Temporal configuration of a motion sensor in an implantable medical device

• US 10,709,892 B2
• Filed: 03/26/2018
• Issued: 07/14/2020
• Est. Priority Date: 08/27/2015
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Kane, Michael J., Linder, William J., Haasl, Benjamin J., Huelskamp, Paul, Maile, Keith R., Balczewski, Ron A., Mi, Bin, Hatlestad, John D., Shuros, Allan Charles
• Primary Examiner(s): Gedeon, Brian T
• Application Number:
  US15/935,806
• Publication Number:
  US 20180207426A1
• Time in Patent Office: 841 Days
• Field of Search: None
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1107 Measuring contraction of parts of the body, e.g. organ, muscle apparatus for measuring work or force in general G01L
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/6869 Heart
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: A61N 1/36578 controlled by mechanical motion of the heart wall, e.g. measured by an accelerometer or microphone
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/371 Capture, i.e. successful stimulation
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

Methods and devices for configuring the use of a motion sensor in an implantable cardiac device. The electrical signals of the patient'"'"'s heart are observed and may be correlated to the physical motion of the heart as detected by the motion sensor of the implantable cardiac device in order to facilitate temporal configuration of motion sensor data collection that avoids detecting cardiac motion in favor of overall motion of the patient.

Claims

1. A method of operating an implantable device (ID) adapted for disposition within the heart of a patient, the ID comprising a motion sensor for detecting movement of the patient, the method comprising:

initializing the ID by;

contemporaneously collecting a set of data points from the motion sensor and from a cardiac electrical signal;

correlating time periods within the set of data points from the motion sensor to cardiac activity reflected by the cardiac electrical signal; and

configuring the ID to capture data from the motion sensor by reference to specific repeatable elements of the cardiac electrical signal;

using the ID as configured in the initializing step to capture cardiac signals of the patient and motion signals for the patient.

2. The method of claim 1 further comprising;

using the motion signals to determine an activity level of the patient; and

setting and implementing a pacing rate for the patient using the determined activity level.

3. The method of claim 1 wherein the step of configuring the ID to capture data from the motion sensor is performed by:

determining when intrinsic mechanical motion of the heart is detected by the motion sensor relative to electrical signals of the heart; and

setting a data capture period for the motion sensor relative to a specified electrical signal of the heart to avoid capturing the intrinsic mechanical motion of the heart with the motion sensor.

4. The method of claim 1 wherein the step of configuring the ID to capture data from the motion sensor is performed by:

determining when a quiet period in the intrinsic mechanical motion of the heart is detected by the motion sensor relative to electrical signals of the heart; and

setting a data capture period for the motion sensor relative to a specified electrical signal of the heart to avoid capturing the intrinsic mechanical motion of the heart with the motion sensor.

5. The method of claim 1 wherein the step of configuring the ID to capture data from the motion sensor includes determining a delay after a T-wave in the cardiac electrical signal.

6. The method of claim 5 wherein the delay is configured as a function of cardiac rate.

7. The method of claim 6 wherein the cardiac rate is determined as a rate of pacing output of the ID.

8. The method of claim 6 wherein the cardiac rate is determined as an intrinsic rate of the patient'"'"'s heart.

9. The method of claim 1 wherein the specific repeatable elements of the cardiac electrical signal are one of an R-wave or a QRS complex.

10. The method of claim 1 wherein the specific repeatable elements of the cardiac electrical signal comprise the T-wave.

11. The method of claim 1 wherein the step of configuring the ID to capture data from the motion sensor by reference to specific repeatable elements of the cardiac electrical signal further includes configuring the ID to maintain the motion sensor in a low power state except when the ID is capturing data therefrom.

12. An implantable medical device (IMD) adapted for implantation within the heart of a patient and comprising:

a plurality of electrodes adapted for one or more of sensing electrical cardiac activity and delivering therapy;

a motion sensor for detecting movement of the patient; and

a processing module configured to receive signals from the motion sensor and from the plurality of electrodes to determine patient status, wherein the processing module is configured to enhance the operation of the device by;

initializing the IMD by;

contemporaneously collecting a set of data points from the motion sensor and from a cardiac electrical signal capturing using two or more of the plurality of electrodes;

correlating time periods within the set of data points from the motion sensor to cardiac activity reflected by the cardiac electrical signal; and

setting up the IMD to capture data from the motion sensor by reference to specific repeatable elements of the cardiac electrical signal; and

using the IMD as set up in the initializing step to capture cardiac signals of the patient and motion signals for the patient.

13. An IMD as in claim 12 wherein the processing module is further configured to:

use the motion signals to determine an activity level of the patient; and

set and implement a pacing rate for the patient using the determined activity level.

14. An IMD as in claim 12 wherein the processing module is configured to set up the IMD to capture data from the motion sensor by:

determining when intrinsic mechanical motion of the heart is detected by the motion sensor relative to electrical signals of the heart; and

setting a data capture period for the motion sensor relative to a specified electrical signal of the heart to avoid capturing intrinsic mechanical motion of the heart with the motion sensor.

15. An IMD as in claim 12 wherein the processing module is configured to set up the IMD to capture data from the motion sensor by:

determining when a quiet period in the intrinsic mechanical motion of the heart is detected by the motion sensor relative to electrical signals of the heart; and

setting a data capture period for the motion sensor relative to a specified electrical signal of the heart to avoid capturing intrinsic mechanical motion of the heart with the motion sensor.

16. An IMD as in claim 12 wherein the processing module is configured to set up the IMD to capture data from the motion sensor by determining a delay after a T-wave in the cardiac electrical signal.

17. An IMD as in claim 16 wherein the processing module is configured to set the delay after a T-wave as a function of cardiac rate.

18. An IMD as in claim 12 wherein the specific repeatable elements of the cardiac electrical signal are one of an R-wave or a QRS complex.

19. An IMD as in claim 12 wherein the specific repeatable elements of the cardiac electrical signal comprise the T-wave.