Conditioning of coupled electromagnetic signals on a lead

• US 20030144721A1
• Filed: 04/30/2002
• Published: 07/31/2003
• Est. Priority Date: 01/29/2002
• Status: Active Grant

• Current Assignee: Metronic Incorporated
• Original Assignee: Metronic Incorporated
• Inventors: Haubrich, Gregory J., Dublin, Garry L., Villaseca, Eduardo H.
• Granted Patent: US 7,013,180 B2
• Time in Patent Office: Days
• US Class Current: 607/122
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• 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: Y10S 128/901 Suppression of noise in electric signal

Abstract

A method and an apparatus for reducing coupled electrical energy resulting from an electromagnetic field. Embodiments of the present invention provide for an elongate body having a proximal end portion, a middle portion, and a distal end portion and at least one coil wound about at least one of the proximal end portion, the middle portion, and the distal end portion, the coil to provide for filtering of radio frequency (RF) signal-coupled electrical energy.

Claims

1. A medical electrical lead, comprising:

an elongate body having a proximal end portion, a middle portion, and a distal end portion and at least one coil wound about at least one of said proximal end portion, said middle portion, and said distal end portion, said coil positioned to provide for filtering of radio frequency (RF) signal-coupled electrical energy at least at one of said proximal end portion and said distal end portion.

2. The medical electrical lead of claim 1, wherein said coil includes a filter for filtering RF signal-coupled electrical energy resulting from the presence of a magnetic resonance imaging (MRI) signal.

3. The medical electrical lead of claim 1, wherein said coil includes a filter for filtering RF signal-coupled electrical energy resulting from the presence of a radio diathermy signal.

4. The medical electrical lead of claim 1, wherein said coil includes an electromagnetic trap for filtering radio frequency (RF) signal-coupled electrical energy.

5. The medical electrical lead of claim 4, wherein said electromagnetic trap is a filter.

6. The medical electrical lead of claim 1, further comprising a first coil and a second coil being wound about said medical electrical lead, said first coil being wound more loosely than said second coil such that said second coil provides at least one of a different inductance compared to an inductance provided by said first coil, and a different parallel parasitic capacitance compared to a parasitic capacitance provided by said first coil.

7. The medical electrical lead of claim 1, further comprising a capacitor operatively coupled to a substantially terminus region of said medical electrical lead.

8. The medical electrical lead of claim 7, further comprising a coil being wound about said capacitor.

9. The medical electrical lead of claim 8, wherein said coil includes a winding about said capacitor and provides a equivalent circuit comprising a capacitor in parallel with an inductance, said equivalent circuit to reduce said radio frequency (RF) signal-coupled electrical energy.

10. The medical electrical lead of claim 1, wherein said coil comprises:

a conductive wire; and

an electrically insulative layer surrounding said conductive wire.

11. The medical electrical lead of claim 10, wherein said medical electrical lead includes an equivalent resistance resulting from a resistance of said coil and a wire.

12. The medical electrical lead of claim 11, wherein said coil includes a connection in series with said equivalent resistance to provide an inductive impedance.

13. The medical electrical lead of claim 12, wherein said inductive impedance is functional during the presence of a radio frequency signal.

14. The medical electrical lead of claim 13, wherein said inductive impedance is functional during the presence of a electromagnetic field resulting from at least one of a 27 MHz signal, 64 MHz signal, and a 128 MHz signal.

15. The medical electrical lead of claim 12, wherein said coil includes a connection in parallel with said inductive impedance to provide a capacitive impedance, wherein said inductive impedance includes a connection in series with said equivalent resistance and said capacitive impedance includes a parallel circuit in series with a resistive value.

16. The medical electrical lead of claim 15, wherein said capacitive impedance is a lumped element.

17. The medical electrical lead of claim 15, wherein said capacitive impedance is functional during the presence of a radio frequency signal.

18. The medical electrical lead of claim 17, wherein said capacitive impedance is functional during the presence of a electromagnetic field resulting from at least one of a 27 MHz signal, a 64 MHz signal, and a 128 MHz signal.

19. The medical electrical lead of claim 15, wherein said inductive and capacitive impedance to provide a self-resonant circuitry during the presence of an RF signal.

20. A medical electrical lead, comprising:

an elongate body having a proximal end portion, a middle portion, and a distal end portion and at least one coil wound about at least one of said proximal end portion, said middle portion, and said distal end portion, said coil to provide an inductive impedance in parallel with a capacitive impedance for reducing coupled electrical energy at least on said proximal end portion and said distal end portion, resulting in the presence of an electromagnetic field.

21. The medical electrical lead of claim 20, wherein said inductive and said capacitive impedance are active during the presence of a electromagnetic field resulting from at least one of a 27 MHz signal, 64 MHz signal, and a 128 MHz signal.

22. The medical electrical lead of claim 20, wherein said coil comprises:

a conductive wire; and

an electrically insulative layer surrounding said conductive wire.

23. The medical electrical lead of claim 20, wherein said inductive and capacitive impedances are structured to provide a self-resonant circuitry during the presence of an RF signal.

24. A implantable medical device system, comprising:

an implantable medical device; and

a medical electrical lead operatively coupled to said implantable medical device, said medical electrical lead having a proximal end portion, a middle portion, and a distal end portion and at least one coil wound about at least one of said proximal end portion, said middle portion, and said distal end portion, said coil to provide an inductive impedance in parallel with a capacitive impedance for reducing coupled electrical energy resulting in the presence of an electromagnetic field.

25. The implantable medical device system of claim 24, wherein said implantable medical device comprises a connector block wherein said proximate end portion of said medical electrical lead is positioned within said connector module, said proximate end portion having a coil wound about.

26. The implantable medical device system of claim 24, wherein said inductive impedance and said capacitive impedance form a filter to pass a sensor signal and to block said coupled electrical energy.

27. The implantable medical device system of claim 24, wherein said inductive impedance and said capacitive impedance form a filter to pass a pacing signal and to block said coupled electrical energy.

28. The implantable medical device system of claim 24, wherein said inductive and capacitive impedance provide a self-resonant circuitry during the presence of an said electromagnetic signal, and said self-resonant circuitry blocks an coupled electrical energy resulting from an RF signal within a pre-determined range of frequency.

29. A method for trapping an radio frequency (RF) signal coupled to electrical energy on a medical electrical lead, comprising:

providing at least one wound coil around at least one of a proximate end portion, a middle portion, and a distal end portion of said medical electrical lead such that said coil provides an inductive impedance in parallel with a capacitive impedance to reduce said coupled electrical energy.

30. The method of claim 29, wherein winding said coil around said medical electrical lead further includes winding said coil such that a self resonating circuit comprising an inductive impedance and a capacitive impedance is active in the presence of said RF signal.

31. The method of claim 30, wherein winding said coil around said medical electrical lead further includes a wound structure of said coil such that said self resonating circuit is active in the presence of at least one of a 27 MHz signal, a 64 MHz signal, and a 128 MHz signal.