EMI shielded conduit assembly for an active implantable medical device

• US 8,095,224 B2
• Filed: 03/17/2010
• Issued: 01/10/2012
• Est. Priority Date: 03/19/2009
• Status: Expired due to Fees

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Inventors: Truex, Buehl E., Stevenson, Robert A., Brendel, Richard L.
• Primary Examiner(s): Layno, Carl H.
• Assistant Examiner(s): MORALES, JON ERIC C
• Application Number:
  US12/725,903
• Publication Number:
  US 20100241206A1
• Time in Patent Office: 664 Days
• Field of Search: 600/12, 600/439, 600/420, 607/9, 607/116
• US Class Current: 607/116
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61B 2562/182 Electrical shielding, e.g. using a Faraday cage
• CPC Class Codes: A61B 2562/222 Electrical cables or leads therefor, e.g. coaxial cables or ribbon cables
• CPC Class Codes: A61B 2562/227 Sensors with electrical connectors
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61N 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: G01R 33/285 Invasive instruments, e.g. catheters or biopsy needles, specially adapted for tracking, guiding or visualization by NMR

Abstract

An EMI shielded conduit assembly for an active implantable medical device (AIMD) includes an EMI shielded housing for the AIMD, a hermetic feedthrough terminal associated with the AIMD housing, and an electronic circuit board, substrate or network disposed within the AIMD housing remote from the hermetic feedthrough terminal. At least one leadwire extends from the hermetic feedthrough terminal to the remote circuit board, substrate or network. An EMI shield is conductively coupled to the AIMD housing and substantially co-extends about the leadwire in non-conductive relation thereto.

Claims

1. An EMI shielded conduit assembly for an active implantable medical device (AIMD), comprising:

a) an AIMD comprising a housing;

a hermetic feedthrough terminal comprising a ferrule supporting an insulative material sealing between at least one conductive leadwire and an inner surface of the ferrule, wherein the ferrule is hermetically sealed and electrically connected to the AIMD housing;

c) an electronic circuit board or substrate disposed within the AIMD housing remote from the hermetic feedthrough terminal;

d) at least one capacitor mounted on the circuit board or substrate and comprising spaced apart first and second electrode plates encased in a dielectric material, wherein the at least one leadwire extends from the feedthrough terminal to a proximal end of the leadwire electrically connected to the first electrode plates of the capacitor mounted on the circuit board or substrate; and

e) an EMI shield comprising a substantially continuous covering that is in a non-conductive relationship around an outer perimeter of the at least one leadwire, but that conductively extends along the length thereof from a distal shield end electrically connected to the ferrule to a proximal shield end electrically connected to the second electrode plates of the capacitor mounted on the remote electronic circuit board or substrate.

2. The EMI shielded conduit assembly of claim 1, wherein the electronic circuit board or substrate comprises a low pass EMI filter, an L-C trap, a bandstop filter, or a combination thereof.

3. The EMI shielded conduit assembly of claim 2, wherein the low pass EMI filter and the L-C trap are grounded to the EMI shield.

4. The EMI shielded conduit assembly of claim 2 or 3, wherein the low pass EMI filter comprises a capacitor.

5. The EMI shielded conduit assembly of claim 4, wherein the low pass EMI filter comprises a feedthrough capacitor, an MLCC chip capacitor, a flat-through capacitor, an X2Y attenuator, or a multi-element low-pass filter, or a combination thereof.

6. The EMI shielded conduit assembly of claim 2 or 3, wherein the low pass EMI filter comprises an active electronic filter.

7. The EMI shielded conduit assembly of claim 1 or 2, including a high voltage suppression network associated with the remote electronic circuit board or substrate.

8. The EMI shielded conduit assembly of claim 7, wherein the high voltage suppression network is grounded to the EMI shield.

9. The EMI shielded conduit assembly of claim 7, wherein the high voltage suppression network comprises a diode array.

10. The EMI shielded conduit assembly of claim 1, wherein the electronic circuit board or substrate comprises a programmable short-to-housing switch network.

11. The EMI shielded conduit assembly of claim 1, wherein the AIMD housing comprises a conductive equipotential surface.

12. The EMI shielded conduit assembly of claim 11, wherein the AIMD housing comprises a metallic can.

13. The EMI shielded conduit assembly of claim 2 or 3, wherein the low pass filter, the L-C trap, or the bandstop filter is disposed on the circuit board or the substrate.

14. The EMI shielded conduit assembly of claim 13, wherein the EMI shield extends from the hermetic feedthrough terminal to the low pass EMI filter, the L-C trap, or the bandstop filter.

15. The EMI shielded conduit assembly of claim 1, wherein the at least one leadwire comprises a plurality of leadwires, and the EMI shield comprises at least two EMI shields conductively coupled to the AIMD housing and each substantially co-extending about at least one respective leadwire in non-conductive relation.

16. The EMI shielded conduit assembly of claim 15, including a non-conductive insulator disposed between each leadwire and its respective EMI shield.

17. The EMI shielded conduit assembly of claim 1 or 16, wherein the EMI shield comprises a conductive heat-shrink tubing.

18. The EMI shielded conduit assembly of claim 1, wherein the EMI shield comprises a conductive foil, wire, braid, mesh, circuit trace, or solid tubular material.

19. The EMI shielded conduit assembly of claim 9, wherein the EMI shield is radially spaced from the at least one leadwire.

20. The EMI shielded conduit assembly of claim 18, including a flex cable embodying the at least one leadwire and the EMI shield.

21. The EMI shielded conduit assembly of claim 1 wherein the leadwire includes at least one inductor intermediate the housing and the capacitor.

22. An EMI shielded conduit assembly for an active implantable medical device (AIMD), comprising:

a) an AIMD comprising a housing;

b) a hermetic feedthrough terminal comprising an insulative material sealing between at least one conductive leadwire and an inner surface of an opening in the housing;

c) an electronic circuit board or substrate disposed within the AIMD housing remote from the hermetic feedthrough terminal;

d) at least one capacitor mounted on the circuit board or substrate and comprising spaced apart first and second electrode plates encased in a dielectric material, wherein the at least one leadwire extends from the housing to a proximal end of the leadwire electrically connected to the first electrode plates of the capacitor mounted on the circuit board or substrate; and

e) an EMI shield comprising a substantially continuous covering that is in a non-conductive relationship around an outer perimeter of the at least one leadwire, but that conductively extends along the length thereof from a distal shield end electrically connected to the housing to a proximal shield end electrically connected to the second electrode plates of the capacitor mounted on the remote electronic circuit board or substrate.