Isolating lead conductor for fault detection

• US 9,539,428 B2
• Filed: 01/27/2011
• Issued: 01/10/2017
• Est. Priority Date: 01/27/2011
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Germanson, Nancy M., Spear, Thomas H., Miller, Patrick David
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): Patel, Natasha
• Application Number:
  US13/014,965
• Publication Number:
  US 20120197331A1
• Time in Patent Office: 2,175 Days
• Field of Search: 607/37, 607/38, 607/148
• US Class Current: 1/1
• CPC Class Codes: A61N 1/3706 Pacemaker parameters stimulation threshold A61N1/371
• CPC Class Codes: A61N 1/3925 Monitoring; Protecting
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72

Abstract

Systems and methods for providing a cardiac stimulus device lead having fault tolerance and fault isolation are disclosed. A medical electrical lead is provided according to one aspect. According to one embodiment, the lead includes a first conductor and a second conductor for transmitting an electrical pulse from a pulse generator. The lead further includes a switching mechanism, a first electrode, and a lead assessment circuit. The switching mechanism selectively couples the first conductor to the first electrode. The first electrode is decoupled during a test phase and the switching mechanism directly couples the first conductor to the second conductor. The lead assessment circuit processes a signal associated with the electrical properties of the lead to determine whether the lead is exhibiting a lead related condition.

Claims

1. A medical electrical lead-electrode system, comprising:

a stimulus therapy generator;

an electrode for interfacing with tissue of a patient;

a first conductor having a first distal end connected to the tissue interface electrode and a first proximal end connected to the stimulus therapy generator;

a second conductor having a second proximal end connected to the stimulus therapy generator;

means for isolating the first distal end of said first conductor from the tissue interface electrode and for coupling said first distal end to the second distal end of said second conductor, wherein the stimulus therapy generator generates a signal for transmission through the first and second conductor; and

a signal processor for receiving the signal propagated through the first and second conductors.

2. The medical electrical lead-electrode system of claim 1, further comprising control means for controlling the isolating and coupling means.

3. The medical electrical lead-electrode system of claim 1, wherein the isolating means disconnects the tissue interface electrode from the first conductor to directly connect the first distal end to the second distal end.

4. The medical electrical lead-electrode system of claim 3, wherein the isolating means disconnects the tissue interface electrode from the first conductor in response to generation of the test signal.

5. The medical electrical lead-electrode system of claim 4, wherein the test signal is generated at a predetermined period following issuance of a pacing pulse.

6. The medical electrical lead-electrode system of claim 4, wherein the test signal is generated during a blanking period following a ventricular event.

7. The medical electrical lead-electrode system of claim 4, wherein the test signal is generated during a blanking period following an atrial event.

8. The medical electrical lead-electrode system of claim 1, wherein the signal processor includes:

a differential amplifier configured to receive a signal from the first conductor and the second conductor; and

a comparator configured to compare the output of the differential amplifier with a programmable threshold voltage.

9. The medical electrical lead-electrode system of claim 1, wherein the isolating means comprises a switch.

10. The medical electrical lead-electrode system of claim 1, wherein the isolating means comprises a multiplexer.

11. A method of detecting a fault in a medical electrical lead, comprising:

providing a first conductor and a second conductor;

providing a first electrode;

providing a first switch;

selectively actuating the first switch to couple the first electrode to a first distal end of the first conductor; and

providing a controller communicatively coupled to the first switch for transmitting a control signal, wherein in response to receiving the control signal, the first switch decouples the first electrode from the first conductor and directly couples the first conductor to the second conductor.

12. The method of claim 11, further comprising providing a diagnostic unit configured to receive and process a signal from the first and second conductor to detect a fault in the first and second conductors.

13. The method of claim 11, wherein the controller is configured to transmit the control signal during a blanking period of a cardiac therapy delivery cycle.

14. The method of claim 11, wherein the controller is configured to transmit the control signal at a predetermined period following issuance of a pacing pulse.

15. The method of claim 11, further comprising:

providing a second electrode;

providing a second switch communicatively coupled to the controller; and

selectively actuating the second switch to couple the second electrode to a second distal end of the second conductor, wherein in response to receiving the control signal, the second switch decouples the first electrode from the second conductor.