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

• US 9,415,224 B2
• Filed: 04/25/2014
• Issued: 08/16/2016
• 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): Stigell, Theodore
• Assistant Examiner(s): MAHMOOD, NADIA AHMAD
• Application Number:
  US14/262,289
• Publication Number:
  US 20150306395A1
• Time in Patent Office: 844 Days
• Field of Search: 607/2, 607/6, 607/9, 607/62, 607/60
• US Class Current: 1/1
• 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 the patient'"'"'s neural fulcrum zone, 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;

a non-volatile memory;

a control system coupled to the neurostimulator, the physiological sensor, and the non-volatile memory, said control system being programmed to;

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

record in the non-volatile memory the baseline signals and the response signals on an ambulatory basis;

wherein the neural fulcrum zone corresponds to a stimulation intensity during which a transition heart rate response is detected, said transition heart rate response being between tachycardia and bradycardia and comprising a heart rate change of between about 0% and a decrease of about 5%.

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 periods of the stimulation signal after a delay period following the ON time periods 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 periods of the stimulation signal after a delay period following initiation of the ON time periods 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 non-volatile memory, a heart rate sensor configured to acquire a heart rate signal from the patient, and a neurostimulator coupled to an electrode assembly, said neurostimulator adapted to deliver a stimulation signal to a patient, the method comprising:

activating the neurostimulator to deliver a stimulation signal in a patient'"'"'s neural fulcrum zone, said 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 baseline heart rate during the OFF time periods of the stimulation signal;

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

recording in the non-volatile memory the baseline signals and the response signals on an ambulatory basis;

wherein the neural fulcrum zone corresponds to a stimulation intensity during which a transition heart rate response is detected, said transition heart rate response being between tachycardia and bradycardia and comprising a heart rate change of between about 0% and a decrease of about 5%.

12. The method according to claim 11, wherein said recording the baseline signals and the response signals on an ambulatory basis comprises periodically recording the baseline signals and the response signals for a period of at least one week.

13. The method according to claim 11, wherein said recording the baseline signals and the response signals on an ambulatory basis comprises periodically recording the baseline signals and the response signals for a period of at least one month.

14. The method according to claim 11, wherein said recording the baseline signals and the response signals on an ambulatory basis comprises 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:

said activating the neurostimulator comprises activate the neurostimulator to chronically deliver stimulation signals to treat chronic cardiac dysfunction.

17. The method according to claim 11, wherein:

said monitoring the baseline signal comprises monitoring the baseline signal during the OFF time periods of the stimulation signal after a delay period following the ON time periods of the stimulation signal.

18. The method according to claim 11, wherein:

said monitoring the response signal comprises monitoring the response signal during the ON time periods of the stimulation signal after a delay period following initiation of the ON time periods 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:

said activating the neurostimulator comprises activating the neurostimulator to deliver the stimulation signal to a vagus nerve of the patient.