System and method for closed-loop neural stimulation

• US 20060135998A1
• Filed: 11/16/2005
• Published: 06/22/2006
• Est. Priority Date: 11/18/2004
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Moffitt, Julia, Kramer, Andrew P., Libbus, Imad
• Granted Patent: US 8,332,047 B2
• Time in Patent Office: Days
• US Class Current: 607/2
• CPC Class Codes: A61N 1/36053 adapted for vagal stimulation A61N1/36114 takes precedence
• CPC Class Codes: A61N 1/36117 for treating hypertension

Abstract

Various device embodiments comprise a pulse generator, a signal processing module and a controller. The pulse generator is adapted to provide a neural stimulation signal to be applied at a neural simulation site within an autonomic nervous system (ANS). The signal processing module is adapted to receive and process sensed neural traffic at a neural sensing site within the ANS. The controller is connected to the pulse generator and adapted to provide a neural stimulation control signal to the pulse generator to generate the neural stimulation signal, and to the signal processing module to receive a feedback control signal indicative of the sensed neural traffic. The controller is adapted to adjust the neural stimulation control signal to adjust at least one parameter of the neural stimulation signal to converge on desired sensed neural traffic at the neural sensing site. Other aspects and embodiments are provided herein.

Claims

1. A device, comprising:

a pulse generator adapted to provide a neural stimulation signal to be applied at a neural simulation site within an autonomic nervous system (ANS);

a signal processing module adapted to receive and process sensed neural traffic at a neural sensing site within the ANS; and

a controller connected to the pulse generator and adapted to provide a neural stimulation control signal to the pulse generator to generate the neural stimulation signal and connected to the signal processing module to receive a feedback control signal indicative of the sensed neural traffic, the controller being adapted to adjust the neural stimulation control signal to adjust at least one parameter of the neural stimulation signal to converge on desired sensed neural traffic at the neural sensing site.

2. The device of claim 1, wherein the neural stimulation site within the ANS is a parasympathetic neural stimulation site and the neural sensing site within the ANS is a parasympathetic neural sensing site, the controller being adapted to receive the feedback control signal as negative feedback to adjust the at least one parameter of the neural stimulation signal to converge on the desired sensed neural traffic at the parasympathetic neural sensing site.

3. The device of claim 2, wherein the parasympathetic neural stimulation site is the parasympathetic neural sensing site.

4. The device of claim 3, wherein the parasympathetic neural stimulation site and the parasympathetic neural sensing site includes a baroreceptor site.

5. The device of claim 4, further comprising a sensor to sense cardiac cycles connected to the controller, wherein the controller is adapted to neural stimulate the baroreceptor site during one cardiac cycle and sense neural activity during another cardiac cycle.

6. The device of claim 2, wherein the parasympathetic neural stimulation site is a different site than the parasympathetic neural sensing site.

7. The device of claim 6, wherein the parasympathetic neural stimulation site includes at least one of a vagus nerve and a cardiac fat pad, and the parasympathetic neural sensing site includes a baroreceptor site.

8. The device of claim 2, wherein the parasympathetic neural stimulation site includes a first site on a vagus nerve, and the parasympathetic neural sensing site includes a second site on the vagus nerve.

9. The device of claim 8, wherein one of the first site and the second site is an efferent site and the other is an afferent site.

10. The device of claim 8, wherein both the first and second sites are afferent sites on the vagus nerve.

11. The device of claim 8, wherein both the first and second sites are efferent sites on the vagus nerve.

12. The device of claim 1, wherein the neural stimulation site within the ANS is a sympathetic neural stimulation site and the neural sensing site within the ANS is a sympathetic neural sensing site, the controller being adapted to receive the feedback control signal as negative feedback to adjust the at least one parameter of the neural stimulation signal to converge on the desired sensed neural traffic at the sympathetic neural sensing site.

13. The device of claim 12, wherein both the neural stimulation site and the neural sensing site include a cardiac sympathetic nerve branch.

14. The device of claim 1, wherein the neural stimulation site within the ANS is a parasympathetic neural stimulation site and the neural sensing site within the ANS is a sympathetic neural sensing site, the controller being adapted to receive the feedback control signal as positive feedback to adjust the at least one parameter of the neural stimulation signal to converge on the desired sensed neural traffic at the sympathetic neural sensing site

15. The device of claim 14, wherein the parasympathetic neural stimulation site includes a vagus nerve site.

16. The device of claim 14, wherein the parasympathetic neural stimulation site includes a baroreceptor site and the sympathetic neural sensing site includes a cardiac sympathetic nerve branch.

17. The device of claim 1, wherein the neural stimulation site within the ANS is a sympathetic neural stimulation site within the ANS and the neural sensing site is a parasympathetic neural sensing site, the controller being adapted to receive the feedback control signal as positive feedback to adjust the at least one parameter of the neural stimulation signal to converge on the desired sensed neural traffic at the parasympathetic neural sensing site.

18. The device of claim 17, wherein the sympathetic neural stimulation site includes a cardiac sympathetic nerve branch, and the parasympathetic neural sensing site includes a baroreceptor site.

19. The device of claim 1, further comprising a dynamic input control signal, the controller being adapted to receive the dynamic input control signal to adjust a target for the sensed neural traffic.

20. The device of claim 1, further comprising a gain input control signal to adjust gain, the controller being adapted to receive the gain input control signal to increment and decrement a gain for an intensity of the neural stimulation based on the feedback control signal.

21. The device of claim 20, further comprising a dynamic input control signal, the controller being adapted to receive the dynamic input control signal to adjust the gain.

22. The device of claim 1, further comprising an associated input control signal, the controller being adapted to receive the associated input control signal to associate the sensed neural activity to a neural stimulation event.

23. The device of claim 1, further comprising a dynamic input control signal, a gain input control signal, and an associated input control signal, the controller being adapted to associate the sensed neural activity to a neural stimulation event using the associated input control signal to verify a causal relationship between sensed and stimulated neural activity, to receive the gain input control signal to increment and decrement a gain for an intensity of the neural stimulation based on the feedback control signal, and to receive the dynamic input control signal to adjust a target for the sensed neural traffic and to adjust the gain.

24. The device of claim 1, wherein the neural simulation site is on a neural pathway and the neural sensing site is on the same neural pathway.

25. The device of claim 1, wherein the neural simulation site is at the neural sensing site.

26. An implantable medical device, comprising:

a neural stimulator adapted to provide a neural stimulation signal to be applied at a neural simulation site within an autonomic nervous system (ANS);

a neural sensor and signal processing module adapted to receive and process sensed neural traffic at a neural sensing site within the ANS; and

controller circuitry connected to the pulse generator and adapted to provide a neural stimulation control signal to the pulse generator to generate the neural stimulation signal and connected to the signal processing module to receive a feedback indicative of the sensed neural traffic, the controller including;

a feedback comparator adapted to receive a processed sensed signal from the neural sensor and signal processing module, to receive a target signal for the processed sensed signal, and to compare the processed sensed signal to the target signal and generate a corresponding feedback signal; and

a neural controller adapted to receive the feedback signal and generate the stimulation control signal using the feedback signal.

27. The device of claim 26, further comprising a dynamic input module to produce a dynamic control signal based on at least one of a physiological sensed parameter and a time signal, the controller circuitry further comprising an associator to produce an associated result control signal verifying a causal relationship between sensed and stimulated neural activity, the neural controller being adapted to receive the dynamic control signal and the associated result signal and generate the stimulation control signal using the feedback signal, the dynamic control signal and the associated result signal.

28. The device of claim 27, wherein the controller circuitry includes memory adapted to store programmable parameters related to sensing neural traffic, providing neural stimulation, and generating the dynamic control signal.

29. A method, comprising:

sensing nerve traffic at a first autonomic nervous system (ANS) site;

generating a feedback signal indicative of at least one parameter derived from sensed nerve traffic at the first ANS site;

generating a neural stimulation control signal with stimulation settings using the feedback signal; and

generating a neural stimulation signal with a controlled neural stimulation intensity at a second ANS site using the neural stimulation control signal.

30. The method of claim 29, wherein generating a neural stimulation control signal includes:

maintaining the stimulation settings of the neural stimulation control signal if the at least one parameter derived from sensed nerve traffic at the first ANS site is within a target range; and

adjusting the stimulation settings of the neural stimulation control signal if the at least one parameter derived from sensed nerve traffic at the first ANS site is within a target range.

31. The method of claim 29, wherein generating the neural stimulation control signal further includes generating the neural stimulation control signal using the feedback control signal and a dynamic input control signal.

32. The method of claim 29, wherein generating the neural stimulation control signal further includes generating the neural stimulation control signal using the feedback control signal and an associated control signal verifying a causal relationship between sensed activity and stimulation events.

33. The method of claim 29, wherein generating the neural stimulation control signal further includes generating the neural stimulation control signal using the feedback control signal, a dynamic input control signal and an associated control signal verifying a causal relationship between sensed activity and stimulation events.

34. The method of claim 29, wherein both the first ANS site and the second ANS site include a sympathetic site, and generating the neural stimulation control signal using the feedback signal includes providing negative feedback control using the feedback signal.

35. The method of claim 29, wherein both the first ANS site and the second ANS site include a parasympathetic site, and generating the neural stimulation control signal using the feedback signal includes providing negative feedback control using the feedback signal.

36. The method of claim 29, wherein one of the first ANS site and the second ANS site includes a parasympathetic site and the other of the first ANS site and the second ANS site includes a sympathetic site, and generating the neural stimulation control signal using the feedback signal includes providing positive feedback control using the feedback signal.