Methods and devices for improved evoked response detection and pacemaker capture management
AssigneePacesetter, Inc.
InventorsAlexander R. Bornzin, Nima Badie, Weiqun Yang
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Abstract
Described herein are leadless pacemakers (LPs) and methods for use therewith. In certain embodiments an LP stores a polarization artifacts template or a capture plus polarization artifacts template in memory of the LP. The LP uses the stored template when performing autocapture and/or other types of capture detection to mitigate adverse effects of electrode polarization. Such embodiments are especially useful where the LP is an atrial LP, but can also be used to other types of LPs, such as a ventricular LP.
Claims21
A leadless pacemaker (LP) configured to be implanted in or on a cardiac chamber of a heart, the LP comprising:
- multiple electrodes;
- a memory;
- a pulse generator configured to deliver, using at least two electrodes of the multiple electrodes, electrical stimulation pulses to the cardiac chamber;
- a sensing circuit configured to sense, using at least two electrodes of the multiple electrodes, an electrogram (EGM) indicative of electrical activity of the heart;
- and
- a controller communicatively coupled to the memory, the pulse generator, and the sensing circuit, the controller configured to:
- cause delivery to the cardiac chamber, using the pulse generator and at least two electrodes of the multiple electrodes, of one or more capturing electrical stimulation pulses having a test pulse energy level that is above a capture threshold;
- produce a capture plus polarization artifacts template based on one or more portions of the sensed EGM within one or more respective windows following when the one or more capturing electrical stimulation pulses was/were delivered;
- save, within a portion of the memory, the capture plus polarization artifacts template corresponding to the test pulse energy level;
- cause delivery to the cardiac chamber, using the pulse generator and at least two electrodes of the multiple electrodes, of one or more pacing electrical stimulation pulses having a pacing pulse energy level that is less than the test pulse energy level;
- determine a difference signal between an evoked response morphology of the sensed EGM and the capture plus polarization artifacts template, wherein the evoked response morphology of the sensed EGM corresponds to one or more portions of the sensed EGM within one or more respective windows following when the one or more pacing electrical stimulation pulses having the pacing pulse energy level was/were delivered;
- and
- determine based on the difference signal whether loss of capture occurred responsive to the one or more pacing electrical stimulation pulses having the pacing energy level that is less than the test pulse energy level.
A method for use by a leadless pacemaker (LP) implanted in or on a cardiac chamber of a heart, wherein the LP includes multiple electrodes and memory, and wherein the LP uses at least two of the multiple electrodes for delivering electrical stimulation pulses to the cardiac chamber and at least two of the multiple electrodes for sensing an electrogram (EGM) indicative of electrical activity of the heart, the method comprising:
- (a) delivering to the cardiac chamber, using at least two of the multiple electrodes, one or more capturing electrical stimulation pulses having a test pulse energy level that is above a capture threshold;
- (b) producing a capture plus polarization artifacts template based on one or more portions of the sensed EGM within one or more respective windows following when the one or more capturing electrical stimulation pulses was/were delivered;
- (c) saving, within a portion of the memory, the capture plus polarization artifacts template corresponding to the test pulse energy level;
- (d) delivering to the cardiac chamber, using at least two of the multiple electrodes, one or more pacing electrical stimulation pulses having a pacing pulse energy level that is less than the test pulse energy level;
- (e) determining a difference signal between an evoked response morphology of the sensed EGM and the capture plus polarization artifacts template, wherein the evoked response morphology of the sensed EGM corresponds to one or more portions of the sensed EGM within one or more respective windows following when the one or more pacing electrical stimulation pulses having the pacing pulse energy level was/were delivered;
- and
- (f) determining based on the difference signal whether loss of capture of the cardiac chamber occurred responsive to the one or more pacing electrical stimulation pulses having the pacing energy level that is less than the test pulse energy level.
Dependencies are inferred from the claim text.