Method and Apparatus for Phrenic Stimulation Detection

• US 20090210024A1
• Filed: 02/10/2009
• Published: 08/20/2009
• Est. Priority Date: 02/14/2008
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: M., Brooke Jason
• Granted Patent: US 8,649,866 B2
• Time in Patent Office: Days
• US Class Current: 607/28
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1107 Measuring contraction of parts of the body, e.g. organ, muscle apparatus for measuring work or force in general G01L
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4029 for evaluating the peripheral nervous systems A61B5/24 takes precedence
• CPC Class Codes: A61B 5/4848 Monitoring or testing the effects of treatment, e.g. of medication
• CPC Class Codes: A61N 1/3601 of respiratory organs
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• 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 1/371 Capture, i.e. successful stimulation
• CPC Class Codes: A61N 1/3712 Auto-capture, i.e. automatic adjustment of the stimulation threshold
• CPC Class Codes: A61N 1/372 Arrangements in connection with the implantation of stimulators

Abstract

Approaches for characterizing a phrenic stimulation threshold, a cardiac capture threshold, a maximum device parameter, and a minimum device parameter are described. A plurality of cardiac pacing pulses can be delivered by using a cardiac pacing device, a pacing parameter of the plurality of cardiac pacing pulses being changed between delivery of at least some of the pulses. One or more sensor signals can be evaluated to detect stimulation of the phrenic nerve by one or more of the plurality of cardiac pacing pluses. The evaluation of the one or more sensor signals and the pacing parameter can be compared to determine if a phrenic stimulation threshold is at least one of higher than a maximum device parameter and lower than a minimum device parameter.

Claims

1. A method, comprising:

delivering a plurality of cardiac pacing pulses using a cardiac pacing device, a pacing parameter of the plurality of cardiac pacing pulses being changed between delivery of at least some of the pulses;

evaluating one or more sensor signals to detect stimulation of the phrenic nerve by one or more of the plurality of cardiac pacing pluses; and

comparing the evaluation of the one or more sensor signals and the pacing parameter of one or more of the plurality of cardiac pacing pulses to determine if a phrenic stimulation threshold is at least one of higher than a maximum device parameter and lower than a minimum device parameter.

2. The method of claim 1, wherein the maximum device parameter is a maximum amplitude or width of a pacing pulse that the cardiac pacing device is programmed to deliver and the minimum device parameter is a minimum amplitude or width of a pacing pulse that the cardiac pacing device is programmed to deliver.

3. The method of claim 1, wherein delivering the plurality of cardiac pacing pulses comprises increasing a pacing pulse amplitude or width parameter for one or more of the plurality of cardiac pacing pulses between delivery of the at least some pulses until at least one of the phrenic stimulation threshold is detected and a cardiac pacing pulse is delivered at maximum amplitude or width that the device is programmed to deliver.

4. The method of claim 1, wherein delivering the plurality of cardiac pacing pulses comprises delivering an initial pacing pulse having an amplitude or width parameter at or above the cardiac capture threshold and increasing the pacing pulse amplitude or width parameter for one or more of the plurality of cardiac pacing pulses between delivery of the at least some pulses until at least one of the phrenic stimulation threshold is detected and a cardiac pacing pulse is delivered at maximum amplitude or width that the device is programmed to deliver.

5. The method of claim 1, wherein delivering the plurality of cardiac pacing pulses comprises delivering an initial pacing pulse having an amplitude or width at a programmed device minimum and increasing the pacing pulse amplitude or width for one or more of the plurality of cardiac pacing pulses between delivery of the at least some pulses until at least one of the phrenic stimulation threshold is detected and a cardiac pacing pulse is delivered at a maximum amplitude or width that the device is programmed to deliver.

6. The method of claim 1, wherein delivering the plurality of cardiac pacing pulses comprises decreasing a pacing pulse amplitude or width parameter for one or more of the plurality of cardiac pacing pulses between delivery of the at least some pulses until the pacing pulse amplitude or width parameter is decreased to at least one of the cardiac capture threshold and the minimum device amplitude or width that the device is programmed to deliver.

7. The method of claim 1, further comprising reprogramming one or both of the maximum device parameter and the minimum device parameter based on the determination that the phrenic stimulation threshold is at least one of higher than the maximum device parameter and lower then the minimum device parameter.

8. The method of claim 1, further comprising establishing a parameter range limit comprising the maximum device parameter and the minimum device parameter, wherein at least one of the plurality of cardiac pacing pulses is delivered having a pacing parameter outside of the parameter range limit.

9. The method of claim 8, further comprising changing the parameter range limit based on the comparison of the evaluation of the one or more sensor signals and the pacing parameter of the at least one cardiac pacing pulse having the pacing parameter outside of the parameter range limit.

10. The method of claim 1, further comprising changing one or both of an increment value and a decrement value for the pacing parameter of the plurality of cardiac pacing pulses that is changed between delivery of the at least some of the pulses based on the comparison of the evaluation of the one or more sensor signals and the pacing parameter of one or more of the plurality of cardiac pacing pulses.

11. The method of claim 1, further comprising identifying relative relationships between each of the phrenic stimulation threshold, the maximum device parameter, the minimum device parameter, and the cardiac capture threshold based on the comparison of the evaluation of the one or more sensor signals and the pacing parameter of one or more of the plurality of cardiac pacing pulses.

12. The method of claim 9, further comprising selecting a pulse amplitude or width parameter range for delivering pacing pulses associated with a therapy, the pulse amplitude or width parameter range selection based on the identified relationships between the phrenic stimulation threshold, the maximum device parameter, the minimum device parameter, and the cardiac capture threshold.

13. A cardiac rhythm management system, comprising:

an implantable cardiac pacing device having a plurality of electrodes;

circuitry configured to output a plurality of cardiac pacing pulses through the electrodes and modify one or more pacing parameters of the plurality of cardiac pacing pulses;

one or more sensors configured to sense stimulation of the phrenic nerve by one or more of the plurality of pacing pulses and provide one or more signals based on the sensed phrenic stimulation; and

a controller configured to execute program instructions stored in memory to cause the system to compare the one or more signals and the one or more pacing parameters to determine if a phrenic stimulation threshold is at least one of higher than a maximum cardiac pacing parameter and lower than a minimum cardiac pacing parameter, and store information based on the determination.

14. The cardiac rhythm management system of claim 13, wherein the maximum cardiac pacing parameter is a maximum pacing pulse amplitude or width that the cardiac pacing device is programmed to deliver and the minimum cardiac pacing parameter is a minimum pacing pulse amplitude or width that the cardiac pacing device is programmed to deliver.

15. The cardiac rhythm management system of claim 13, wherein the controller is further configured to execute stored program instructions to cause the system to increase a pacing pulse amplitude or width parameter for one or more of the plurality of cardiac pacing pulses between delivery of at least some of the plurality of pulses until at least one of the phrenic stimulation threshold is detected and a cardiac pacing pulse is delivered at maximum amplitude or width that the cardiac pacing device is programmed to deliver.

16. The cardiac rhythm management system of claim 13, wherein the controller is further configured to execute stored program instructions to cause the system to deliver an initial pacing pulse through the electrodes having an amplitude or width at or above the cardiac capture threshold and increase the pacing pulse amplitude or width for one or more of the plurality of cardiac pacing pulses between delivery of at least some of the plurality of pulses until at least one of the phrenic stimulation threshold is detected and a cardiac pacing pulse is delivered at maximum amplitude or width that the cardiac pacing device is programmed to deliver.

17. The cardiac rhythm management system of claim 13, wherein the controller is further configured to execute stored program instructions to cause the system to deliver an initial pacing pulse having an amplitude or width at a programmed minimum level and increase the pacing pulse amplitude or width for one or more of the plurality of cardiac pacing pulses between delivery of at least some of the plurality of pulses until at least one of the phrenic stimulation threshold is detected and a cardiac pacing pulse is delivered at maximum amplitude or width that the cardiac pacing device is programmed to deliver.

18. The cardiac rhythm management system of claim 13, wherein the controller is further configured to execute stored program instructions to cause the system to decrease a pacing pulse amplitude or width parameter for one or more of the plurality of cardiac pacing pulses between delivery of at least some of the plurality of pulses until the pacing pulse amplitude or width parameter is decreased to at least one of the cardiac capture threshold and the minimum cardiac pacing amplitude or width parameter that the cardiac pacing device is programmed to deliver.

19. The cardiac rhythm management system of claim 13, wherein the controller is further configured to execute stored program instructions to cause the system to identify relative relationships between each of the phrenic stimulation threshold, the maximum cardiac pacing parameter, the minimum cardiac pacing parameter, and the cardiac capture threshold.

20. The cardiac rhythm management system of claim 19, wherein the controller is further configured to execute stored program instructions to cause the system to select a pulse amplitude or width parameter range for delivering cardiac pacing pulses associated with a therapy, the pulse amplitude or width parameter range selection based on the identified relationships between the phrenic stimulation threshold, the maximum cardiac pacing parameter, the minimum cardiac pacing parameter, and the cardiac capture threshold.

21. The cardiac rhythm management system of claim 13, wherein the controller is further configured to execute stored program instructions to cause the system to reprogram one or both of the maximum cardiac pacing parameter and the minimum cardiac pacing parameter based on the determination that the phrenic stimulation threshold is at least one of higher than the maximum cardiac pacing parameter and lower then the minimum cardiac pacing parameter.

22. The cardiac rhythm management system of claim 13, wherein the controller is further configured to execute stored program instructions to cause the system to select a parameter range limit comprising the maximum cardiac pacing parameter and the minimum cardiac pacing parameter and deliver at least one of the plurality of cardiac pacing pulses with a pacing parameter that is outside of the parameter range limit.

23. The cardiac rhythm management system of claim 22, wherein the controller is further configured to execute stored program instructions to cause the system to change the parameter range limit based on the comparison of the one or more sensor signals and the pacing parameter of the at least one cardiac pacing pulses with the pacing parameter that is outside of the parameter range limit.

24. The cardiac rhythm management system of claim 13, wherein the controller is further configured to execute stored program instructions to cause the system to change one or both of an increment value and a decrement value for the pacing parameter of the plurality of cardiac pacing pulses that is changed between delivery of at least some of the pulses based on the comparison of the evaluation of the one or more sensor signals and the pacing parameter of one or more of the plurality of cardiac pacing pulses.

25. A cardiac rhythm management system, comprising:

an implantable cardiac pacing device having a plurality of electrodes;

means for delivering a plurality of cardiac pacing pulses through the plurality of electrodes and modifying one or more pacing parameters of the plurality of cardiac pacing pulses;

means for sensing stimulation of the phrenic nerve by one or more of the plurality of pacing pulses and provide one or more signals based on the sensed phrenic stimulation; and

means for comparing the evaluation of the one or more sensor signals and the one or more pacing parameters to determine if a phrenic stimulation threshold is at least one of higher than a maximum programmed device parameter and lower than a minimum programmed device parameter.