LEAD INTEGRITY TESTING TRIGGERED BY SENSED SIGNAL SATURATION

• US 20100023084A1
• Filed: 07/28/2008
• Published: 01/28/2010
• Est. Priority Date: 07/28/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gunderson, Bruce D.
• Granted Patent: US 9,522,277 B2
• Time in Patent Office: Days
• US Class Current: 607/28
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/3706 Pacemaker parameters stimulation threshold A61N1/371

Abstract

Techniques for performing a lead integrity test in response to, e.g., during or after saturation of a sensed signal, e.g., a cardiac electrogram (EGM) signal, are described. A lead integrity test may comprise one or more impedance measurements for one or more leads. Possible causes of saturation of a sensed signal include lead conductor or connector issues, or other lead related conditions. A lead integrity test triggered in response to the saturation may be able to detect any lead related condition causing the saturation. A lead integrity test triggered in response to the saturation may advantageously be able to detect an intermittent lead related condition, due to the temporal proximity of the test to the saturation.

Claims

1. A method comprising:

sensing a physiological signal of a patient via one or more electrodes on at least one implantable medical lead;

detecting saturation of the signal; and

triggering a lead integrity test of the implantable medical lead in response to the detection.

2. The method of claim 1, wherein the signal comprises a cardiac electrogram signal.

3. The method of claim 1, wherein triggering a lead integrity test comprises measuring an impedance for each of one or more electrical paths that include the electrodes on the at least one implantable lead.

4. The method of claim 1, wherein detecting saturation of the signal comprises

digitizing the signal;

and

comparing an amplitude of the digitized signal to a threshold.

5. The method of claim 1, further comprising determining whether the signal is saturated for at least one of a threshold duration or a threshold number of samples, wherein triggering a lead integrity test comprises triggering the lead integrity test in response to the determination.

6. The method of claim 1, wherein detecting saturation of the signal comprises detecting saturation with an amplifier that provides an indication when the signal is at least about equal to a threshold.

7. The method of claim 1, wherein detecting saturation of the signal comprises:

detecting clamping of the signal; and

detecting saturation of the signal based on the clamping.

8. The method of claim 1, further comprising performing the lead integrity test during the saturation of the signal.

9. The method of claim 1, wherein detecting saturation and triggering a lead integrity test comprises detecting saturation and triggering the lead integrity test with an implantable medical device coupled to the at least one implantable medical lead.

10. The method of claim 1, further comprising at least one of storing the sensed signal when saturated or providing an alert in response to detecting the saturation.

11. A system comprising:

an implantable medical lead comprising one or more electrodes;

an implantable medical device (IMD) coupled to the lead that senses a physiological signal of a patient via the electrodes; and

a processor that;

detects saturation of the signal; and

controls the IMD to perform a lead impedance measurement of the implantable medical lead in response to the detection.

12. The system of claim 11, wherein the signal comprises a cardiac electrogram.

13. The system of claim 11, wherein the IMD comprises an impedance measurement module, and the processor controls the impedance measurement module to measure an impedance of each of one or more electrical paths that include the electrodes on the at least one implantable medical lead in response to the detection.

14. The system of claim 11, further comprising an analog-to-digital converter that digitizes the signal, wherein the processor compares an amplitude of the digitized signal to a threshold to detect saturation of the signal.

15. The system of claim 11, wherein the processor determines whether the signal is saturated for at least one of a threshold duration or a threshold number of samples, and controls the IMD to perform the lead integrity test in response to the determination.

16. The system of claim 11, wherein the IMD comprises an amplifier that indicates when the signal is at least about equal to the threshold, and the processor detects saturation of the signal based on the indication.

17. The system of claim 11,

wherein the IMD comprises a clamp circuit that clamps the signal and provides an indication when the signal is clamped, and

wherein the processor detects saturation of the signal based on the indication.

18. The system of claim 11, wherein the processor controls the IMD to perform the integrity test during the saturation of the signal.

19. The system of claim 11, further comprising an external programmer that presents an alert to a user based on the integrity test.

20. The system of claim 11, wherein the processor changes at least one of a sensing configuration or a therapy configuration based on the integrity test.

21. The system of claim 11, wherein the processor comprises a processor of the IMD.

22. The system of claim 11, wherein the IMD comprises at least one of a pacemaker, cardioverter, or defibrillator.

23. The system of claim 11, further comprising a memory, wherein the processor at least one of stores the sensed signal when saturated in the memory or activates an alert in response to detecting the saturation.

24. A computer-readable medium comprising instructions that cause a processor to:

detect saturation of a physiological signal of a patient sensed via one or more electrodes on at least one implantable medical lead; and

trigger a lead integrity test of the implantable medical lead in response to the detection.

25. A system comprising:

means for sensing a physiological signal of a patient via one or more electrodes on at least one implantable medical lead;

means for detecting saturation of the signal; and

means for triggering a lead integrity test of the implantable medical lead in response to the detection.