Nerve signal differentiation in cardiac therapy

• US 8,620,425 B2
• Filed: 07/30/2010
• Issued: 12/31/2013
• Est. Priority Date: 04/29/2010
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Zhou, Xiaohong, Burnes, John Edward, Kornet, Lilian, Cornelussen, Richard N. M.
• Primary Examiner(s): Bertram, Eric D.
• Application Number:
  US12/848,010
• Publication Number:
  US 20120029600A1
• Time in Patent Office: 1,250 Days
• Field of Search: 607/9
• US Class Current: 607/9
• CPC Class Codes: A61B 5/388 Nerve conduction study, e.g. detecting action potential of peripheral nerves
• 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 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/3686 configured for selecting the electrode configuration on a lead A61N1/3688 takes precedence
• CPC Class Codes: A61N 1/39622 Pacing therapy

Abstract

Methods of nerve signal differentiation, methods of delivering therapy using such nerve signal differentiation, and to systems and devices for performing such methods. Nerve signal differentiation may include locating two electrodes proximate nerve tissue and differentiating between efferent and afferent components of nerve signals monitored using the two electrodes.

Claims

1. A device for delivering therapy comprising:

monitoring apparatus configured to monitor physiological parameters of a patient, wherein the monitoring apparatus comprises at least two electrodes configured to monitor electrical activity of at least one nerve fiber of the patient, wherein the at least one nerve fiber extends from a central end to a peripheral end, wherein the at least two electrodes comprise a first electrode and a second electrode, wherein the first electrode is configured to be located closer to the central end of the at least one nerve fiber of the patient than the second electrode;

a sensing module operably coupled to the monitoring apparatus and configured to receive the monitored physiological parameters;

a therapy delivery module configured to deliver electrical stimulation to the at least one nerve fiber of the patient; and

a control module operably coupled to the sensing module and to the therapy delivery module and configured to;

differentiate between efferent activity and afferent activity of the monitored electrical activity of the at least one nerve fiber based on a direction of the monitored electrical activity of the at least one nerve fiber resulting in data representative thereof, wherein the control module is configured to determine the direction of the monitored electrical activity of the at least one nerve fiber based on at least one of polarity, timing, frequency, and velocity of the monitored electrical activity as monitored by the first electrode and the second electrode; and

initiate or adjust delivery of electrical stimulation to the at least one nerve fiber based on the data resulting from the differentiation;

determine whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced over time based on the monitored electrical activity of the at least one nerve fiber, and

initiate or adjust the delivery of electrical stimulation to the at least one nerve fiber based on the data resulting from the differentiation by initiating or adjusting the delivery of electrical stimulation to the at least one nerve fiber if the efferent activity is reduced,

wherein the control module is further configured to determine whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced by comparing the efferent activity of the electrical activity of the at least one nerve fiber to the afferent activity of the electrical activity of the at least one nerve fiber.

4. The device of any one of claims 1 to 3, wherein the control module is further configured to determine whether the efferent activity of the monitored electrical activity of the at least one nerve fiber is reduced by comparing the pulses per second of the efferent activity to a selected value.

5. The device of any one of claims 1 to 3, wherein the control module is further configured to determine whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced by comparing the pulses per second of presently-monitored efferent activity to the pulses per second of previously-monitored efferent activity.

6. A method of delivering therapy using a device of any one of claims 1 to 3, wherein the method comprises:

monitoring physiological parameters of a patient, wherein the physiological parameters comprise electrical activity of at least one nerve fiber of a patient;

differentiating between efferent activity and afferent activity of the monitored electrical activity of the at least one nerve fiber resulting in data representative thereof; and

initiating or adjusting delivery of electrical stimulation to the at least one nerve fiber based on the data resulting from the differentiation.

7. The method of claim 6, wherein the method further comprises determining whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced over time based on the monitored electrical activity of the at least one nerve fiber, and wherein initiating or adjusting delivery of electrical stimulation to the at least one nerve fiber based on the data resulting from the differentiation comprises initiating or adjusting the delivery of electrical stimulation to the at least one nerve fiber if the efferent activity of the monitored electrical activity of the at least one nerve fiber is reduced.

8. The method of claim 6, wherein determining whether the efferent activity of the monitored electrical activity of the at least one nerve fiber is reduced comprises comparing the pulses per second of the efferent activity to a selected value.

9. The method of claim 6, wherein determining whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced comprises comparing the pulses per second of presently-monitored efferent activity to the pulses per second of previously-monitored efferent activity.

10. The method of claim 6, wherein determining whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced comprises comparing the efferent activity of the electrical activity of the at least one nerve fiber to the afferent activity of the electrical activity of the at least one nerve fiber.

11. The method of claim 6, wherein determining whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced comprises comparing the average amplitude of a selected frequency range of the efferent activity to a selected value.

12. The method of claim 6, wherein determining whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced comprises comparing the average power of a selected frequency range of the efferent activity to a selected value.

2. A device for delivering therapy comprising:

monitoring apparatus configured to monitor physiological parameters of a patient, wherein the monitoring apparatus comprises at least two electrodes configured to monitor electrical activity of at least one nerve fiber of the patient, wherein the at least one nerve fiber extends from a central end to a peripheral end, wherein the at least two electrodes comprise a first electrode and a second electrode, wherein the first electrode is configured to be located closer to the central end of the at least one nerve fiber of the patient than the second electrode;

a sensing module operably coupled to the monitoring apparatus and configured to receive the monitored physiological parameters;

a therapy delivery module configured to deliver electrical stimulation to the at least one nerve fiber of the patient; and

a control module operably coupled to the sensing module and to the therapy delivery module and configured to;

differentiate between efferent activity and afferent activity of the monitored electrical activity of the at least one nerve fiber based on a direction of the monitored electrical activity of the at least one nerve fiber resulting in data representative thereof, wherein the control module is configured to determine the direction of the monitored electrical activity of the at least one nerve fiber based on at least one of polarity, timing, frequency, and velocity of the monitored electrical activity as monitored by the first electrode and the second electrode; and

initiate or adjust delivery of electrical stimulation to the at least one nerve fiber based on the data resulting from the differentiation;

determine whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced over time based on the monitored electrical activity of the at least one nerve fiber, and

initiate or adjust the delivery of electrical stimulation to the at least one nerve fiber based on the data resulting from the differentiation by initiating or adjusting the delivery of electrical stimulation to the at least one nerve fiber if the efferent activity is reduced,

wherein the control module is configured to determine whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced by at least comparing the average amplitude of a selected frequency range of the efferent activity to a selected value.

3. A device for delivering therapy comprising:

monitoring apparatus configured to monitor physiological parameters of a patient, wherein the monitoring apparatus comprises at least two electrodes configured to monitor electrical activity of at least one nerve fiber of the patient, wherein the at least one nerve fiber extends from a central end to a peripheral end, wherein the at least two electrodes comprise a first electrode and a second electrode, wherein the first electrode is configured to be located closer to the central end of the at least one nerve fiber of the patient than the second electrode;

a sensing module operably coupled to the monitoring apparatus and configured to receive the monitored physiological parameters;

a therapy delivery module configured to deliver electrical stimulation to the at least one nerve fiber of the patient; and

a control module operably coupled to the sensing module and to the therapy delivery module and configured to;

differentiate between efferent activity and afferent activity of the monitored electrical activity of the at least one nerve fiber based on a direction of the monitored electrical activity of the at least one nerve fiber resulting in data representative thereof, wherein the control module is configured to determine the direction of the monitored electrical activity of the at least one nerve fiber based on at least one of polarity, timing, frequency, and velocity of the monitored electrical activity as monitored by the first electrode and the second electrode; and

initiate or adjust delivery of electrical stimulation to the at least one nerve fiber based on the data resulting from the differentiation;

determine whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced over time based on the monitored electrical activity of the at least one nerve fiber, and

initiate or adjust the delivery of electrical stimulation to the at least one nerve fiber based on the data resulting from the differentiation by initiating or adjusting the delivery of electrical stimulation to the at least one nerve fiber if the efferent activity is reduced,

wherein the control module is configured to determine whether the efferent activity of the electrical activity of the at least one nerve fiber is reduced by at least comparing the average power of a selected frequency range of the efferent activity to a selected value.