METHODS AND APPARATUS FOR IMPROVED IPG RATE RESPONSE USING SUBCUTANEOUS ELECTRODES DIRECTLY COUPLED TO AN IMPLANTABLE MEDICAL DEVICE (IMD)

• US 20080228234A1
• Filed: 03/16/2007
• Published: 09/18/2008
• Est. Priority Date: 03/16/2007
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Stancer, Christopher C.
• Granted Patent: US 9,381,366 B2
• Time in Patent Office: Days
• US Class Current: 607/4
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61N 1/0504 Subcutaneous electrodes
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/37518 Anchoring of the implants, e.g. fixation
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

Per the disclosure subcutaneously implantable medical devices (IMDs) with rate responsive implantable pulse generator (IPG) capability that also include dual patient activity sensors are adaptively controlled. One of the activity sensors uses multiple electrodes adapted to acquire electrocardiographic signals and signals from non-cardiac muscle tissue (myopotentially-based signals). The signals from the electrode-based activity sensor are used to confirm and/or override the patient-activity sensor signals from the other non-myopotentially-based patient activity sensor. The electrodes are directly mechanically coupled to the housing of the IMD and electrically coupled to circuitry that filters, processes, and interprets both the patient activity sensor signals.

Claims

1. A subcutaneous cardiac activity sensing device, comprising:

an insulative member mechanically coupled to a subcutaneously implantable medical device (IMD);

a patient activity sensor disposed within the IMD providing a patient activity output signal;

a pair of spaced apart electrodes mechanically coupled to the IMD and adapted to sense both electrocardiographic signals and myopotential signals;

circuit means for receiving, processing, and filtering the patient activity output signal, the electrocardiographic signals and the myopotential signals and providing both a non-myopotential-based patient activity signal and an a myopotential-based patient activity signal therefrom; and

wherein the myopotential-based patient activity signal and the non-myopotential-based patient activity signal are logically combined and utilized to control a rate responsive cardiac pulse stimulator.

2. A device according to claim 1, wherein said patient activity sensor comprises one of a single axis accelerometer and a multi-axis accelerometer.

3. A device according to claim 1, patient activity sensor comprises a piezoelectrically-based motion sensor.

4. A device according to claim 1, wherein the pair of spaced apart electrodes include opposing major planar surfaces and the major planar surfaces mimic a curved portion of the IMD.

5. A device according to claim 1, wherein the insulative member comprises a resilient shroud member coupled around at least a portion of the periphery of the IMD.

6. A device according to claim 5, further comprising a plurality of ports formed between an interior surface portion and an exterior surface portion of the resilicent shroud member.

7. A device according to claim 6, further comprising medical grade adhesive disposed around between the at least a part of the periphery of the IMD.

8. A device according to claim 1, further comprising at least one additional electrode mechanically coupled to the IMD and adapted to sense both electrocardiographic signals and myopotential signals.

9. A device according to claim 8, further comprising a connector module substantially hermetically coupled to the IMD and wherein the at least one additional electrode couples to the connector module.

10. A shroud according to claim 9, further comprising a metallic bonding member coupled to the header portion and to a portion of the IMD.

11. A device according to claim 10, further comprising at least three spaced apart lead-coupling bores formed in the header portion.

12. A device according to claim 11, further comprising a pair of spaced apart conductors disposed within each of the at least three bores.

13. A device according to claim 9, further comprising a suture-receiving aperture formed through the connector module.

14. A device according to claim 1, wherein the pair of electrodes are fabricated from one of a titanium material and a platinum material.

15. A device according to claim 14, wherein the pair of electrodes further includes a coating on at least a major surface thereof.

16. A device according to claim 15, wherein the coating comprises one of a nitride coating, a carbon black coating, a time-release coating.

17. A device according to claim 1, wherein the IMD comprises one of an implantable cardiac IPG and an implantable cardioverter-defibrillator.

18. A method of controlling a rate responsive cardiac pacing scheme, comprising:

receiving a non-myopotentially-based patient activity sensor signal from a sensor coupled to an implantable medical device (IMD);

receiving a myopotential-based patient activity sensor signal from at least a pair of surface electrodes mechanically coupled to a portion of the IMD; and

logically combining the non-myopotentially-based patient activity sensor signal and the myopotentially-based patient activity signal to control a rate responsive cardiac pacing scheme of the IMD.

19. A method according to claim 18, wherein the IMD comprises one of an implantable cardiac pacemaker and an implantable cardioverter-defibrillator.

20. A method according to claim 18, further comprising filtering the non-myopotentially-based patient activity sensor signal and the myopotentially-based patient activity signal prior to logically combining the non-myopotentially-based patient activity sensor signal and the myopotentially-based patient activity signal.