System and method for sensing and detecting far-field R-wave

• US 6,526,311 B2
• Filed: 07/30/2001
• Issued: 02/25/2003
• Est. Priority Date: 08/11/2000
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Begemann, Malcolm J.
• Primary Examiner(s): Bockelman, Mark
• Application Number:
  US09/916,457
• Publication Number:
  US 20020040191A1
• Time in Patent Office: 575 Days
• Field of Search: 600/509, 600/521
• US Class Current: 600/509
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/29 for permanent or long-term implantation
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371

Abstract

An improved system and method for analyzing far-filed R-waves detected by a sensing device located in the atrium of a patient'"'"'s heart are provided.

Claims

1. A method for detecting cardiac far-field R-waves using an implatable medical device, comprising:

sensing a ventricular event or pacing the ventricular event;

recording atrial events including at least a past atrial event, a current atrial event, and a next atrial event;

measuring a first time interval between the ventricular event and the current atrial event;

measuring a second time interval between the past atrial event and the current atrial event;

measuring a third time interval between the current atrial event and the next atrial event;

calculating whether the first time interval is less than a predetermined first time interval amount;

determining a first criteria for potential far-field R-waves if the first time interval is less than the predetermined first time interval amount;

calculating whether the second time interval differs from the third time interval by a predetermined interval amount;

determining a second criteria for potential far-field R-waves is met if the second time interval differs from the third time interval by the predetermined interval amount;

calculating the number of first time intervals that are substantially constant in duration;

determining a third criteria for potential far-field R-waves is met if there are at least two substantially constant first time intervals; and

,

deciding that there are far-field R-waves if the first criteria, second criteria, and third criteria are met.

2. The method as in claim 1, further comprising,

calculating whether the second time interval midpoint occurs within a post-ventricular atrial blanking period;

determining a fourth criteria for potential far-field R-waves is met if the second time interval midpoint does not occur within the post-ventricular atrial blanking period; and

,

deciding that there are far-field R-waves if the first criteria, second criteria, third criteria, and fourth criteria are met.

3. The method as in claim 1, wherein the predetermined first time interval amount is adjusted once far-field R-waves are confirmed.

4. The method as in claim 1, wherein once the third criteria for potential far-field R-waves is met, additional first time intervals fulfilling the first criteria and the second criteria will be determined to be far-field R-waves if the additional time intervals are substantially the same as the at least two substantially constant first time intervals.

5. The method as in claim 1, wherein the first time interval predetermined amount is adjusted once far-field R-waves are confirmed.