Cardiac pacing/sensing lead providing far-field signal rejection

• US 7,305,270 B1
• Filed: 04/21/2005
• Issued: 12/04/2007
• Est. Priority Date: 04/21/2005
• Status: Expired due to Fees

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Kroll, Mark W., Helland, John R.
• Primary Examiner(s): Mullen; Kristen D.
• Assistant Examiner(s): WU, TONG E
• Application Number:
  US11/112,508
• Time in Patent Office: 957 Days
• Field of Search: 607/9, 607/115, 607/116, 607/119, 607/122, 607/123, 607126-132, 600/372, 600/374, 600/375, 600/393, 600/509, 600/521
• US Class Current: 607/127
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/0573 chacterised by means penetrating the heart tissue, e.g. helix needle or hook
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/3704 Circuits specially adapted therefor, e.g. for sensitivity control

Abstract

A proximal end of a lead body carries a connector assembly. A first electrical conductor within the lead body electrically connects a tip electrode to a first electrical contact on the connector assembly. A collar electrode is carried by a distal end portion of the lead body. A second electrical conductor within the lead body electrically connects the collar electrode to a second electrical contact on the connector assembly. A ring electrode, carried by the distal end portion of the lead body, is disposed proximally of the collar electrode in spaced-apart relationship thereto and is connected through a switching device to a node point along the first conductor. The switching device has a first state permitting an electrical current to be conducted between the ring electrode and the node point and a second state in which the ring electrode is electrically isolated from the node point. Preferably, the switching device comprises a diode.

Claims

1. A cardiac lead for transmitting electrical pacing and sensing signals between an electrical medical device and selected cardiac tissue, the lead comprising:

a lead body having a proximal end, a distal tip and a distal end portion extending proximally from the distal tip, the proximal end of the lead body carrying a connector assembly electrically connectable to the electrical medical device;

a first pacing/sensing electrode at the distal tip of the lead body;

a first electrical conductor within the lead body electrically connecting the first pacing/sensing electrode to a first electrical contact on the connector assembly;

a second pacing/sensing electrode carried by the distal end portion of the lead body at the distal tip thereof;

a second electrical conductor within the lead body electrically connecting the second electrode to a second electrical contact on the connector assembly; and

a third pacing/sensing electrode carried by the distal end portion of the lead body, the third electrode being disposed proximally of the second pacing/sensing electrode in spaced-apart relationship thereto, a switching device connecting the third pacing/sensing electrode to a node point along the first electrical conductor to electrically separate a pacing dipole from a sensing dipole;

wherein during pacing, the switching device has a first state permitting an electrical current to be conducted between the third pacing/sensing electrode and the node point when the first electrical conductor is pulsed with a sufficient voltage pulse amplitude to pulse both the first pacing/sensing electrode and the third pacing/sensing electrode such that the third pacing/sensing electrode is a backup electrode in a dipole comprising the second pacing/sensing electrode and the third pacing/sensing electrode when the first pacing/sensing electrode develops too high a pacing threshold; and

wherein during sensing, the switching device has a second state in which the third pacing/sensing electrode is electrically isolated from the node point when voltage generated by the heart is insufficient to switch the switching device from a non-conducting state to a conducting state such that sensing is performed between the first pacing/sensing electrode and the third pacing/sensing electrode.

2. The lead of claim 1 in which:

the switching device comprises a diode.

3. The lead of claim 2 in which:

the diode comprises a cathode electrically connected to the node point and an anode electrically connected to the third pacing/sensing electrode, the node point being disposed along the first conductor.

4. The lead of claim 1 in which:

the lead body carries a shocking electrode positioned proximally of the third pacing/sensing electrode, the shocking electrode being adapted to be electrically connected to a separate contact on the connector assembly.

5. The lead of claim 1 in which:

the first pacing/sensing electrode and the second pacing/sensing electrode comprise a sensing dipole.

6. The lead of claim 1 in which:

the first pacing/sensing electrode and the second pacing/sensing electrode comprise a pacing dipole.

7. The lead of claim 1 in which:

the second pacing/sensing electrode and the third pacing/sensing electrode comprise a pacing dipole.

8. A cardiac lead for transmitting electrical pacing and sensing signals between an electrical medical device and selected cardiac tissue, the lead comprising:

a lead body having a proximal end, a distal tip and a distal end portion extending proximally from the distal tip, the proximal end of the lead body carrying a connector assembly electrically connectable to the electrical medical device;

a helical screw-in pacing/sensing electrode extendable and retractable relative to the distal tip of the lead body;

a first electrical conductor within the lead body electrically connecting the helical screw-in pacing/sensing electrode to a first electrical contact on the connector assembly;

a collar pacing/sensing electrode carried by the distal end portion of the lead body at the distal tip thereof;

a second electrical conductor within the lead body electrically connecting the collar pacing/sensing electrode to a second electrical contact on the connector assembly; and

a ring pacing/sensing electrode carried by the distal end portion of the lead body, the ring pacing/sensing electrode being disposed proximally of the collar pacing/sensing electrode in spaced-apart relationship thereto, the ring pacing/sensing electrode being connected through a switching device to a node point along the first electrical conductor to electrically separate a pacing dipole from a sensing dipole;

wherein during pacing, the switching device has a first state permitting an electrical current to be conducted between the ring pacing/sensing electrode and the node point when the first electrical conductor is pulsed with a sufficient voltage pulse amplitude to pulse both the helical screw-in pacing/sensing electrode and the ring pacing/sensing electrode such that the ring pacing/sensing electrode is a backup electrode in a dipole comprising the collar pacing/sensing electrode and the ring pacing/sensing electrode when the helical screw-in pacing/sensing electrode develops too high a pacing threshold; and

wherein during sensing, the switching device has a second state in which the ring pacing/sensing electrode is electrically isolated from the node point when voltage generated by the heart is insufficient to switch the switching device from a non-conducting state to a conducting state such that sensing is performed between the helical screw-in pacing/sensing electrode and the collar pacing/sensing electrode.

9. The lead of claim 8 in which:

the helical screw-in pacing/sensing electrode and the collar pacing/sensing electrode comprise a sensing dipole.

10. The lead of claim 8 in which:

the helical screw-in pacing/sensing electrode and the collar pacing/sensing electrode comprise a pacing dipole.

11. The lead of claim 8 in which:

the collar pacing/sensing electrode and the ring pacing/sensing electrode comprise a pacing dipole.

12. The lead of claim 8 in which:

the switching device comprises a diode and the diode remains nonconducting when a voltage generated by the heart is less than a forward voltage drop of the diode.

13. The lead of claim 8 in which:

the interelectrode spacing between a distal extremity of the ring pacing/sensing electrode and a proximal extremity of the collar pacing/sensing electrode ranges from 5 to 30 mm.