Implantable medical device crosstalk evaluation and mitigation

• US 8,611,996 B2
• Filed: 01/30/2009
• Issued: 12/17/2013
• Est. Priority Date: 10/31/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Donofrio, William T., Burnes, John E., Krause, Paul G., Zhou, Xiaohong, Arne, Gerald P., Peichel, David J., Reinke, James D.
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): MAHMOOD, NADIA AHMAD
• Application Number:
  US12/362,842
• Publication Number:
  US 20100114202A1
• Time in Patent Office: 1,782 Days
• Field of Search: 607/18, 607/9, 607/14, 607/6
• US Class Current: 607/4
• CPC Class Codes: A61B 5/304 Switching circuits
• CPC Class Codes: A61B 5/308 for electrocardiography [ECG]
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker
• CPC Class Codes: A61N 1/025 Digital circuitry features of electrotherapy devices, e.g. memory, clocks, processors
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/36185 Selection of the electrode configuration
• CPC Class Codes: A61N 1/3686 configured for selecting the electrode configuration on a lead A61N1/3688 takes precedence
• 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
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• CPC Class Codes: A61N 1/37288 Communication to several implantable medical devices within one patient
• CPC Class Codes: A61N 1/39622 Pacing therapy
• CPC Class Codes: A61N 1/39624 Pain reduction therapy

Abstract

Electrical crosstalk between two implantable medical devices or two different therapy modules of a common implantable medical device may be evaluated, and, in some examples, mitigated. In some examples, one of the implantable medical devices or therapy modules delivers electrical stimulation to a nonmyocardial tissue site or a nonvascular cardiac tissue site, and the other implantable medical device or therapy module delivers cardiac rhythm management therapy to a heart of the patient.

Claims

1. A method of monitoring cardiac activity, the method comprising:

determining, with a processor, whether a therapy module is delivering electrical stimulation to a tissue site within a patient;

selecting, with the processor, a first sense mode or a second sense mode for monitoring cardiac activity of a heart of the patient based on whether the therapy module is delivering electrical stimulation to the tissue site, wherein selecting the first sense mode or the second sense mode comprises;

selecting the first sense mode in response to determining the therapy module is delivering electrical stimulation to the tissue site; and

selecting the second sense mode in response to determining the therapy module is not delivering electrical stimulation to the tissue site;

upon selecting the first sense mode, monitoring, with the processor implementing the first sense mode, cardiac activity of the heart of the patient, wherein monitoring, with the processor implementing the first sense mode, cardiac activity of the patient comprises monitoring electrical cardiac signals of the patient and at least one non-electrophysiological parameter of the patient; and

upon selecting the second sense mode, monitoring, with the processor implementing the second sense mode, cardiac activity of the heart of the patient, wherein monitoring, with the processor implementing the second sense mode, cardiac activity of the patient comprises monitoring electrical cardiac signals of the patient, and wherein the processor monitors at least one different non-electrophysiological parameter of the patient while implementing the first sense mode compared to when the processor is implementing the second sense mode.

2. The method of claim 1, wherein the tissue site comprises at least one of a nonmyocardial tissue site or a nonvascular cardiac tissue site.

3. The method of claim 1, wherein the tissue site comprises at least one of an extravascular tissue site or the tissue site proximate to a nerve of the patient.

4. The method of claim 1, wherein monitoring, with the processor implementing the second sense mode, cardiac activity of the heart of the patient comprises monitoring cardiac activity of the heart of the patient based on fewer non-electrophysiological parameters of the patient compared to the first sense mode.

5. The method of claim 1, wherein the monitoring, with the processor implementing the first sense mode, at least one non-electrophysiological parameter of the patient comprises monitoring at least one of cardiovascular pressure, tissue perfusion, blood oxygen saturation levels, heart sound signals, respiratory rate, intrathoracic impedance, cardiac mechanical activity, muscle movement, ultrasonic signals, heart rate, body temperature, or acoustic signals indicative of cardiac mechanical activity.

6. The method of claim 1, wherein monitoring, with the processor implementing the first sense mode, at least one non-electrophysiological parameter of the patient comprises receiving, from at least one of an external or an implanted sensor, a signal indicative of the at least one non-electrophysiological parameter of the patient indicative of cardiac function.

7. The method of claim 1, wherein the first and second sense modes define different sense vectors with which a sensing module under the control of the processor senses the electrical cardiac signals.

8. The method of claim 7, wherein monitoring, with the processor implementing the first sense mode, electrical cardiac signals comprises controlling the sensing module to sense electrical cardiac signals within a left ventricle of a heart of the patient and outside of a right ventricle of the heart, and wherein monitoring, with the processor implementing the second sense mode, electrical cardiac signals comprises controlling the sensing module to sense electrical cardiac signals within the right ventricle of the heart of the patient and outside of the left ventricle of the heart.

9. The method of claim 7, wherein monitoring, with the processor implementing the first sense mode, electrical cardiac signals comprises controlling a sensing module to sense electrical cardiac signals via at least two electrodes of a lead electrically connected to the sensing module, and wherein monitoring, with the processor implementing the second sense mode, electrical cardiac signals comprises controlling the sensing module to sense electrical cardiac signals via at least one electrode of the lead and an electrode of a housing of a medical device comprising the sensing module.

10. The method of claim 7, monitoring, with the processor implementing the first sense mode, electrical cardiac signals comprises controlling the sensing module to sense electrical cardiac signals via each sensing vector of a plurality of sensing vectors.

11. The method of claim 10, further comprising:

determining a weighted sum of the electrical cardiac signals based on weights applied to the electrical cardiac signals sensed via each sensing vector of the plurality of sensing vectors; and

determining, with the processor, cardiac activity of the patient based on the weighted sum of the electrical cardiac signals sensed via each sensing vector of the plurality of sensing vectors.

12. The method of claim 10, further comprising:

determining a difference between the electrical cardiac signals sensed via each sensing vector of the plurality of sensing vectors; and

determining, with the processor, cardiac activity of the patient based on the difference between the electrical cardiac signals sensed via each sensing vector of the plurality of sensing vectors.

13. The method of claim 1, wherein monitoring, with the processor implementing the first sense mode, cardiac activity of the heart of the patient comprises monitoring electrical cardiac signals of the patient via external electrodes, and wherein monitoring, with the processor implementing the second sense mode, cardiac activity of the heart of the patient comprises monitoring electrical cardiac signals of the patient via implanted electrodes.

14. The method of claim 7, wherein the first sense mode defines a first sense vector comprising a first subset of electrodes electrically connected to the sensing module and the second sense mode defines a second sense vector comprising a second subset of electrodes electrically connected to the sensing module, the first and second subsets of electrodes comprising at least one different electrode.

15. The method of claim 1, further comprising:

detecting, with the processor implementing the first sense mode, a potential arrhythmia of the patient based on the electrical cardiac signals and the at least one non-electrophysiological parameter; and

monitoring, with the processor implementing the second sense mode, electrical cardiac signals in response to detecting the potential arrhythmia.

16. The method of claim 15, wherein the therapy module comprises a first therapy module, the method further comprising:

detecting the potential arrhythmia based on the electrical cardiac signals monitored by the processor while implementing the second sense mode; and

controlling, with the processor, a second therapy module to deliver at least one of a pacing, cardioversion or defibrillation electrical signal to the heart of the patient in response to determining the potential arrhythmia is detected based on the electrical cardiac signals monitored by the processor while implementing the second sense mode.

17. The method of claim 16, wherein the first and second therapy modules are enclosed in a common housing.

18. The method of claim 16, wherein the first therapy module is enclosed in a first housing of a first implantable medical device and the second therapy module is enclosed in a second housing of a second implantable medical device that is physically separate from the first implantable medical device.

19. The method of claim 15, further comprising:

determining, with the processor, whether the potential arrhythmia is detected based on the electrical cardiac signals monitored by the processor while implementing the second sense mode; and

monitoring, with the processor implementing the first mode, electrical cardiac signals and the at least one non-electrophysiological parameter in response to determining the potential arrhythmia is not detected based on the electrical cardiac signals monitored by the processor while implementing the second sense mode.

20. The method of claim 1, wherein the first and second sense modes define at least one of different sensing threshold levels or different amplifier gains with which a sensing module, under the control of the processor, senses electrical cardiac signals.

21. The method of claim 1, wherein the first and second sense modes comprise different filters that are applied to sensed electrical cardiac signals.

22. The method of claim 1, wherein the first and second sense modes comprise different potential arrhythmia event detection algorithms.

23. The method of claim 22, wherein the first sense mode defines an arrhythmia event detection algorithm that detects a potential arrhythmia based on a duration of an S-T segment of an electrical cardiac signal monitored by the processor while implementing the first sense mode.

24. The method of claim 1, wherein determining whether the therapy module is delivering electrical stimulation comprises at least one of receiving an indication from the therapy module or determining the therapy module is delivering stimulation based on known schedule.

47. The method of claim 1, wherein monitoring, with the processor implementing the first sense mode, electrical cardiac signals comprises receiving the electrical cardiac signals from a sensing module, and wherein monitoring, with the processor implementing the second sense mode, electrical cardiac signals comprises receiving the electrical cardiac signals from the sensing module.

48. The method of claim 47, wherein monitoring, with the processor implementing the first sense mode, at least one non-electrophysiological parameter of the patient comprises receiving, from the sensing module, a signal indicative of the at least one non-electrophysiological parameter of the patient, the sensing module comprising a first sensing module configured to sense electrical cardiac signals of the patient and a second sensing module configured to sense the at least one non-electrophysiological parameter of the patient.

49. The method of claim 10, wherein the first sense mode defines a first sensing threshold level that is greater than a second sensing threshold level defined by the second sense mode.

50. The method of claim 10, wherein the first sense mode defines a first amplifier gain that is lower than a second amplifier gain defined by the second sense mode.

51. The method of claim 1, wherein the therapy module comprises a first therapy module, the method further comprising:

detecting, with the processor implementing the first sense mode, a potential arrhythmia of a heart of the patient based on the electrical cardiac signals and the at least one non-electrophysiological parameter;

after detecting the potential arrhythmia, controlling the first therapy module to adjust at least one therapy parameter value of the electrical stimulation delivered to the tissue site;

determining, with the processor, whether the potential arrhythmia is detected after the first therapy module adjusted the at least one therapy parameter value; and

in response to determining the potential arrhythmia is detected after the first therapy module adjusted the at least one therapy parameter value, controlling, with the processor, a second therapy module to deliver at least one of pacing, cardioversion or defibrillation electrical signal to the heart of the patient.

25. A system comprising:

a therapy module configured to deliver electrical stimulation to a tissue site within a patient;

a sensing module; and

a processor configured to determine whether the therapy module is delivering electrical stimulation to the tissue site, and to select a first sense mode or a second sense mode for monitoring cardiac activity of a heart of the patient based on whether the therapy module is delivering electrical stimulation to the tissue site, wherein the processor is configured to select the first sense mode or the second sense mode by at least selecting the first sense mode in response to determining the therapy module is delivering electrical stimulation to the tissue site and selecting the second sense mode in response to determining the therapy module is not delivering electrical stimulation to the tissue site, the processor being further configured to, upon selecting the first sense mode, implement the first sense mode to monitor cardiac activity of the heart of the patient, wherein the processor is configured to, while implementing the first sense mode, control the sensing module to sense electrical cardiac signals and at least one non-electrophysiological parameter of the patient, and the processor being further configured to, upon selecting the second sense mode, implement the second sense mode to monitor cardiac activity of the heart of the patient, wherein the processor is configured to, while implementing the second sense mode, control the sensing module to sense electrical cardiac signals of the patient, and wherein the processor is configured to control the sensing module to sense at least one different non-electrophysiological parameter of the patient while implementing the first sense mode compared to when the processor is implementing the second sense mode.

26. The system of claim 25, wherein the tissue site comprises at least one of a nonmyocardial tissue site or a nonvascular cardiac tissue site.

27. The system of claim 25, wherein the tissue site comprises at least one of an extravascular tissue site or the tissue site proximate to a nerve of the patient.

28. The system of claim 25, wherein the processor, while implementing the second sense mode, is configured to monitor cardiac activity of the heart of the patient by at least controlling the sensing module to sense fewer non-electrophysiological parameters of the patient compared to the first sense mode.

29. The system of claim 25, wherein the at least one non-electrophysiological parameter monitored by the processor while implementing the first sense mode comprises at least one of cardiovascular pressure, tissue perfusion, blood oxygen saturation levels, heart sound signals, respiratory rate, intrathoracic impedance, cardiac mechanical activity, muscle movement, ultrasonic signals, heart rate, body temperature, or acoustic signals indicative of cardiac mechanical activity.

30. The system of claim 25, wherein the sensing module comprises an external portion that is configured to monitor the at least one non-electrophysiological parameter of the patient.

31. The system of claim 25, wherein the first and second sense modes define different sense vectors for sensing the electrical cardiac signals.

32. The system of claim 30, wherein the processor is configured to, while implementing the first sense mode, control the sensing module to sense electrical cardiac signals within a left ventricle of a heart of the patient and outside of a right ventricle of the heart, and wherein the processor is configured to, while implementing the second sense mode, control the sensing module to sense electrical cardiac signals within the right ventricle of the heart of the patient and outside of the left ventricle of the heart.

33. The system of claim 30, further comprising a medical device comprising the sensing module, and a lead electrically connected to the sensing module and comprising a plurality of electrodes, wherein the processor is configured to, while implementing the first sense mode, control the sensing module to sense electrical cardiac signals via at least two electrodes of the plurality of the electrodes of the lead, and, wherein the processor is configured to, while implementing the second sense mode, control the sensing module to sense electrical cardiac signals via at least one electrode of the plurality of electrodes of the lead and an electrode of the housing of the medical device.

34. The system of claim 30, wherein the processor is configured to, while implementing the first sense mode, control the sensing module sense electrical cardiac signals via each sensing vector of a plurality of sensing vectors.

35. The system of claim 30, wherein the processor is configured to, while implementing the first sense mode, control the sensing module to sense electrical cardiac signals via external electrodes, and wherein the processor is configured to, while implementing the second sense mode, control the sensing module to sense electrical cardiac signals via implanted electrodes.

36. The system of claim 30, further comprising a plurality of electrodes coupled to the sensing module, wherein the first sense mode defines a first sense vector comprising a first subset of electrodes of the plurality of electrodes and the second sense mode defines a second sense vector comprising a second subset of electrodes of the plurality of electrodes, the first and second subsets of electrodes comprising at least one different electrode.

37. The system of claim 25, wherein the processor is configured to detect a potential arrhythmia of the patient based on the electrical cardiac signals and the at least one non-electrophysiological parameter sensed by the sensing module while the processor was implementing the first sense mode, and, in response to detecting the potential arrhythmia, implement the second sense mode and control the sensing module to sense the electrical cardiac signals.

38. The system of claim 37, wherein the therapy module comprises a first therapy module, the system further comprising a second therapy module configured to deliver at least one of a pacing, cardioversion or defibrillation electrical signal to a heart of the patient, wherein the processor is configured to detect the potential arrhythmia based on the electrical cardiac signals sensed by the sensing module while the processor was implementing the second sense mode and control the second therapy module to deliver the at least one of a pacing, cardioversion or defibrillation electrical signal to the heart of the patient in response to detecting the potential arrhythmia based on the electrical cardiac signals sensed while the processor was implementing the second sense mode.

39. The system of claim 37, wherein the processor is configured to determine whether the potential arrhythmia is detected based on the electrical cardiac signals sensed by the sensing module while the processor was implementing the second sense mode, and wherein the processor is configured to implement the first sense mode and control the sensing module to sense electrical cardiac signals and the at least one non-electrophysiological parameter in response to determining the arrhythmia is not detected based on the electrical cardiac signals sensed while the processor was implementing the second sense mode.

40. The system of claim 25, wherein the first and second sense modes define at least one of different sensing threshold levels or different amplifier gains with which the sensing module senses the electrical cardiac signals.

41. The system of claim 25, wherein the first and second sense modes comprise different filters that the processor applies to the sensed electrical cardiac signals.

42. The system of claim 25, wherein the first and second sense modes comprise different potential arrhythmia event detection algorithms executed by the processor to detect potential arrhythmia events.

52. The system of claim 25, wherein the sensing module comprises a first sensing module configured to sense electrical cardiac signals of the patient and a second sensing module configured to sense the at least one non-electrophysiological parameter of the patient.

53. The system of claim 40, wherein the first sense mode defines a first sensing threshold level that is greater than a second sensing threshold level defined by the second sense mode.

54. The system of claim 40, wherein the first sense mode defines a first amplifier gain that is lower than a second amplifier gain defined by the second sense mode.

55. The system of claim 25, wherein the therapy module comprises a first therapy module, the system further comprising a second therapy module, wherein the processor is configured to detect, while implementing the first sense mode, a potential arrhythmia of a heart of the patient based on the electrical cardiac signals and the at least one non-electrophysiological parameter, and, after detecting the potential arrhythmia, control the first therapy module to adjust at least one therapy parameter value of the electrical stimulation delivered to the tissue site, determine whether the potential arrhythmia is detected after the first therapy module adjusted the at least one therapy parameter value, and, in response to determining the potential arrhythmia is detected after the first therapy module adjusted the at least one therapy parameter value, control the second therapy module to deliver at least one of pacing, cardioversion or defibrillation electrical signal to the heart of the patient.

43. A system comprising:

means for determining whether a therapy module is delivering electrical stimulation to a tissue site within a patient; and

means for selecting a first sense mode or a second sense mode for monitoring cardiac activity of a heart of the patient based on whether the therapy module is delivering electrical stimulation to the tissue site, wherein the means for selecting selects the first sense mode in response to determining the therapy module is delivering electrical stimulation to the tissue site and selects the second sense mode in response to determining the therapy module is not delivering electrical stimulation to the tissue site;

means for monitoring cardiac activity of a heart of the patient,

wherein, upon selection of the first sense mode by the means for selecting, the means for monitoring cardiac activity implements the first sense mode to monitor cardiac activity of the heart of the patient, wherein the means for monitoring cardiac activity, while implementing the first sense mode, monitors electrical cardiac signals of the patient and at least one non-electrophysiological parameter of the patient, and

wherein, upon selection of the second sense mode by the means for selecting, the means for monitoring cardiac activity of the heart of the patient implements the second sense mode to monitor cardiac activity of the heart of the patient, wherein the means for monitoring cardiac activity, while implementing the second sense mode, monitors electrical cardiac signals of the patient, and wherein the means for monitoring cardiac activity of the patient monitors at least one different non-electrophysiological parameter of the patient while implementing the first sense mode compared to when the second sense mode is implemented.

44. The system of claim 43, wherein when the means for monitoring cardiac activity of the heart of the patient monitors fewer non-electrophysiological parameters of the patient while implementing the second sense mode compared to the first sense mode.

45. The system of claim 43, wherein the means for monitoring cardiac activity, of the heart of the patient while implementing the first sense mode, monitors the at least one non-electrophysiological parameter of the patient by monitoring at least one of cardiovascular pressure, tissue perfusion, blood oxygen saturation levels, heart sound signals, respiratory rate, intrathoracic impedance, cardiac mechanical activity, muscle movement, ultrasonic signals, heart rate, body temperature, or acoustic signals indicative of cardiac mechanical activity.

56. The system of claim 43, wherein the means for monitoring cardiac activity of the heart of the patient comprises means for sensing electrical cardiac signals of the patient and means for sensing the at least one non-electrophysiological parameter of the patient.

57. The system of claim 43, wherein the means for monitoring cardiac activity, while implementing the first sense mode, senses electrical cardiac signals with a first sensing threshold, and, while implementing the second sense mode, senses electrical cardiac signals with a second sensing threshold, the first sensing threshold being greater than the second sensing threshold.

58. The system of claim 43, wherein the means for monitoring cardiac activity, while implementing the first sense mode, applies a first amplifier gain to sensed electrical cardiac signals, and, while implementing the second sense mode, applies a second amplifier gain to sensed electrical cardiac signals, the first amplifier gain being lower than the second amplifier gain.

46. A computer-readable storage medium comprising instructions that cause a programmable processor to:

determine whether a therapy module is delivering electrical stimulation to a tissue site within a patient;

select a first sense mode or a second sense mode for monitoring cardiac activity of a heart of the patient based on whether the therapy module is delivering electrical stimulation to the tissue site, wherein the instructions cause the programmable processor to select the first sense mode or the second sense mode by at least;

selecting the first sense mode in response to determining the therapy module is delivering electrical stimulation to the tissue site; and

selecting the second sense mode in response to determining the therapy module is not delivering electrical stimulation to the tissue site

upon selecting the first sense mode, implement the first sense mode to control a sensing module to monitor cardiac activity of the heart of the patient, wherein the sensing module is configured to sense electrical cardiac signals and at least one non-electrophysiological parameter of the patient in the first sense mode; and

upon selecting the second sense mode, implement the second sense mode to control the sensing module to monitor cardiac activity of the heart of the patient, wherein the sensing module is configured to sense electrical cardiac signals in the second sense mode, wherein the instructions cause the programmable processor to monitor at least one different non-electrophysiological parameter of the patient while implementing the first sense mode compared to programmable processor is implementing the second sense mode.

59. The computer-readable storage medium of claim 46, wherein the instructions cause the processor to, while implementing the first sense mode, control the sensing module to sense electrical cardiac signals using at least one of a different sensing threshold or a different amplifier gain compared to when the processor is implementing the second sense mode.