ACTIVE IMPLANTABLE MEDICAL DEVICE FOR HEART FAILURE THERAPY WITH STOCHASTIC STIMULATION OF THE VAGUS NERVE

• US 20140364921A1
• Filed: 06/10/2014
• Published: 12/11/2014
• Est. Priority Date: 06/11/2013
• Status: Active Grant

• Current Assignee: Sorin CRM SAS (MicroPort Scientific Corp.)
• Original Assignee: Sorin CRM SAS (MicroPort Scientific Corp.)
• Inventors: LEGAY, Thierry, BLUMSTEIN, Herv
• Granted Patent: US 9,566,437 B2
• Time in Patent Office: Days
• US Class Current: 607/62
• 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 1/36135 using physiological parameters
• CPC Class Codes: A61N 1/36139 with automatic adjustment

Abstract

A method for heart treatment includes analyzing the cardiac rhythm. The method further includes utilizing a generator to produce discharges (S_i) of N pulses (I) of VNS stimulation in succession. The discharge may be synchronized to a detected R ventricular depolarization wave of each cardiac cycle. The method further includes controlling a stochastic modulation of the discharges control of the delivery of each VNS pulse of each discharge by selective inhibition or not of the generation of these VNS pulses. The number of pulses of each discharge thus randomly varies, and thus varies the VNS stimulation energy of this discharge, which is artificially induced, cycle-to-cycle variability in the RR interval. This stochastic therapy is applied if the spontaneous heart rate variability falls below a minimum level.

Claims

1. An active implantable medical device for the treatment of heart failure with vagus nerve stimulation (VNS), synchronous with cardiac activity, including:

a circuit configured to analyze the cardiac rhythm by collecting an intracardiac electrogram EGM signal and detecting a ventricular depolarization R-wave in each cardiac cycle; and

a generator, adapted to produce discharges, each discharge comprising N pulses of VNS stimulation generable in succession, with NO, the generator configured to initiate the production of each possible discharge VNS with an R-wave synchronization of the moment of delivery of the first VNS pulse of this discharge,

wherein the generator comprises a stochastic modulation module configured to separately controlling the delivery of each of the N possible VNS pulses of each discharge according to the result of a randomization;

wherein the circuit for analyzing the cardiac rhythm is further configured to evaluate a spontaneous heart rate variability parameter (VSS) and wherein the stochastic modulation is activated in response to the spontaneous heart rate variability parameter falling below a threshold.

2. The device of claim 1, wherein the randomization varies the number of VNS pulses delivered in a discharge, varies the energy contained in VNS stimulation of this discharge, and wherein the randomization artificially induces a cycle-to-cycle variability of the RR interval.

3. The device of claim 1, wherein said parameter of spontaneous heart rate variability (VSS) of the heart rate is a measure of the variability of the RR interval.

4. The device of claim 3, wherein said measure of the variability of the RR interval is a measure of the group of:

the standard deviation over a given recording period, of the RR intervals;

the standard deviation over a given recording period, of the average of the RR intervals on temporal segments of predetermined duration; and

the root mean square of the variations in duration between consecutive RR intervals.

5. The device of claim 1, wherein the amplitudes of VNS pulses delivered by the generator are all equal.

6. The device of claim 1, wherein the widths of the VNS pulses delivered by the generator are all equal.

7. The device of claim 1, wherein the time intervals between the possible instants of application of two successive VNS pulses delivered by the generator at each discharge are all equal, whether delivery by the generator is inhibited or not by the stochastic modulation.

8. The device of claim 1, wherein the number N of pulses VNS delivered by the generator for each discharge is between 1 and 5.

9. A method for heart health treatment, comprising:

producing vagal nerve stimulation (VNS) discharges comprising of a plurality of pulses of VNS stimulation generable in succession;

applying stochastic modulation to the controlled delivery of each VNS discharge by selectively inhibiting the generation of these VNS pulses, wherein the stochastic modulation comprises a randomization, wherein the stochastic modulation is provided when the spontaneous heart rate variability is below a predetermined level.

10. The method of claim 9, wherein each discharge is synchronized to a detected R ventricular depolarization wave of each cardiac cycle;

11. The method of claim 9, wherein the randomization varies the number of VNS pulses delivered in a discharge, varies the energy contained in VNS stimulation of this discharge, and wherein the randomization artificially induces a cycle-to-cycle variability of the RR interval.

12. The method of claim 9, wherein said parameter of spontaneous heart rate variability (VSS) of the heart rate is a measure of the variability of the RR interval.

13. The method of claim 12, wherein said measure of the variability of the RR interval is a measure of the group of:

the standard deviation over a given recording period, of the RR intervals;

the standard deviation over a given recording period, of the average of the RR intervals on temporal segments of predetermined duration; and

the root mean square of the variations in duration between consecutive RR intervals.

14. The method of claim 9, wherein the amplitudes of VNS pulses delivered by the generator are all equal.

15. The method of claim 14, wherein the widths of the VNS pulses delivered by the generator are all equal.

16. The method of claim 15, wherein the time intervals between the possible instants of application of two successive VNS pulses delivered by the generator at each discharge are all equal, whereby whether delivery by the generator is inhibited or not is controlled by the stochastic modulation.

17. The method of claim 9, wherein the number N of pulses VNS delivered by the generator for each discharge is between 1 and 5.

18. A device for controlling heart health treatment, comprising:

a vagus nerve stimulation (VNS) lead and electrode;

a control device coupled to the VNS lead and electrode, wherein the control device stochastically modulates a series of pulses of each VNS discharge burst, wherein the control device activates the stochastic modulation when the control device determines that a spontaneous heart rate variability is below a predetermined threshold.

19. The device of claim 18, wherein the VNS discharge bursts are synchronized to a detected R ventricular polarization wave of the cardiac cycle.

20. The device of claim 18, wherein the VNS pulses of the VNS discharge burst are constant in amplitude, duration, and spacing between potential pulses, wherein the variability is provided by the stochastic modulation.