AUTOMATIC ELECTRODE INTEGRITY MANAGEMENT SYSTEMS AND METHODS

• US 20070293903A1
• Filed: 06/16/2006
• Published: 12/20/2007
• Est. Priority Date: 06/16/2006
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Bohn, Derek D., Brooke, M. Jason, Gandhi, Rajesh Krishan, Sathaye, Alok S., McCabe, Aaron
• Granted Patent: US 7,899,535 B2
• Time in Patent Office: Days
• US Class Current: 607/27
• CPC Class Codes: A61N 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence
• CPC Class Codes: A61N 1/36842 Multi-site stimulation in the same chamber
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation
• CPC Class Codes: A61N 1/3706 Pacemaker parameters stimulation threshold A61N1/371
• CPC Class Codes: A61N 1/37282 characterised by communication with experts in remote locations using a network

Abstract

This document discusses, among other things, systems and methods for automatic electrode integrity management. Interelectrode impedance is measured for various electrode combinations of an implantable cardiac function management device. The impedance data is processed, such as at an external remote server, to determine whether an electrode is failing or has failed, to select an alternate electrode configuration, to alert a physician or patient, to predict a time-to-failure such as by using population data, or to reprogram electrode configuration or other device parameters of the implantable cardiac function management device.

Claims

1. A method comprising:

selecting a first combination of at least two electrodes for sensing or delivering an electrical energy from or to a heart, respectively, the first combination including one or more commonly connected first electrodes and one or more commonly connected second electrodes that are unconnected to the first electrodes;

determining a first impedance between the first electrodes and the second electrodes;

comparing the first impedance to one or more criteria to determine whether the first combination is adequate for the sensing or delivering the electrical energy;

if the first combination is determined to be inadequate, then selecting between at least second and third combinations of at least two electrodes to determine which is more suitable for the sensing or delivering the electrical energy, the second combination of at least two electrodes including one or more commonly connected third electrodes and one or more commonly connected fourth electrodes that are unconnected to the third electrodes, the third combination of at least two electrodes including one or more commonly connected fifth electrodes and one or more commonly connected sixth electrodes that are unconnected to the fifth electrodes, the selecting including;

determining a second impedance between the third electrodes and the fourth electrodes of the selected second combination of at least two electrodes;

determining a third impedance between the fifth electrodes and the sixth electrodes of the selected third combination of at least two electrodes; and

using the second and third impedance for the selecting between the at least second and third combinations; and

sensing or delivering electrical energy from or to the cardiac tissue using the selected one of the second and third combinations of electrodes.

2. The method of claim 1, comprising:

measuring at least one secondary characteristic, the secondary characteristic selected from at least one of a pacing threshold, a defibrillation threshold, a sensed depolarization amplitude, and a sensed signal-to-noise characteristic;

determining, using the secondary characteristic in combination with the measured first, second, or third impedance, at least one of;

(1) whether the first combination is adequate for the sensing or delivering the electrical energy; and

(2) which of the second and third combinations of at least two electrodes is more suitable for the sensing or delivering the electrical energy.

3. The method of claim 1, in which the comparing the first impedance to one or more criteria is performed at an implantable device.

4. The method of claim 1, in which the comparing the first impedance to one or more criteria is performed at a remote server.

5. The method of claim 1, in which at least two of the first electrodes, the second electrodes, the third electrodes, the fourth electrodes, the fifth electrodes, and the sixth electrodes include the same electrode.

6. A method comprising:

repeatedly measuring electrode impedances for combinations of two or more electrodes located in association with a heart;

recording, in a memory of an implantable cardiac device, information associated with the measured electrode impedances;

collecting, in an external data storage, the recorded information for two or more implantable cardiac devices;

creating one or more electrode impedance relationships for at least one of the implantable cardiac devices using the external database; and

sending information to an implantable cardiac device that is derived from at least one of the electrode impedance relationships.

7. The method of claim 6, comprising:

measuring at least one secondary characteristic, the secondary characteristic selected from at least one of a pacing threshold, a defibrillation threshold, a sensed depolarization amplitude, and a sensed signal-to-noise characteristic;

determining, using the secondary characteristic in combination with the measured electrode impedances for the combinations of two or more electrodes associated with the heart, a suitability of at least one of the combinations of two or more electrodes for sensing electrical energy from or delivering electrical energy to the heart.

8. The method of claim 7, comprising comparing, using the secondary characteristic in combination with the measured electrode impedances for the combinations of two or more electrodes associated with the heart, combinations of two or more electrodes to determine suitability for sensing electrical energy from or delivering electrical energy to the heart.

9. The method of claim 6, in which the recording includes storing at least one measured electrode impedance and corresponding measurement time, and further comprising transmitting the recorded measured electrode impedance and corresponding measurement time to an external device, and in which the creating at least one electrode impedance relationship includes creating an impedance trend over time.

10. The method of claim 6, in which the creating at least one electrode impedance relationship includes generating one or more statistical ensembles of electrode impedances for the combinations of two or more electrode.

11. The method of claim 6, in which the creating at least one electrode impedance relationship includes determining a change in electrode impedance for at least one of the combinations of two or more electrodes.

12. The method of claim 6, in which the creating at least one electrode impedance relationship includes determining a historical impedance-electrode relationship for at least one of the combinations of two or more electrodes.

13. The method of claim 6, in which the creating at least one electrode impedance relationship includes estimating a future electrode impedance value for at least one of the combinations of two or more electrodes.

14. The method of claim 6, in which the creating at least one electrode impedance relationship includes determining an order of electrode combinations for sensing or delivery an electrical energy.

15. The method of claim 6, in which the creating at least one electrode impedance relationship includes determining a population estimate of electrode impedances for similar electrodes used in various patients in a patient population.

16. The method of claim 15, comprising downloading information from the population estimate to the implantable cardiac device.

17. The method of claim 16, comprising using the downloaded information at the implantable cardiac device to determine the existence of an actual or impending lead failure.

18. The method of claim 16, comprising using the downloaded information at the implantable cardiac device to determine a response to an actual or impending lead failure.

19. A system comprising:

an implantable cardiac function management device, configured to be coupled to combinations of at least two electrodes for sensing electrical energy from or delivering electrical energy to a heart, the cardiac function management device comprising;

an electrode impedance measurement circuit, for determining a first impedance between one or more commonly connected first electrodes and one or more commonly connected second electrodes;

a memory, communicatively coupled to the electrode impedance measurement circuit, the memory configured to store impedance information;

a processor, communicatively coupled to the memory, the processor configured to select between electrode configurations, and to substitute a backup electrode configuration for a failed or failing electrode configuration, the backup configuration selected from multiple candidate electrode configurations by using measured impedances of the candidate electrode configurations.

20. The system of claim 19, in which the implantable device comprises at least one measurement circuit that is configured to measure at least one secondary characteristic, the secondary characteristic selected from at least one of a pacing threshold, a defibrillation threshold, a sensed depolarization amplitude, and a sensed signal-to-noise characteristic, and wherein the processor is configured to determine, using the secondary characteristic in combination with the measured impedances of the candidate electrode configurations, at least one of:

(1) whether the first combination is adequate for the sensing or delivering the electrical energy; and

(2) which of the second and third combinations of at least two electrodes is more suitable for the sensing or delivering the electrical energy.

21. The system of claim 19, wherein the implantable cardiac function management device includes a communication circuit, coupled to the processor, the communication circuit configured for communication with a remote external server, and wherein the processor of the implantable cardiac function management device is configured to use population impedance information received from a remote server to determine at least one of:

(1) whether an electrode combination being used by at least one of the devices is failing or failed, or (2) a suitable backup electrode combination selected from the candidate back up electrode combinations.

22. The system of claim 19, wherein the implantable cardiac function management device includes a communication circuit, coupled to the processor, the communication circuit configured for communication with a remote external server to communicate information about the first impedance to the remote external server.

23. A system comprising:

an external remote server, configured to be communicatively coupled to a set of implantable cardiac function management devices for obtaining impedance measurements from electrode combinations of each of the set of devices, the server comprising;

a data storage, the data storage comprising an individual data storage for the measured electrode impedances of each of the set of devices; and

a processor, configured to use the impedance measurements to detect a failed or failing electrode combination being used by at least one of the devices, and configured to select a backup electrode combination for the failed or failing electrode combination using impedance measurements for candidate backup electrode combinations.

24. The system of claim 23, in which the server comprises:

a population data storage for measured or predicted population impedance information associated with the set of devices; and

wherein the processor is configured to use the population impedance information to determine at least one of;

(1) whether an electrode combination being used by at least one of the devices is failing or failed, or (2) a suitable backup electrode combination selected from the candidate back up electrode combinations.

25. The system of claim 23, in which the server is communicatively coupled to receive secondary information from the set of devices, the secondary information selected from a pacing threshold, a defibrillation threshold, a sensed depolarization amplitude, and a sensed signal-to-noise characteristic, and wherein the data storage is configured to store the secondary information, and wherein the processor is configured to use the secondary information in combination with the impedance to determine at least one of:

(1) whether an electrode combination being used by at least one of the devices is failing or failed, or (2) a suitable backup electrode combination selected from the candidate back up electrode combinations.