Far-field R-wave detection to control atrial pace timing in a dual-chamber leadless pacemaker

• US 9,889,303 B2
• Filed: 10/09/2014
• Issued: 02/13/2018
• Est. Priority Date: 09/08/2014
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Brown, Mark L., Greenhut, Saul E., Jackson, Troy E.
• Primary Examiner(s): MAHMOOD, NADIA AHMAD
• Application Number:
  US14/510,637
• Publication Number:
  US 20160067486A1
• Time in Patent Office: 1,223 Days
• Field of Search: 607 17, 600509
• CPC Class Codes: A61B 5/30 Input circuits therefor
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence
• CPC Class Codes: A61N 1/3704 Circuits specially adapted therefor, e.g. for sensitivity control
• CPC Class Codes: A61N 1/371 Capture, i.e. successful stimulation
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

A method for sensing far-field R-waves in a leadless, intracardiac pacemaker implanted in an atrium of a patient'"'"'s heart may involve sensing an electrical signal generated by the heart with two electrodes and a first sensing channel and/or a second sensing channel of the pacemaker, comparing a first timing marker from the first sensing channel with a second timing marker from the second sensing channel, and either determining that the sensed signal is a P-wave, if the first and second timing markers indicate that the sensed signal was sensed by the first and second sensing channels within a predetermined threshold of time from one another, or determining that the sensed signal is a far-field R-wave, if the sensed signal is sensed by the second sensing channel and not sensed by the first sensing channel.

Claims

1. An implantable leadless pacemaker device, comprising:

a housing;

at least one attachment member on the housing for attaching the pacemaker device to an inner wall of a heart;

only two electrodes, spaced far enough apart from one another to be able to detect P-waves generated by a chamber of the heart in which the pacemaker device is implanted and far-field R-waves in an adjacent chamber of the heart;

a first sensing channel in the housing, configured to sense P-waves detected via the only two electrodes and having a first band-pass filter with a frequency range with a low end of approximately 10 Hz to approximately 40 Hz and a high end of greater than approximately 30 Hz and a low sensitivity threshold of about 1 mV;

a second sensing channel in the housing, configured to sense far-field R-waves and P-waves detected via the only two electrodes and having a second band-pass filter with a frequency range with a low end of approximately 0.5 Hz to approximately 20 Hz and a high end of greater than approximately 20 Hz and a high sensitivity threshold of about 0.15 mV; and

a processor configured to distinguish between P-waves and far-field R-waves based on a comparison between data from the first and second sensing channels and to generate a timing signal for timing atrial pacing therapy delivered by the pacemaker.

2. The device of claim 1, wherein the two electrodes are spaced at least 17 millimeters apart.

3. The device of claim 1, further comprising an analog-to-digital converter configured to convert analog signals detected by the electrodes into digital signals for processing by the sensing channels.

4. The device of claim 1, wherein the sensing channels are located within the processor.

10. The device of claim 1, wherein the processor is configured to distinguish between P-waves and far-field R-waves based on a comparison between timing markers from the first and second sensing channels.

11. The device of claim 10, wherein the processor is configured to determine a sensed waveform corresponds to a P-wave on condition that a timing marker from the first sending channel is matched to a timing marker from the second sensing channel within a particular temporal interval.

12. The device of claim 10, wherein the processor is configured to determine a sensed waveform corresponds to a R-wave on condition that a timing marker from the second sensing channel is unmatched to a timing marker from the first sensing channel.

5. An intracardiac pacemaker system, comprising:

an implantable, leadless, ventricular pacemaker device; and

an implantable, leadless, atrial pacemaker device, comprising;

a housing;

at least one attachment member on the housing for attaching the pacemaker device to an inner wall of a heart;

only two electrodes, spaced far enough apart from one another to be able to detect P-waves generated by an atrium of the heart in which the pacemaker device is implanted and far-field R-waves in an adjacent ventricle of the heart;

a first sensing channel in the housing, configured to sense P-waves detected via the only two electrodes and having a first band-pass filter with a frequency range with a low end of approximately 10 Hz to approximately 40 Hz and a high end of greater than approximately 30 Hz and a low sensitivity threshold of about 1 mV;

a second sensing channel in the housing, configured to sense far-field R-waves and P-waves detected via the only two electrodes and having a second band-pass filter with a frequency range with a low end of approximately 0.5 Hz to approximately 20 Hz and a high end of greater than approximately 20 Hz and a high sensitivity threshold of about 0.15 mV; and

a processor configured to distinguish between P-waves and far-field R-waves based on a comparison between timing markers from the sensing channels and to generate a timing signal for timing atrial pacing therapy delivered by the pacemaker.

6. The system of claim 5, wherein the two electrodes are spaced at least 17 millimeters apart.

7. The system of claim 5, further comprising an analog-to-digital converter configured to convert analog signals detected by the electrodes into digital signals for processing by the sensing channels.

8. The system of claim 5, wherein the sensing channels are located within the processor.

9. An implantable leadless pacemaker device, comprising:

a housing;

at least one attachment member on the housing for attaching the pacemaker device to an inner wall of a heart;

only two electrodes, spaced far enough apart from one another to be able to detect P-waves generated by a chamber of the heart in which the pacemaker device is implanted and far-field R-waves in an adjacent chamber of the heart; and

a processor configured to process data sensed by the two electrodes and convert to digital data to distinguish between P-waves and far-field R-waves, wherein the processor comprises;

a first sensing channel, configured to sense P-waves detected via the only two electrodes and having a first band-pass filter with a frequency range with a low end of approximately 10 Hz to approximately 40 Hz and a high end of greater than approximately 30 Hz and a low sensitivity threshold of about 1 mV; and

a second sensing channel, configured to sense far-field R-waves and P-waves detected via the only two electrodes and having a second band-pass filter with a frequency range with a low end of approximately 0.5 Hz to approximately 20 Hz and a high end of greater than approximately 20 Hz and a high sensitivity threshold of about 0.15 mV,

and wherein the processor is configured to distinguish between P-waves and far-field R-waves based on a comparison between digital data from the first and second sensing channels.