Systems and methods for providing neural stimulation transitions

• US 8,249,717 B2
• Filed: 07/18/2007
• Issued: 08/21/2012
• Est. Priority Date: 07/18/2007
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Brockway, Marina V., Haefner, Paul A., Caparso, Anthony V., Tesfavesus, Wondimeneh
• Primary Examiner(s): Lavert, Nicole F
• Application Number:
  US11/779,764
• Publication Number:
  US 20090024186A1
• Time in Patent Office: 1,861 Days
• Field of Search: 607/5, 607/45, 607/59
• US Class Current: 607/59
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/36117 for treating hypertension

Abstract

A method embodiment comprises generating a neural stimulation signal for a neural stimulation therapy. The signal is generated during a duty cycle of a stimulation period to provide the neural stimulation therapy with an intensity at a therapy level for a portion of the duty cycle. In various embodiments, a ramp up protocol is implemented to begin the duty cycle, a ramp down protocol is implemented to end the duty cycle, or both the ramp up protocol and the ramp down protocol are implemented. The ramp up protocol includes ramping up the intensity from a non-zero first subthreshold level for the neural stimulation therapy at the beginning of the duty cycle to the therapy level. The ramp down protocol includes ramping down the intensity from the therapy intensity level to a non-zero second subthreshold level for the neural stimulation therapy at the end of the duty cycle.

Claims

1. A method, comprising:

generating a neural stimulation signal only during a duty cycle of a stimulation period to provide intermittent neural stimulation for a neural stimulation therapy, including;

generating the neural stimulation signal during the duty cycle of the stimulation period to provide the neural stimulation therapy with an intensity at a therapy level for a portion of the duty cycle; and

implementing a ramp up protocol to begin the duty cycle, a ramp down protocol to end the duty cycle, or both the ramp up protocol to begin the duty cycle and the ramp down protocol to end the duty cycle;

wherein implementing the ramp up protocol includes stepping up the intensity from a zero value before the duty cycle when the neural stimulation signal is not generated to a non-zero first subthreshold level for the neural stimulation therapy at the beginning of the duty cycle and ramping up the intensity from the non-zero first subthreshold level at the beginning of the duty cycle to the therapy level; and

wherein implementing the ramp down protocol includes ramping down the intensity from the therapy level to a non-zero second subthreshold level for the neural stimulation therapy at the end of the duty cycle, and stepping down the neural stimulation intensity from the non-zero second subthreshold level for the neural stimulation therapy at the end of the duty cycle to the zero value after the duty cycle when the neural stimulation signal is not generated.

2. The method of claim 1, wherein the first subthreshold level is equal to the second subthreshold level.

3. The method of claim 1, further comprising stimulating an autonomic neural target using the neural stimulation signal.

4. The method of claim 3, wherein the autonomic neural target includes a vagus nerve.

5. The method of claim 1, further comprising programming at least one programmable parameter in an implantable medical device for the ramp up protocol, the ramp down protocol or both the ramp up and ramp down protocols using a patient external device.

6. The method of claim 1, further comprising monitoring a physiologic response to the end of the duty cycle, and automatically adjusting at least one adjustable parameter for the ramp up protocol, the ramp down protocol or both the ramp up and ramp down protocols using a patient external device.

7. The method of claim 1, further comprising monitoring a physiologic response to the end of the duty cycle, and automatically adjusting at least one adjustable parameter for the ramp up protocol, the ramp down protocol or both the ramp up and ramp down protocols using an internal device.

8. A method for operating an implantable neural stimulator with programmable parameters adapted to be programmed using a patient-external device, comprising:

programming at least one ramp parameter for neural stimulation intensity using the patient-external device;

generating a neural stimulation signal for a neural stimulation therapy, including;

generating the neural stimulation signal during a duty cycle of a stimulation period to provide the neural stimulation therapy with an intensity at a therapy level for a portion of the duty cycle; and

implementing a ramp up protocol or a ramp down protocol, wherein;

the ramp up protocol has at least one programmable ramp up parameter to begin the duty cycle, wherein implementing the ramp up protocol steps up the intensity of the neural stimulation therapy from a zero value to a non-zero first subthreshold value at the beginning of the duty cycle and ramps up the intensity of the neural stimulation therapy from the non-zero first subthreshold value to the therapy level, wherein the at least one programmable ramp up parameter includes a parameter selected from the group of parameters consisting of;

a first subthreshold level parameter for the neural stimulation therapy at the beginning of the duty cycle from which to ramp up to the therapy level; and

a ramp up duration parameter;

or

the ramp down protocol has programmable ramp down parameters to end the duty cycle, wherein implementing the ramp down protocol ramps down the intensity of the neural stimulation therapy from the therapy value to a non-zero second threshold value and steps down the intensity of the neural stimulation therapy from the second threshold value to the zero value at the end of the duty cycle, wherein the programmable ramp down parameter includes a parameter selected from the group of parameters consisting of;

a second subthreshold level parameter for the neural stimulation therapy at the end of the duty cycle to which to ramp down from the therapy level; and

a ramp down duration parameter.

9. The method of claim 8, wherein:

implementing includes implementing the ramp up protocol; and

programming includes programming both the first subthreshold level parameter and the ramp up duration parameter.

10. The method of claim 8, wherein:

implementing includes implementing the ramp down protocol; and

programming includes programming both the second subthreshold level parameter and the ramp down duration parameter.

11. The method of claim 8, wherein:

implementing includes implementing both the ramp up and ramp down protocols;

one programmable value provides a value for the first and second subthreshold level parameters; and

programming includes programming the one programmable value for the first and second subthreshold level parameters.

12. The method of claim 8, wherein:

implementing includes implementing both the ramp up and ramp down protocols;

one programmable value provides a value for the ramp up duration and ramp down duration parameters; and

programming includes programming the one programmable value for the ramp up duration and ramp down duration parameters.

13. A method for delivering neural stimulation to a neural target of a patient, comprising:

generating a neural stimulation signal only during a duty cycle of a stimulation period to provide intermittent neural stimulation for a neural stimulation therapy, including;

generating the neural stimulation signal during the duty cycle of the stimulation period to provide the neural stimulation therapy with an intensity at a therapy level for a portion of the duty cycle; and

implementing a ramp up protocol to begin the duty cycle, a ramp down protocol to end the duty cycle, or both the ramp up protocol to begin the duty cycle and the ramp down protocol to end the duty cycle, wherein the ramp up protocol is configured to step up the intensity of the neural stimulation therapy from a zero value before the duty cycle when the neural stimulation signal is not generated to a non-zero first subthreshold value at the beginning of the duty cycle and ramps up the intensity of the neural stimulation therapy from the non-zero first subthreshold value to the therapy level, wherein the ramp down protocol is configured to ramp down the intensity of the neural stimulation therapy from the therapy value to a non-zero second threshold value and step down the intensity of the neural stimulation therapy from the second threshold value at the end of the duty cycle to the zero value after the duty cycle when the neural stimulation signal is not generated;

monitoring a physiologic response to the end of the duty cycle; and

adjusting the ramp up protocol, the ramp down protocol, or both the ramp up protocol and ramp down protocol using the monitored physiologic response to the end of the duty cycle.

14. The method of claim 13, wherein:

the adjustable ramp up protocol includes an adjustable ramp up duration; and

adjusting includes adjusting the adjustable ramp up duration using the monitored physiologic response to the end of the duty cycle.

15. The method of claim 13, wherein:

the adjustable ramp up protocol includes an adjustable starting intensity level; and

adjusting includes adjusting the adjustable starting intensity level using the monitored physiologic response to the end of the duty cycle.

16. The method of claim 13, wherein:

the adjustable ramp down protocol includes an adjustable ramp down duration; and

adjusting includes adjusting the adjustable ramp down duration using the monitored physiologic response to the end of the duty cycle.

17. The method of claim 13, wherein:

the adjustable ramp down protocol includes an adjustable ending intensity level; and

adjusting includes adjusting the adjustable ending intensity level using the monitored physiologic response to the end of the duty cycle.

18. The method of claim 13, wherein:

monitoring includes monitoring a heart rate response or a blood pressure response to the end of the duty cycle.

19. A neural stimulator, comprising:

a neural stimulation delivery system adapted to generate a neural stimulation signal only during a duty cycle of a stimulation period to provide intermittent neural stimulation for a neural stimulation therapy; and

a controller adapted to control the neural stimulation delivery system to;

generate the neural stimulation signal during the duty cycle of the stimulation period to provide the neural stimulation therapy with an intensity at a therapy level for a portion of the duty cycle; and

implement a protocol selected from the group of protocols consisting of;

a ramp up protocol to begin the duty cycle by stepping up the intensity from a zero value before the duty cycle when the neural stimulation signal is not generated to a non-zero first subthreshold level for the neural stimulation therapy at the beginning of the duty cycle, and ramping up the intensity from the non-zero first subthreshold level for the neural stimulation therapy at the beginning of the duty cycle to the therapy level;

a ramp down protocol to end the duty cycle by ramping down the intensity from the therapy level to a non-zero second subthreshold level for the neural stimulation therapy and stepping down the neural stimulation therapy from the non-zero second subthreshold level at the end of the duty cycle to the zero value after the duty cycle when the neural stimulation signal is not generated; and

a protocol that includes both the ramp up protocol to begin the duty cycle and the ramp down protocol to end the duty cycle.

20. The stimulator of claim 19, wherein the first subthreshold level is equal to the second subthreshold level.

21. The stimulator of claim 19, further comprising an implantable housing to contain the neural stimulation delivery system and the controller.

22. The stimulator of claim 19, wherein the neural stimulation delivery system is adapted to generate the neural stimulation signal for a vagal stimulation therapy.

23. The stimulator of claim 19, further comprising a physiologic sensor adapted for use in sensing a physiologic response to the end of the duty cycle, wherein the controller is adapted to use the physiologic response to the end of the duty cycle to automatically adjust the ramp up protocol, automatically adjust the ramp down protocol, or automatically adjust both the ramp up protocol and the ramp down protocol.

24. The stimulator of claim 23, wherein:

the controller is adapted to automatically adjust at least one adjustable parameter to control the neural stimulation delivery system using the physiologic response to the end of the duty cycle; and

the at least one adjustable parameter selected from a group of parameters consisting of;

an adjustable ramp up duration;

an adjustable starting intensity level;

an adjustable ramp down duration; and

an adjustable ending intensity level.

25. The stimulator of claim 19, wherein:

the stimulator is an implantable stimulator and is adapted to receive programming instructions from an external device to program at least one programmable parameter;

the controller is adapted to use the at least one programmable parameter to control the neural stimulation delivery system;

the at least one programmable parameter selected from a group of parameters consisting of;

a programmable ramp up duration;

a programmable starting intensity level;

a programmable ramp down duration; and

a programmable ending intensity level.