Methods and systems for managing fusion and noise in cardiac pacing response classification

• US 8,290,591 B2
• Filed: 06/24/2010
• Issued: 10/16/2012
• Est. Priority Date: 04/28/2005
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Stalsberg, Kevin John, Dong, Yanting, Meyer, Scott A., Voegele, John Michael, Bohn, Derek Daniel, Enrooth, Eric Keith, Foster, Clayton Scott, Yost, David William
• Primary Examiner(s): Bertram, Eric D.
• Application Number:
  US12/822,480
• Publication Number:
  US 20100262207A1
• Time in Patent Office: 845 Days
• Field of Search: 607/27, 607/28
• US Class Current: 607/28
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61N 1/371 Capture, i.e. successful stimulation
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Methods and systems for detecting noise in cardiac pacing response classification processes involve determining that a cardiac response classification is possibly erroneous if unexpected signal content is detected. The unexpected signal content may comprise signal peaks that have polarity opposite to the polarity of peaks used to determine the cardiac response to pacing. Fusion/noise management processes include pacing at a relatively high energy level until capture is detected after a fusion, indeterminate, or possibly erroneous pacing response classification is made. The relatively high energy pacing pulses may be delivered until capture is detected or until a predetermined number of paces are delivered.

Claims

1. A method for managing fusion, indeterminate or erroneous pacing responses, comprising:

delivering a first pacing pulse to a heart during a capture threshold test for determining a capture threshold of the heart;

sensing a cardiac response associated with the first pacing pulse;

delivering one or more pacing pulses to the heart at a higher energy level that is expected to capture the heart if the cardiac response associated with the first pacing pulse is determined to be at least one of fusion, indeterminate, and erroneous;

classifying one or more cardiac responses respectively associated with the one or more pacing pulses delivered at the higher energy level that is expected to capture the heart as at least one of capture, fusion, indeterminate and erroneous;

continuing to deliver the one or more pacing pulses at the higher energy level that is expected to capture the heart if each of the one or more cardiac responses is classified as at least one of fusion, indeterminate, and erroneous, and wherein the capture threshold test is terminated if none of a predetermined number of the one or more pacing pulses delivered at the higher energy level that is expected to capture the heart produces the capture response.

2. The method of claim 1, further comprising terminating delivery of the one or more pacing pulses at the higher energy level that is expected to capture the heart if a cardiac response associated with at least one of the one or more pacing pulses is classified as the capture response.

3. The method of claim 1, wherein continuing to deliver the one or more pacing pulses at the higher energy level that is expected to capture the heart comprises, if the cardiac response associated with at least one of the one or more pacing pulses is classified as capture, classifying a cardiac response previous to the capture response as fusion.

4. The method of claim 1, wherein if a cardiac response associated with at least one of the one or more pacing pulses is classified as capture, delivering a next pacing pulse at a scheduled pacing energy that is lower than the pacing energy that is expected to capture the heart.

5. A method for managing fusion, indeterminate or possibly erroneous pacing responses, comprising:

delivering a first pacing pulse to a heart chamber;

delivering one or more pacing pulses to the heart chamber if a cardiac response associated with the first pacing pulse is at least one of fusion, indeterminate, and possibly erroneous, the one or more pacing pulses having a pacing energy greater than the first pacing pulse;

determining one or more cardiac responses respectively associated with the one or more pacing pulses;

continuing to deliver the one or more pacing pulses if each of the one or more cardiac responses is at least one of fusion, indeterminate, and possibly erroneous or until a predetermined number of the one or more pacing pulses has been delivered; and

determining that a sensing channel for sensing the cardiac responses is unacceptably noisy if none of the predetermined number of the one or more pacing pulses produces a capture response.

6. A cardiac rhythm management device, comprising:

a pulse generator configured to deliver pacing pulses to a heart;

a sensing circuit configured to sense cardiac signals of the heart, the sensed cardiac signals respectively associated with the pacing pulses; and

a processor coupled to the sensing circuit and the pulse generator, the processor configured to perform a capture threshold test for determining a capture threshold of the heart including delivering a first pacing pulse to the heart, and to receive a sensed signal from the sensing circuit indicative of a cardiac response associated with at least the first pacing pulse, deliver one or more pacing pulses having a pacing energy greater than the first pacing pulse and that is expected to capture the heart if a cardiac response associated with the first pacing pulse is determined to be at least one of fusion, indeterminate, and erroneous, classify one or more cardiac responses respectively associated with the one or more pacing pulses delivered at the pacing energy greater than the first pacing pulse and that is expected to capture the heart, and to continue to deliver the one or more pacing pulses at the pacing energy greater than the first pacing pulse and that is expected to capture the heart if each of the one or more cardiac responses is classified as at least one of fusion, indeterminate, and erroneous, and to terminate the capture threshold test if none of a predetermined number of the one or more pacing pulses having a pacing energy greater than the first pacing pulse and that is expected to produce capture produces a capture response.

7. The device of claim 6, wherein the processor is configured to terminate delivery of the one or more pacing pulses having pacing energy greater than the first pacing pulse and that is expected to capture the heart if a cardiac response associated with at least one of the one or more pacing pulses is classified as capture.

8. The device of claim 6, wherein the processor is configured to classify a cardiac response produced previous to a capture response as fusion if the cardiac response associated with at least one of the one or more pacing pulses having a pacing energy greater than the first pacing pulse and that is expected to capture the heart is classified as capture.

9. A cardiac rhythm management device, comprising:

a pulse generator configured to deliver pacing pulses to a heart chamber;

a sensing circuit configured to sense cardiac signals of the heart chamber, the sensed cardiac signals respectively associated with the pacing pulses;

a processor coupled to the sensing circuit and the pulse generator, the processor configured to deliver a first pacing pulse to the heart chamber, deliver one or more pacing pulses having a pacing energy greater than the first pacing pulse to the heart chamber if a cardiac response associated with the first pacing pulse is at least one of fusion, indeterminate, and possibly erroneous, determine one or more cardiac responses respectively associated with the one or more pacing pulses, and continue to deliver the one or more pacing pulses if each of the one or more cardiac responses is at least one of fusion, indeterminate, and possibly erroneous; and

wherein the processor is configured to continue to deliver the one or more pacing pulses until a predetermined number of the one or more pacing pulses has been delivered, and to determine that a sensing channel for sensing the cardiac responses is unacceptably noisy if none of the predetermined number of the one or more pacing pulses produces a capture response.

10. A cardiac rhythm management system for managing fusion, indeterminate or erroneous pacing responses, the system comprising:

means for determining that a cardiac response associated with a first pacing pulse delivered during a capture threshold test for determining a capture threshold of a heart is at least one of fusion, indeterminate, and erroneous;

means for delivering one or more pacing pulses having a pacing energy greater than that of the first pacing pulse and that is expected to capture the heart if the cardiac response associated with the first pacing pulse is determined to be at least one of fusion, indeterminate, and erroneous;

means for classifying a cardiac response associated with each of the one or more pacing pulses;

means for continuing to deliver the one or more pacing pulses having the pacing energy greater than that of the first pacing pulse if the cardiac response associated with each of the one or more pacing pulses is classified as at least one of fusion, indeterminate, and erroneous; and

means for terminating the capture threshold test if none of a predetermined number of the one or more pacing pulses having a pacing energy greater than that of the first pacing pulse produces a capture response.

11. The system of claim 10, wherein the means for terminating delivery of the one or more pacing pulses terminates the capture threshold test if a cardiac response associated with at least one of the one or more pacing pulses is classified as capture.

12. The system of claim 10, wherein the means for continuing continues to deliver the one or more pacing pulses at the pacing energy greater than the first pacing pulse until a predetermined number of pacing pulses have been delivered.