Method and apparatus for identifying oversensing using far-field intracardiac electrograms and marker channels

• US 8,792,971 B2
• Filed: 11/05/2012
• Issued: 07/29/2014
• Est. Priority Date: 04/18/2005
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gunderson, Bruce D., Patel, Amisha S., Bounds, Chad A., Brown, Mark L.
• Primary Examiner(s): Schaetzle, Kennedy
• Application Number:
  US13/668,673
• Publication Number:
  US 20130060117A1
• Time in Patent Office: 631 Days
• Field of Search: None
• US Class Current: 600/518
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• 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 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/3704 Circuits specially adapted therefor, e.g. for sensitivity control

Abstract

A method for identifying oversensing in implantable medical devices (IMDs), such as implantable cardioverter defibrillators (ICDs), is described. A near-field electrogram signal and a far-field electrogram signal are obtained via a near-field electrode pair and a far-field electrode pair. The near-field electrogram signal is compared to the far-field electrogram signal and a determination of whether oversensing exists is made based on the comparison. In some instances, a scheduled therapy is withheld in response to determining that oversensing exists.

Claims

1. An implantable medical system comprising:

at least one implantable lead that includes a plurality of electrodes;

an implantable medical device coupled to the at least one implantable lead, the implantable medical device including;

a memory configured to store a near-field electrogram signal and a far-field electrogam signal; and

a microprocessor configured to obtain the near-field electrogram signal, analyze the near-field electrogram signal to detect sense events in the near-field electrogram signal, obtain the far-field electrogram signal, analyze the far-field electrogram signal to detect sense events in the far-field electrogram signal, map each detected sense event in the far-field electrogram signal to a corresponding detected sense event in the near-field electrogram signal, determine that oversensing exists when a first predetermined number of detected sense events in the near-field electrogram signal that are not mapped to corresponding detected sense events in the far-field electrogram signal occur within a second predetermined number of detected sense events in the near-field electrogram signal that are mapped to corresponding detected sense events in the far-field electrogram signal.

2. The implantable medical system of claim 1, wherein the microprocessor maps each detected sense event in the far-field electrogram signal to a corresponding detected sense event in the near-field electrogram signal that occurs most closely in time.

3. The implantable medical system of claim 1, wherein the microprocessor maps each detected sense event in the far-field electrogram signal to a corresponding detected sense event in the near-field electrogram signal that occurs within plus or minus a predetermined number milliseconds from the detected sense event in the far-field electrogram signal.

4. An implantable medical system comprising:

at least one implantable lead that includes a plurality of electrodes;

an implantable medical device coupled to the at least one implantable lead, the implantable medical device including;

a memory configured to store a near-field electrogram signal and a far-field electrogam signal; and

a microprocessor configured to obtain the near-field electrogram signal, analyze the near-field electrogram signal to detect sense events in the near-field electrogram signal, obtain the far-field electrogram signal, analyze the far-field electrogram signal to detect sense events in the far-field electrogram signal, map each detected sense event in the far-field electrogram signal to a corresponding detected sense event in the near-field electrogram signal, determine a number of detected sense events in the near-field electrogram signal, determine a number of mapped detected sense events in the near-field electrogram signal, compare the total number of detected sense events in the near-field electrogram signal to a threshold value, the threshold value being determined as a function of the number of mapped detected sense events in the near-field electrogram signal, and determine that oversensing exists when the total number of detected sense events in the near-field electrogram signal is greater than the threshold value and a first predetermined number of detected sense events in the near-field electrogram signal that are not mapped to corresponding detected sense events in the far-field electrogram signal occur within a second predetermined number of detected sense events in the near-field electrogram signal that are mapped to corresponding detected sense events in the far-field electrogram signal.

5. A method comprising:

obtaining, with a microprocessor, a near-field electrogram signal;

analyzing the near-field electrogram signal to detect sense events in the near-field electrogram signal;

obtaining, with the microprocessor, a far-field electrogam signal;

analyzing the far-field electrogram signal to detect sense events in the far-field electrogram signal;

mapping, with the microprocessor, each detected sense event in the far-field electrogram signal to a corresponding detected sense event in the near-field electrogram signal; and

determining, with the microprocessor, that oversensing exists when a first predetermined number of detected sense events in the near-field electrogram signal that are not mapped to corresponding detected sense events in the far-field electrogram signal occur within a second predetermined number of detected sense events in the near-field electrogram signal that are mapped to corresponding detected sense events in the far-field electrogram signal.

6. The method of claim 5, wherein mapping each detected sense event in the far-field electrogram signal to a corresponding detected sense event in the near-field electrogram signal comprises mapping, with the microprocessor, each detected sense event in the far-field electrogram signal to a corresponding detected sense event in the near-field electrogram signal that occurs most closely in time.

7. The method of claim 5, wherein mapping each detected sense event in the far-field electrogram signal to a corresponding detected sense event in the near-field electrogram signal comprises mapping, with the microprocessor, each detected sense event in the far-field electrogram signal to a corresponding detected sense event in the near-field electrogram signal that occurs within plus or minus a predetermined number milliseconds from the detected sense event in the far-field electrogram signal.

8. A method comprising:

obtaining, with a microprocessor, a near-field electrogram signal;

analyzing the near-field electrogram signal to detect sense events in the near-field electrogram signal;

obtaining, with the microprocessor, a far-field electrogam signal;

analyzing the far-field electrogram signal to detect sense events in the far-field electrogram signal;

mapping, with the microprocessor, each detected sense event in the far-field electrogram signal to a corresponding detected sense event in the near-field electrogram signal;

determining, with the microprocessor, a number of detected sense events in the near-field electrogram signal;

determining, with the microprocessor, a number of mapped detected sense events in the near-field electrogram signal;

comparing, with the microprocessor, the total number of detected sense events in the near-field electrogram signal to a threshold value, the threshold value being determined as a function of the number of mapped detected sense events in the near-field electrogram signal; and

determining that oversensing exists when the total number of detected sense events in the near-field electrogram signal is greater than the threshold value and a first predetermined number of detected sense events in the near-field electrogram signal that are not mapped to corresponding detected sense events in the far-field electrogram signal occur within a second predetermined number of detected sense events in the near-field electrogram signal that are mapped to corresponding detected sense events in the far-field electrogram signal.