and an audible alarm device electrically coupled to the circuit terminals via the first set of interconnect terminals.

36. The method of claim 26, further comprising:

positioning the battery and the capacitor side-by-side;

positioning the circuit assembly over the battery; and

positioning the interconnect assembly over the circuit assembly and the capacitor.

37. A feedthrough assembly for an implantable medical device, the feedthrough assembly comprising:

an electrically insulative terminal block;

multiple contact elements mounted in an interior side of the insulative terminal block to form feedthrough terminals;

first channels formed in an exterior side of the insulative terminal block for communication of conductive pins to the contact elements;

second channels formed in the contact elements for receipt of the conductive pins; and

multiple conductive pins threaded through the first and second channels and fixed in place to electrically couple the pins to the contact elements.

38. The feedthrough assembly of claim 37, wherein the pins are welded to the contact elements.

39. The feedthrough assembly of claim 37, wherein the feedthrough assembly includes first and second feedthrough sub-assemblies, each of the first and second feedthrough assemblies accommodating at least two of the conductive pins.

40. The feedthrough assembly of claim 37, wherein the contact elements are press-fit into recesses in the interior side of the insulative terminal block.

41. The feedthrough assembly of claim 37, further comprising a discoidal capacitor positioned about the pins to filter electromagnetic interference from electrical signals carried by the pins.

42. The feedthrough assembly of claim 37, further comprising a hermetically sealed ferrule that supports the pins, the ferrule being fixed to the insulative terminal block.

43. A capacitor assembly for an implantable medical device, the capacitor assembly comprising:

a housing;

a capacitor positioned within the housing;

capacitor terminals coupled to respective electrodes of the capacitor; and

a terminal block assembly that carries the capacitor terminals and extends outward from the housing and positions the capacitor terminals for placement adjacent and in substantial linear alignment with battery terminals associated with a battery assembly.

44. The capacitor assembly of claim 43, wherein the housing is sized and shaped for placement within an implantable cardiac stimulation device.

45. The capacitor assembly of claim 43, wherein the capacitor terminals are welded to feedthrough wires that extend from the capacitor electrodes.

46. A battery assembly for an implantable medical device, the battery assembly comprising:

a housing;

a battery positioned within the housing;

battery terminals coupled to respective electrodes of the battery; and

a terminal block assembly that carries the battery terminals and extends outward from the housing and positions the battery terminals for placement adjacent and in substantial linear alignment with capacitor terminals associated with a capacitor assembly.

47. The battery assembly of claim 46, wherein the housing is sized and shaped for placement within an implantable cardiac stimulation device.

48. The capacitor assembly of claim 46, wherein at least some of the battery terminals are welded to an exterior surface of the battery assembly.