Systems, devices and methods used in verifying neural stimulation capture

• US 8,447,397 B2
• Filed: 05/01/2012
• Issued: 05/21/2013
• Est. Priority Date: 04/10/2006
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Libbus, Imad, Kramer, Andrew P.
• Primary Examiner(s): Manuel, George
• Assistant Examiner(s): Wieland, Robert N
• Application Number:
  US13/460,949
• Publication Number:
  US 20120215276A1
• Time in Patent Office: 385 Days
• Field of Search: 607/4, 607/2, 607/17, 607/25, 607/45, 600/509, 600/510
• US Class Current: 607/4
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/36117 for treating hypertension

Abstract

Various system embodiments comprise a neural stimulator, a premature ventricular contraction (PVC) event detector, a heart rate detector, an analyzer, and a controller. The neural stimulator is adapted to generate a stimulation signal adapted to stimulate an autonomic neural target. The analyzer is adapted to, in response to a PVC event signal from the PVC event detector, generate an autonomic balance indicator (ABI) as a function of pre-PVC heart rate data and post-PVC heart rate data. Other aspects and embodiments are provided herein.

Claims

1. A method, comprising:

using an implantable device to;

deliver neural stimulation to a neural stimulation site,

detect heart rate,

perform a plurality of heart rate turbulence (HRT) measurements at a plurality of discrete times using the detected heart rate to identify a plurality of HRT measurement values;

record the plurality of HRT measurement values in a memory of the implantable device, and

record in the memory a time corresponding to each of the measurement values; and

verifying neural stimulation capture using the recorded HRT measurement values and times.

2. The method of claim 1, wherein the neural stimulation site can adapt to neural stimulation, and wherein verifying neural stimulation capture includes identifying changes in a threshold for neural stimulation capture attributed to neural stimulation adaptation.

3. The method of claim 1, further comprising reporting data useful for verifying neural stimulation capture from the implantable device to an external device.

4. The method of claim 3, wherein verifying neural stimulation capture includes using the external device to verify neural stimulation capture.

5. The method of claim 3, further comprising monitoring heart failure using the data reported to the external device.

6. The method of claim 3, further comprising monitoring therapy effectiveness using the data reported to the external device.

7. The method of claim 1, wherein using the implantable device to deliver neural stimulation includes intermittently delivering neural stimulation using the implantable device to control neural stimulation ON timing and stimulation OFF timing.

8. The method of claim 1, further comprising trending the HRT measurement values.

9. The method of claim 1, further comprising averaging the HRT measurement values.

10. The method of claim 1, further comprising using the implantable device to record detected heart rate in a first-in first-out (FIFO) buffer, to sense a premature ventricular contraction (PVC), and to respond to the sensed PVC to measure HRT using the detected heart rate data in the FIFO buffer.

11. The method of claim 1, further comprising using the implantable device to record detected heart rate in a first-in first-out (FIFO) buffer, to deliver a ventricular pace to induce a premature ventricular contraction (PVC), and to measure HRT when the PVC is induced using the detected heart rate data in the FIFO buffer.

12. The method of claim 1, further comprising using a preprogrammed schedule in the implantable device to control timing of the plurality of HRT measurements at the plurality of discrete times.

13. The method of claim 1, further comprising triggering HRT measurements based on sensor data, or therapy changes, or an external signal.

14. A neural stimulation system for stimulating a neural stimulation site that can adapt to neural stimulation, the system comprising:

a neural stimulator configured to stimulate the neural stimulation site;

a memory;

a heart rate detector configured to detect heart rate;

an analyzer operably connected to the heart rate detector, wherein the analyzer is configured to measure heart rate turbulence (HRT);

a clock; and

a controller operably connected to the neural stimulator, the analyzer and the clock, wherein the controller is configured to;

control the neural stimulator to control the stimulation of the neural stimulation site, wherein the controller is configured to control neural stimulation ON timing and neural stimulation OFF timing; and

perform a process useful for verifying neural stimulation capture of the neural stimulation site that can adapt to neural stimulation, wherein in performing the process, the controller is configured to;

control the analyzer to perform a plurality of HRT measurements at a plurality of discrete times during a neural stimulation ON period of time and during a neural stimulation OFF period of time;

record measurement values for the plurality of HRT measurements taken at the discrete times during the neural stimulation ON period of time and during the neural stimulation OFF period of time in the memory; and

record a time, corresponding to each of the measurement values, in the memory.

15. The system of claim 14, wherein the controller is configured to perform a calculation using the plurality of HRT measurements.

16. The system of claim 14, further comprising a logic circuit configured to trigger an HRT measurement in response to an event trigger, wherein the device is configured to provide the event trigger based on sensor data, based on therapy changes, or based on an external signal.

17. An implantable medical device for stimulating a neural stimulation site that can adapt to neural stimulation, the device comprising:

a neural stimulator configured to stimulate the neural stimulation site;

a memory;

a heart rate detector configured to detect heart rate;

an analyzer operably connected to the heart rate detector, wherein the analyzer is configured to measure heart rate turbulence (HRT);

a transceiver;

a clock; and

a controller operably connected to the neural stimulator, the analyzer, the transceiver and the clock, wherein the controller is configured to control neural stimulation ON timing and neural stimulation OFF timing, wherein the controller is configured to;

control the neural stimulator to control the stimulation of the neural stimulation site; and

perform a process useful for verifying neural stimulation capture, wherein in performing the process, the controller is configured to;

control the analyzer to perform a plurality of HRT measurements at a plurality of discrete times during a neural stimulation ON period of time and during a neural stimulation OFF period of time;

record measurement values for the plurality of HRT measurements taken at the discrete times during the neural stimulation ON period of time and during the neural stimulation OFF period of time in the memory; and

record a time, corresponding to each of the measurement values, in the memory; and

use the transceiver to transmit from the implantable medical device to an external device data useful for verifying neural stimulation capture.

18. The device of claim 17, wherein the controller is configured to control the analyzer to measure HRT at relatively constant time intervals.

19. The device of claim 17, wherein the controller is configured to control the analyzer to intermittently measure HRT at non-equal time intervals.

20. The device of claim 17, wherein the controller is configured to control the analyzer to measure HRT at pre-programmed time intervals.

21. The device of claim 17, wherein the analyzer is configured to use detected heart rate before a premature ventricular contraction (PVC) and detected heart rate after the PVC to measure HRT, record detected heart rate data in a first-in first-out (FIFO) buffer, and sense the PVC, wherein the analyzer is configured to use the detected heart rate data in the FIFO buffer as the detected heart rate before the PVC.

22. The device of claim 17, wherein the analyzer is configured to use detected heart rate before a premature ventricular contraction (PVC) and detected heart rate after the PVC to measure HRT, further comprising a PVC stimulator configured to deliver a ventricular pace to induce the PVC, wherein the analyzer is configured to record detected heart rate data in a first-in first-out (FIFO) buffer, and wherein the controller is configured to control the PVC stimulator to induce the PVC.

23. The device of claim 17, wherein the controller is configured to use the recorded measurement values to adjust the stimulation of the neural stimulation site.

24. A neural stimulation system for stimulating a neural stimulation site that can adapt to neural stimulation, the system comprising:

a neural stimulator configured to stimulate the neural stimulation site;

a memory;

a heart rate detector configured to detect heart rate;

an analyzer operably connected to the heart rate detector, wherein the analyzer is configured to measure heart rate turbulence (HRT);

a clock configured to monitor time; and

a controller operably connected to the neural stimulator, the analyzer and the clock, the controller configured to;

control the neural stimulator to control the stimulation of the neural stimulation site;

perform a process useful for verifying neural stimulation capture of the neural stimulation site that can adapt to neural stimulation, wherein in performing the process, the controller is configured to;

control the analyzer to perform a plurality of HRT measurements over a period of time;

record measurement values for the plurality of HRT measurements in the memory of the implantable medical device;

record a time with each of the measurement values in the memory of the implantable medical device; and

identify changes in a threshold for neural stimulation capture attributed to neural stimulation adaptation.

25. The system of claim 24, further comprising a logic circuit configured to trigger the process useful for verifying neural stimulation capture in response to an event trigger, wherein the device is configured to provide the event trigger based on sensor data, based on therapy changes, or based on an external signal.