Neurostimulation and recording of physiological response for the treatment of chronic cardiac dysfunction

• US 9,789,316 B2
• Filed: 08/12/2016
• Issued: 10/17/2017
• Est. Priority Date: 04/25/2014
• Status: Active Grant

• Current Assignee: LivaNova USA, Inc. (LivaNova Plc), East Tennessee State University (University and Community College System Tennessee State)
• Original Assignee: Cyberonics, Inc, East Tennessee State University (University and Community College System Tennessee State)
• Inventors: Libbus, Imad, Amurthur, Badri, KenKnight, Bruce H., Ardell, Jeffrey L.
• Primary Examiner(s): MAHMOOD, NADIA AHMAD
• Application Number:
  US15/236,039
• Publication Number:
  US 20160346549A1
• Time in Patent Office: 431 Days
• Field of Search: 607 60, 607 2, 607 6, 607 9
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/36053 adapted for vagal stimulation A61N1/36114 takes precedence
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/36139 with automatic adjustment
• CPC Class Codes: A61N 1/36146 specified by the stimulation parameters
• CPC Class Codes: A61N 1/36157 Current A61N1/3616 takes precedence
• CPC Class Codes: A61N 1/36171 Frequency
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy

Abstract

Systems and methods are provided for delivering neurostimulation therapies to patients for treating chronic heart failure. A neural fulcrum zone is identified and ongoing neurostimulation therapy is delivered within the neural fulcrum zone. The implanted stimulation device includes a physiological sensor for recording the patient'"'"'s response to the neurostimulation therapy on an ambulatory basis over extended periods of time.

Claims

1. An implantable medical device (IMD), comprising:

an electrode assembly;

a neurostimulator coupled to the electrode assembly, said neurostimulator adapted to deliver a stimulation signal to a patient in a neural fulcrum zone of the patient, said stimulation signal comprising an ON time and an OFF time;

a heart rate sensor configured to acquire a heart rate signal from the patient; and

a control system coupled to the neurostimulator, and the heart rate sensor and configured to;

monitor a baseline signal acquired by the heart rate sensor, wherein the baseline signal comprises a baseline heart rate during the OFF time of the stimulation signal;

monitor a response signal acquired by the heart rate sensor, wherein the response signal comprises a heart rate response during the ON time of the stimulation signal; and

detect whether the stimulation signal is within the neural fulcrum zone corresponding to a stimulation intensity during which a transition heart rate response is detected, the transition heart rate response being between tachycardia and bradycardia and comprising a heart rate change between the baseline signal and the response signal that is less than a predefined threshold.

2. The IMD according to claim 1, wherein the control system is programmed to periodically record the baseline signals and the response signals for a period of at least one week.

3. The IMD according to claim 1, wherein the control system is programmed to periodically record the baseline signals and the response signals for a period of at least one month.

4. The IMD according to claim 1, wherein the control system is programmed to periodically record the baseline signals and the response signals for a period of at least one year.

5. The IMD according to claim 1, further comprising:

a communications interface configured to wirelessly transmit the recorded baseline signals and response signals to an external computing device.

6. The IMD according to claim 1, wherein the control system is further programmed to activate the neurostimulator to chronically deliver stimulation signals to treat chronic cardiac dysfunction.

7. The IMD according to claim 1, wherein:

the control system is programmed to monitor the baseline signal during the OFF time of the stimulation signal after a delay period following the ON time of the stimulation signal.

8. The IMD according to claim 1, wherein:

the control system is programmed to monitor the response signal during the ON time of the stimulation signal after a delay period following initiation of the ON time of the stimulation signal.

9. The IMD according to claim 1, wherein:

the control system is programmed to calculate a baseline signal average of a plurality of OFF time periods of the stimulation signal, and to calculate a response signal average of a plurality of ON time periods of the stimulation signal.

10. The IMD according to claim 1, wherein:

the electrode assembly and the neurostimulator are adapted to deliver the stimulation signal to a vagus nerve of the patient.

11. A method of operating an implantable medical device (IMD) comprising a heart rate sensor configured to acquire a heart rate signal from the patient and a neurostimulator coupled to an electrode assembly and adapted to deliver a stimulation signal to a patient, the method comprising:

activating the neurostimulator to deliver a stimulation signal comprising an ON time and an OFF time;

monitoring a baseline signal acquired by the heart rate sensor, wherein the monitoring the baseline signal comprises monitoring a heart rate response during the OFF time of the stimulation signal;

monitoring a response signal acquired by the heart sensor, wherein the monitoring the response signal comprises monitoring a heart rate response during the ON time of the stimulation signal; and

detecting whether the stimulation signal is within the neural fulcrum zone corresponding to a stimulation intensity during which a transition heart rate response is detected, the transition heart rate response being between tachycardia and bradycardia and comprising a heart rate change between the baseline signal and the response signal that is less than a predefined threshold.

12. The method according to claim 11, further comprising periodically recording the baseline signals and the response signals for a period of at least one week.

13. The method according to claim 11, further comprising periodically recording the baseline signals and the response signals for a period of at least one month.

14. The method according to claim 11, further comprising periodically recording the baseline signals and the response signals for a period of at least one year.

15. The method according to claim 11, further comprising wirelessly transmitting the recorded baseline signals and response signals to an external computing device.

16. The method according to claim 11, wherein the activating the neurostimulator comprises activating the neurostimulator to chronically deliver stimulation signals to treat chronic cardiac dysfunction.

17. The method according to claim 11, wherein monitoring the baseline signal comprises monitoring the baseline signal during the OFF time of the stimulation signal after a delay period following the ON time of the stimulation signal.

18. The method according to claim 11, wherein the monitoring the response signal comprises monitoring the response signal during the ON time of the stimulation signal after a delay period following initiation of the ON time of the stimulation signal.

19. The method according to claim 11, further comprising:

calculating a baseline signal average of a plurality of OFF time periods of the stimulation signal; and

calculating a response signal average of a plurality of ON time periods of the stimulation signal.

20. The method according to claim 11, wherein the activating the neurostimulator comprises activating the neurostimulator to deliver the stimulation signal to a vagus nerve of the patient.