Q-onset ventricular depolarization detection in the presence of a pacemaker

• US 20090112108A1
• Filed: 10/22/2008
• Published: 04/30/2009
• Est. Priority Date: 10/26/2007
• Status: Active Grant

• Current Assignee: Inovise Medical, Inc.
• Original Assignee: Inovise Medical, Inc.
• Inventors: Nelson, Alex T., Arand, Patricia A., Gasperina, Marco Dalla
• Granted Patent: US 9,986,926 B2
• Time in Patent Office: Days
• US Class Current: 600/510
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/33 specially adapted for cooperation with other devices
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 7/026 comprising more than one sound collector

Abstract

A method utilizing computer processing for detecting, within a cardiac cycle, the earliest onset of global, Q-onset, ventricular depolarization in the presence of an operating pacemaker. The method, in general terms, features (a) gathering a plurality of ECG-obtained QRS heart-cycles waveforms, (b) identifying and categorizing of evidences and specific timings therein of intrinsic Q-onset and pacemaker spike events, (c) looking in a single, selected QRS waveform, between specific, defined first and second time marks, for the most significant slope change appearing in that waveform, and (d) designating to be the correct Q-onset that event which immediately precedes that slope change.

Claims

1. A method utilizing computer processing for detecting, within a cardiac cycle, the earliest onset of global, Q-onset, ventricular depolarization in the presence of an operating pacemaker, said method comprising

during a predetermined time span including a plurality of successive, QRS cardiac cycles, gathering both ECG and pacemaker-spike information for, and within, each such cycle,

with respect to each such gathered cardiac cycle, time-locating, identifying and time-position sorting, first to last, each intrinsic Q-onset and each pacemaker-spike event, including specifically identifying each pacemaker-spike event as being one of ventricular or bi-ventricular,

also with regard to each such cardiac cycle, evaluating, with respect a single, selected, QRS waveform, the waveform slope therein from (a) a time just preceding, to (b) a time just following, the mentioned, time-position sorted, first-in-time and last-in-time one of such time-located, identified and sorted events, respectively,

from said slope evaluating, finding the time, in the mentioned, single, selected QRS-waveform, of the first substantial QRS-waveform slope change,

n each cardiac cycle, selecting to be the correct Q-onset therein the time-sorted event in that cycle whose time position most immediately precedes the time of the mentioned, found, first-substantial slope change, and

with respect to each cardiac cycle, maintaining the identity of the selected to-be-correct Q-onset event.

2. The method of claim 1 which further comprises, for each cardiac cycle, further identifying the class of the associated, selected-to-be-correct, Q-onset event as being either an intrinsic event or a pacer event, and giving to the associated cycle, as a cycle class-identity—

either intrinsic or paced—

the same, related class-identity as that of the associated, selected-to-be-correct, Q-onset event—

intrinsic or paced.

3. The method of claim 2 which further comprises, across all cycles gathered during the predetermined time span having the same class-identity, determining the dominant identity—

intrinsic, ventricular or bi-ventricular—

of the selected Q-onset event, and forcing all cycles in a given class of cycles also to have the same, dominant, Q-onset event identity—

intrinsic, ventricular, or bi-ventricular.

4. The method of claim 3 which further comprises providing as output information (a) an association of each pacer spike as being one of atrial, ventricular, first bi-ventricular, or second bi-ventricular, (b) a determination for each cycle as to whether it was initiated intrinsically or with a ventricular pacer spike, and (c) for each cycle, the time of the earliest depolarization as selected between the available intrinsic QRS-onset time, and the time of any available ventricular pacing spike.

5. The method of claim 2 which further comprises providing, as output information relevant to the gathered plurality of successive, QRS cardiac cycles, the times and class identities of all of the selected-to-be-correct Q-onset events.

6. The method of claim 1 which further comprises, (a) providing a pacemaker-spike detector and a computer-based, pacemaker-spike classifier, (b) gathering pacemaker-spike occurrence and time information utilizing the pacemaker-spike detector, (c) supplying such pacemaker-spike occurrence and time information for computer processing via the provided pacemaker-spike classifier, and (d) utilizing the pacemaker-spike classifier to furnish detected pacer-spike classification.

7. The method of claim 6 wherein utilization of the provided pacemaker-spike classifier involves computer-performing of each of the processing steps as set forth hereinabove in the detailed description of Algorithm II.

8. The method of claim 1 which further comprises utilizing a pacemaker programmer to supply the gathered pacemaker-spike information.

9. The method of claim 1, wherein said slope evaluating is performed by computer processing effectively using a line having a length of about 14-milliseconds in duration as a projection on the QRS-waveform time axis of the subject QRS-waveform wherein slope is being evaluated, with both ends of the line lying on that waveform, by moving the line from a first time, which is just before the first-in-time identified intrinsic or spike event, to a second time, which is just after the last-in-time identified intrinsic or spike event, and by noting the magnitude of the slope in existence at points distributed on the subject QRS waveform between the just-mentioned first and second times.