IMPLANTABLE MEDICAL DEVICE CROSSTALK EVALUATION AND MITIGATION

• US 20100114208A1
• Filed: 01/30/2009
• Published: 05/06/2010
• Est. Priority Date: 10/31/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Davis, Timothy, Krause, Paul G., Donofrio, William T., Zhou, Xiaohong, Reinke, James D., Arne, Gerald P., Peichel, David J., Burnes, John E.
• Granted Patent: US 9,775,987 B2
• Time in Patent Office: Days
• US Class Current: 607/5
• 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 1/3621 for treating or preventing abnormally high heart rate
• CPC Class Codes: A61N 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/37 Monitoring; Protecting
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• CPC Class Codes: A61N 1/37282 characterised by communication with experts in remote locations using a network
• CPC Class Codes: A61N 1/3962 in combination with another heart therapy
• 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 comprising:

determining a characteristic of a first electrical signal sensed by a first implantable medical device (IMD) while a second IMD is delivering a second electrical signal to a tissue site within a patient, wherein the first and second IMDs are implanted within the patient;

comparing the characteristic of the first electrical signal to a threshold value; and

modifying at least one of a stimulation parameter with which the second IMD generates electrical stimulation that is delivered to the tissue site or a sensing parameter with which the first IMD senses the first electrical signal based on the comparison.

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 modifying the at least one of the stimulation parameter or the sensing parameter comprises modifying the at least one of the stimulation parameter or the sensing parameter if the characteristic of the first electrical signal is greater than or equal to the threshold value.

5. The method of claim 1, wherein the first implantable medical device delivers at least one of pacing, cardioversion or defibrillation therapy to a heart of the patient.

6. The method of claim 1, wherein the second implantable medical device delivers at least one of pacing, cardioversion or defibrillation therapy to the tissue site.

7. The method of claim 1, wherein determining the characteristic of the first electrical signal comprises determining a value indicative of a difference between an amplitude of the first electrical signal and a sensing threshold of the first implantable medical device.

8. The method of claim 1, wherein determining the characteristic of the first electrical signal comprises:

suspending delivery of the second electrical signal by the second implantable medical device (IMD);

sensing a third electrical signal with the first IMD;

activating the delivery of the second electrical signal by the second IMD;

sensing the first electrical signal with the first IMD while second IMD delivers the second electrical signal to the tissue site; and

determining a difference between at least one signal characteristic of the first and third electrical signals.

9. The method of claim 8, wherein determining the difference between at least one signal characteristic of the first and third electrical signals comprises:

determining a first value indicative of a difference between a first amplitude of the first electrical signal and a sensing threshold of the first implantable medical device (IMD);

determining a second value indicative of a difference between a second amplitude of the third electrical signal and the sensing threshold of the first IMD; and

determining the difference between the first and second values.

10. The method of claim 9, wherein comparing the characteristic of the first electrical signal to the threshold value comprises determining whether the difference between the first and second values is greater than or equal to the threshold value.

11. The method of claim 10, wherein the threshold value is less than the sensing threshold of the first implantable medical device.

12. The method of claim 11, wherein the threshold value is about 25 percent (%) to about 50% of the sensing threshold of the first implantable medical device.

13. The method of claim 8, wherein determining the difference between at least one signal characteristic of the first and third electrical signals comprises determining the difference between at least one signal characteristic of the first and third electrical signals during a quiet segment of a cardiac cycle of a heart of the patient.

14. The method of claim 8, wherein determining the difference between at least one signal characteristic of the first and third electrical signals comprises determining a difference between one or more frequency band characteristics of the first and third electrical signals.

15. The method of claim 1, wherein determining the characteristic of the first electrical signal comprises determining a first characteristic of the first electrical signal sensed by the first implantable medical device (IMD) at a first time and modifying the at least one of the stimulation parameter or the sensing parameter comprises modifying at least one stimulation parameter, the method further comprising:

delivering a third electrical signal to the tissue site via the second IMD according to the at least one modified stimulation parameter;

determining a second characteristic of a fourth electrical signal sensed by the first IMD at a second time while the second IMD is delivering the third electrical signal; and

determining an electrical noise status based on the second characteristic.

16. The method of claim 15, wherein modifying the stimulation parameter comprises modifying a first value of a first stimulation parameter and determining the electrical noise status based on the second characteristic comprises comparing the second characteristic to the threshold value, the method further comprising, if the second characteristic is greater than or equal to the threshold value, modifying a second value of a second stimulation parameter with which the second implantable medical device generates the electrical stimulation, wherein the first and second stimulation parameters are different.

17. The method of claim 15, wherein determining the electrical noise status based on the second characteristic comprises comparing the second characteristic to the threshold value, the method further comprising modifying the at least one stimulation parameter if the second characteristic is greater than or equal to the threshold value.

18. The method of claim 15, wherein determining the electrical noise status based on the second characteristic comprises comparing the second characteristic to the threshold value, the method further comprising adjusting the delivery of electrical stimulation by the second implantable medical device if the second characteristic is greater than or equal to the threshold value.

19. The method of claim 18, wherein adjusting the delivery of electrical stimulation by the second implantable medical device (IMD) comprises suspending the delivery of electrical stimulation by the second IMD.

20. The method of claim 1, wherein comparing the characteristic of the first electrical signal to the threshold value comprises determining whether the characteristic is greater than or equal to the threshold value, the method further comprising generating and storing an interference indication if the characteristic is greater than or equal to the threshold value.

21. The method of claim 1, wherein the stimulation parameter comprises at least one of a current amplitude, a voltage amplitude, a pulse width, a pulse rate, a frequency, a duty cycle or an electrode combination.

22. The method of claim 1, wherein the sensing parameter comprises at least one of a sensing threshold value, an amplifier gain, a sensing vector, filter characteristic, or a type of physiological parameter of the patient that is sensed by the first implantable medical device.

23. The method of claim 22, wherein the filter characteristic comprises a type of filter applied by the first implantable medical device to the sensed first electrical signal.

24. The method of claim 1, further comprising presenting a waveform indicative of the first electrical signal on a display of a device.

25. The method of claim 1, wherein comparing the characteristic of the first electrical signal to the threshold value comprises determining whether the characteristic is greater than or equal to a first threshold value, the method further comprising:

if the characteristic is greater than or equal to the first threshold value, determining whether the characteristic is greater than or equal to a second threshold value that is different than the first threshold value;

generating a first category indication if the characteristic is not greater than or equal to the second threshold value; and

generating a second category indication if the characteristic is greater than or equal to the second threshold value.

26. The method of claim 1, wherein determining the characteristic of the first electrical signal sensed by the first implantable medical device (IMD) comprises determining the characteristic of the first electrical signal sensed by the first IMD during a quiet segment of a cardiac cycle of a heart of the patient.

27. The method of claim 1, wherein the second electrical signal comprises an intensity that is lower than an activation threshold of tissue of the patient.

28. The method of claim 1, modifying the at least one of the stimulation parameter with which the second implantable medical device (IMD) generates electrical stimulation that is delivered to the tissue site or the sensing parameter with which the first IMD senses the first electrical signal based on the comparison comprises modifying the stimulation parameter.

29. The method of claim 1, modifying the at least one of the stimulation parameter with which the second implantable medical device (IMD) generates electrical stimulation that is delivered to the tissue site or the sensing parameter with which the first IMD senses the first electrical signal based on the comparison comprises modifying the sensing parameter.

30. A system comprising:

a first implantable medical device (IMD) that senses a first electrical signal within a patient;

a second IMD that delivers a second electrical signal to a tissue site within patient, wherein the first IMD senses the first electrical signal while the second IMD delivers the second electrical signal to the patient; and

a processor that determines a characteristic of the first electrical signal, compares the characteristic to a threshold value, and modifies at least one of a stimulation parameter with which the second IMD generates electrical stimulation therapy or a sensing parameter with which the first IMD senses the first electrical signal based on the comparison.

31. The system of claim 30, wherein the first implantable medical device delivers at least one of pacing, cardioversion or defibrillation therapy to a heart of the patient.

32. The system of claim 30, wherein the second implantable medical device delivers at least one of pacing, cardioversion or defibrillation therapy to a heart of the patient.

33. The system of claim 30, wherein the tissue site comprises at least one of a nonmyocardial tissue site or a nonvascular cardiac tissue site within the patient.

34. The system of claim 30, further comprising a medical device programmer that comprises the processor.

35. The system of claim 34, wherein the medical device programmer comprises a display, and the processor presents a waveform indicative of the first electrical signal on the display.

36. The system of claim 30, wherein the first implantable medical device comprises the processor.

37. The system of claim 30, wherein the second implantable medical device comprises the processor.

38. The system of claim 30, wherein the processor determines the characteristic of the first electrical signal by at least determining a value indicative of a difference between an amplitude of the first electrical signal and a sensing threshold of the first implantable medical device.

39. The system of claim 30, wherein the processor determines the characteristic of the first electrical signal by at least controlling the second implantable medical device (IMD) to suspend delivery of the second electrical signal, controlling the first IMD to sense a third electrical signal, controlling the second IMD to deliver the second electrical signal to the patient after the first IMD senses the third electrical signal, controlling the first IMD to sense the first electrical signal, and determining a difference between at least one signal characteristic of the first and third electrical signals.

40. The system of claim 39, wherein the processor determines the difference between at least one signal characteristic of the first and third electrical signals by at least determining a first value indicative of a difference between a first amplitude of the first electrical signal and a sensing threshold of the first implantable medical device (IMD), determining a second value indicative of a difference between a second amplitude of the third electrical signal and the sensing threshold of the first IMD, and determining the difference between the first and second values.

41. The system of claim 40, wherein the processor compares the characteristic of the first electrical signal to the threshold value by at least determining whether the difference between the first and second values is greater than or equal to the threshold value.

42. The system of claim 41, wherein the threshold value is less than the sensing threshold of the first implantable medical device.

43. The system of claim 39, wherein the processor determines the difference between at least one signal characteristic of the first and third electrical signals comprises by at least determining a difference between one or more frequency band characteristics of the first and third electrical signals.

44. The system of claim 30, wherein the characteristic of the first electrical signal comprises at least one of a mean or median peak-to-peak amplitude, a greatest peak-to-peak amplitude, or a root means square amplitude, a greatest peak-to-peak amplitude over a predetermined period of time, or a predetermined percentage of the greatest peak-to-peak amplitude.

45. The system of claim 30, wherein the processor determines the characteristic of the first electrical signal comprises by determining a first characteristic of the first electrical signal at a first time, and modifies the at least one of the stimulation parameter or the sensing parameter by at least modifying the stimulation parameter, wherein the processor controls the second implantable medical device (IMD) to deliver a third electrical signal to the patient according to the at least one modified stimulation parameter, determines a second characteristic of a fourth electrical signal sensed by the first IMD at a second time after the first time while the second IMD is delivering the third electrical signal, and determines whether a second characteristic signal is greater than or equal to the threshold value.

46. The system of claim 45, wherein the processor modifies at least one stimulation parameter by at least modifying a first value of a first stimulation parameter value, and wherein, if the second characteristic is greater than or equal to the threshold value, the processor modifies a second value of a second stimulation parameter with which the second implantable medical device generates the electrical stimulation, wherein the first and second stimulation parameters are different.

47. The system of claim 45, wherein the processor controls the second implantable medical device to suspend the delivery of electrical stimulation if the second characteristic is greater than or equal to the threshold value.

48. The system of claim 30, wherein the processor compares the characteristic to the threshold value by at least determining whether the characteristic is greater than or equal to a first threshold value, wherein if the characteristic is greater than or equal to the first threshold value, the processor determines whether the characteristic is greater than or equal to a second threshold value that is different than the first threshold value, generates a first category indication if the characteristic is not greater than or equal to the second threshold value, and generates generating a second category indication if the characteristic is greater than or equal to the second threshold value.

49. The system of claim 30, wherein the first implantable medical device senses the first electrical signal during a quiet segment of a cardiac cycle of a heart of the patient.

50. The system of claim 30, wherein the second electrical signal comprises intensity that is lower than an activation threshold of tissue of the patient.

51. The system of claim 30, wherein the processor compares the characteristic of the first electrical signal to the threshold value by at least determining whether the characteristic is greater than or equal to the threshold value, and wherein the processor generates and stores an interference indication if the characteristic is greater than or equal to the threshold value.

52. The system of claim 51, wherein the processor generates the interference indication by at least changing a property of the interference indication based on the difference between the characteristic of the first electrical signal and the threshold value.

53. The system of claim 52, wherein the property comprises at least one of an intensity of a visible characteristic of the interference indication, an audible characteristic of the interference indication or a somatosensory characteristic of the interference indication.

54. The system of claim 30, wherein the stimulation parameter comprises at least one of a current amplitude, a voltage amplitude, a pulse width, a pulse rate, a frequency, a duty cycle or an electrode combination.

55. The system of claim 30, wherein the sensing parameter comprises at least one of a sensing threshold value, an amplifier gain, a sensing vector, filter characteristic, or a type of physiological parameter of the patient that is sensed by the first implantable medical device.

56. The system of claim 55, wherein the filter characteristic comprises a type of filter applied by the first implantable medical device to the sensed first electrical signal.

57. A system comprising:

means for determining a characteristic of a first electrical signal sensed by a first implantable medical device (IMD) while a second IMD is delivering a second electrical signal to a tissue site within a patient, wherein the first and second IMDs are implanted within the patient;

means for comparing the characteristic of the first electrical signal to a threshold value; and

means for modifying at least one of a stimulation parameter with which the second IMD generates electrical stimulation that is delivered to the tissue site or a sensing parameter with which the first IMD senses the first electrical signal based on the comparison.

58. The system of claim 57, wherein the means for determining the characteristic of the first electrical signal comprises:

means for suspending delivery of the second electrical signal by the second implantable medical device (IMD);

means for sensing a third electrical signal with the first IMD;

means for activating the delivery of the second electrical signal by the second IMD;

means for sensing the first electrical signal with the first IMD while second IMD delivers the second electrical signal to the tissue site; and

means for determining a difference between at least one signal characteristic of the first and third electrical signals.

59. The system of claim 57, wherein the means for determining the characteristic of the first electrical signal comprises means for determining a value indicative of a difference between a first amplitude of the first electrical signal and a sensing threshold of the first implantable medical device.

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

determine a characteristic of a first electrical signal sensed by a first implantable medical device (IMD) while a second IMD is delivering a second electrical signal to a tissue site within a patient, wherein the first and second IMDs are implanted within the patient;

compare the characteristic of the first electrical signal to a threshold value; and

modify at least one of a stimulation parameter with which the second IMD generates electrical stimulation that is delivered to the tissue site or a sensing parameter with which the first IMD senses the first electrical signal based on the comparison.

61. The computer-readable medium of claim 60, wherein the instructions cause the processor to determine the characteristic of the first electrical signal by at least controlling the second implantable medical device (IMD) to suspend the delivery of the second electrical signal, control the first IMD to sense a third electrical signal, activate the delivery of the second electrical signal by the second IMD, control the first IMD to sense the first electrical signal with the first IMD while second IMD delivers the second electrical signal to the tissue site, and determining a difference between at least one signal characteristic of the first and third electrical signals.

62. A method comprising evaluating crosstalk between a first implantable medical device (IMD) implanted within a patient and a second IMD implanted within the patient with an external device, wherein the external device:

determines a characteristic of a first electrical signal sensed by the first IMD while a second IMD is delivering a second electrical signal to a tissue site within a patient;

compares the characteristic of the first electrical signal to a threshold value; and

modifies at least one of a stimulation parameter with which the second IMD generates electrical stimulation that is delivered to the tissue site or a sensing parameter with which the first IMD senses the first electrical signal based on the comparison.