LEADLESS IMPLANTABLE MEDICAL DEVICE WITH DUAL CHAMBER SENSING FUNCTIONALITY

• US 20130123872A1
• Filed: 11/05/2012
• Published: 05/16/2013
• Est. Priority Date: 11/03/2011
• Status: Abandoned Application

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Bornzin, Gene A., Poore, John W.
• Application Number:
  US13/669,168
• Publication Number:
  US 20130123872A1
• Time in Patent Office: Days
• US Class Current: 607/17
• CPC Class Codes: A61N 1/36592 controlled by the heart rate variability
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation
• CPC Class Codes: A61N 1/37 Monitoring; Protecting
• 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

A leadless implantable medical device (LIMD) is provided with dual chamber sensing functionality, without leads, despite the fact that the entire device is located in one chamber. In one embodiment, the LIMD senses local activity in the right atrium (RA) and local activity in the right ventricle (RV), even though it is entirely located in the RA. The sensing electrodes enable sensing in different chambers of the heart while reducing cross talk interference and thus provide accurate tracking of myocardial contraction in multiple chambers.

Claims

1. A leadless implantable medical device (LIMD), comprising:

a housing configured to be implanted entirely within a single local chamber of the heart, the local chamber having local wall tissue that constitutes part of a conduction network of the local chamber;

a controller within the housing to cause stimulus pulses to be delivered;

a sensing circuit to perform sensing;

an active fixation member coupled to the housing, the active fixation member configured to be secured to a septum that separates the local chamber from an adjacent chamber, the adjacent chamber having distal wall tissue, with respect to the local chamber, that constitutes part of a conduction network of the adjacent chamber; and

an electrode pair having first and second active electrode areas coupled to the sensing circuit, the first and second electrode areas positioned such that, when the LIMD is implanted, the electrode pair is electrically coupled to the conduction network of the adjacent chamber, the sensing circuit detecting, as near field signals, voltages originating within the conduction network of the adjacent chamber and sensed by the first and second active electrode areas, the sensing circuit rejecting, as far field signals, voltages originating within the conduction network of the local chamber and sensed by the first and second active electrode areas.

2. The LIMD of claim 1, wherein the sensing circuit and electrode pair are coupled to operate in a bipolar sensing configuration such that the sensing circuit measures a voltage potential difference between the first and second active electrode areas.

3. The LIMD of claim 1, wherein the active fixation member is helical in shape, the first and second active electrode areas being located on separate turns of the active fixation member and at a common distance from the base.

4. The LIMD of claim 1, wherein the electrode pair are provided on the active fixation member within a distal segment thereof, such that when the active fixation member is installed, the electrode pair are located at or near a surface of the distal wall tissue.

5. The LIMD of claim 1, further comprising a pin that extends from the base of the housing, the pin having a distal end with the active electrode areas provided at the distal end of the pin.

6. The LIMD of claim 1, further comprising a second electrode pair having third and fourth active electrode areas that are provided on the base of the housing, the third and fourth active electrode areas coupled to the sensing circuit and positioned such that the second electrode pair is electrically coupled to the conduction network of the local chamber, the sensing circuit detecting, as near field signals, voltages originating within the conduction network of the local chamber and sensed by the third and fourth active electrode areas, the sensing circuit rejecting, as far field signals, voltages originating within the conduction network of the adjacent chamber and sensed by the third and fourth active electrode areas.

7. The LIMD of claim 1, wherein the active fixation member includes a proximal segment configured to be located at a local sensing site, the LIMD further comprising a second electrode pair provided on the active fixation member in the proximal segment to be electrically coupled to the conduction network of the local chamber, the sensing circuit detecting, as near field signals, voltages originating within the conduction network of the local chamber, the sensing circuit rejecting, as far field signals, voltages originating within the conduction network of the adjacent chamber.

8. The LIMD of claim 1, wherein the active fixation member includes first and second electrode pairs that are located within proximal and distal segments of the active fixation member, respectively, the electrodes in the proximal segment being positioned to be electrically coupled to the conduction network of the local chamber.

9. The LIMD of claim 1, wherein the first and second electrodes are separated by an inter-electrode spacing such that as depolarization occurs along the distal wall tissue and near field electrical activity moves across the first and second electrodes, an associated voltage potential is created between the first and second electrodes, the voltage potential being detected by the sensing circuit as a near field signal.

10. The LIMD of claim 1, wherein the first and second electrodes are separated by an inter-electrode spacing such that as far field electrical activity traverses the first and second electrodes, a common mode signal is experienced between the first and second electrodes, the common mode signal being rejected by the sensing circuit.

11. A method for implanting a leadless implantable medical device (LIMD) the LIMD having a housing that includes a sensing circuit to perform sensing and an electrode pair having first and second active electrode areas coupled to the sensing circuit, the method comprising:

guiding the LIMD, utilizing an introducer, to an activation site that is located entirely within a single local chamber of the heart and proximate to tissue of interest, the local chamber having local wall tissue that constitutes part of a conduction network of the local chamber, an adjacent chamber having distal wall tissue, with respect to the local chamber, that constitutes part of a conduction network of the adjacent chamber; and

actively securing the LIMD to the tissue of interest;

positioning the electrode pair to engage wall tissue at a distal activation site within the conduction network of the adjacent chamber;

configuring the sensing circuit to detect, as near field signals, voltages originating within the conduction network of the adjacent chamber and sensed by the first and second active electrode areas; and

configuring the sensing circuit to reject, as far field signals, voltages originating within the conduction network of the local chamber and sensed by the first and second active electrode areas.

12. The method of claim 11, further comprising;

positioning at least a third electrode to engage wall tissue at a local activation site within the conduction network of the local chamber; and

configuring a controller within the housing to cause stimulus pulses to be delivered, in a synchronous manner, through the electrode pair and the third electrode to the distal and local activation sites, respectively, such that stimulus pulses delivered at the distal activation site are timed to cause contraction of the adjacent chamber in a predetermined relation to contraction of the local chamber.

13. The method of claim 11, further comprising configuring the sensing circuit and electrode pair to operate in a bipolar sensing configuration such that the sensing circuit measures a voltage potential difference between the first and second active electrode areas.

14. The method of claim 11, wherein the actively securing operation includes screwing an active fixation member, provided on the base of the housing of the LIMD, into the tissue of interest, the first and second active electrode areas being located on separate turns of the active fixation member.

15. The method of claim 11, wherein the electrode pair are located on the active fixation member within a distal segment thereof, such that when the active fixation member is installed, the electrode pair are located at or near a surface of the distal wall tissue.

16. The method of claim 11, further comprising securing a pusher tool to a proximal end of the LIMD within the introducer, utilizing the pusher tool to guide the LIMD into position, and utilizing the pusher tool to rotate the LIMD to actively secure a fixation member on the base of the LIMD to a septum.

17. The method of claim 11, further comprising providing a second electrode pair having third and fourth active electrode areas that are provided on a base of the housing, the third and fourth active electrode areas coupled to the sensing circuit and positioned such that the second electrode pair is electrically coupled to the conduction network of the local chamber, the sensing circuit detecting, as near field signals, voltages originating within the conduction network of the local chamber and sensed by the third and fourth active electrode areas, the sensing circuit rejecting, as far field signals, voltages originating within the conduction network of the adjacent chamber and sensed by the third and fourth active electrode areas.

18. The method of claim 11, wherein the active fixation member includes a proximal segment configured to be located at a local sensing site, the method further comprising providing a second electrode pair on the active fixation member in the proximal segment to be electrically coupled to the conduction network of the local chamber, the sensing circuit detecting, as near field signals, voltages originating within the conduction network of the local chamber, the sensing circuit rejecting, as far field signals, voltages originating within the conduction network of the adjacent chamber.

19. The method of claim 11, wherein the active fixation member includes first and second electrode pairs that are located within proximal and distal segments of the active fixation member, respectively, the active electrode areas in the proximal segment being positioned to be electrically coupled to the conduction network of the local chamber.

20. The method of claim 11, further comprising separating the first and second active electrode areas by an inter-electrode spacing such that as depolarization occurs along the distal wall tissue and near field electrical activity moves across the first and second active electrode areas, an associated voltage potential is created between the first and second electrodes, the voltage potential being detected by the sensing circuit as a near field signal.

21. The method of claim 11, further comprising separating the first and second electrodes by an inter-electrode spacing such that as far field electrical activity traverses the first and second active electrode areas, a common mode signal experienced between the first and second active electrode areas, the common mode signal being rejected by the sensing circuit.

22. The method of claim 11, further comprising performing dual chamber pacing and dual chamber sensing.

23. The method of claim 11, further comprising performing sensing only in a right ventricle and pacing in both a right atrium and the right ventricle.