EGM signal acquisition and processing system

• US 6,925,331 B2
• Filed: 09/30/2002
• Issued: 08/02/2005
• Est. Priority Date: 09/30/2002
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Hemming, Michael T., Durose-Schrimpf, Lori, Samuelson, Kent E., Wahlstrand, John D., Heinks, Michael W., Starkson, Ross O.
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US10/261,314
• Publication Number:
  US 20040064059A1
• Time in Patent Office: 1,037 Days
• Field of Search: 607/27, 607/30, 607/32, 607/59, 607/60, 600/509, 600/510, 600/522
• US Class Current: 607/32
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• 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 1/37247 User interfaces, e.g. input or presentation means

Abstract

A system and method for acquiring and processing an EGM signal during a pacing event, wherein a unique converter code is generated upon digitizing of the EGM signal and encrypted in the EGM signal to demarcate a transient event. The system further provides dynamic filtering of the EGM signal and subsequent detection of an intrinsic event signal during the pacing event, from which rhythm events may be diagnosed and classified.

Claims

1. An EGM signal acquisition and processing system, comprising:

means for acquiring an EGM signal during a pacing event;

an analog-to-digital converter capable of converting the EGM signal from an analog a digital form;

means for generating an unique code;

a digital EGM signal encrypted with the unique code, the unique code demarcating a transient event;

a dynamic filter capable of dynamically filtering the EGM signal acquired during the pacing event; and

a detector capable of detecting an intrinsic event signal within the digital EGM signal, wherein the means for dynamic filtering of the EGM signal includes;

means for applying a high-pass pole, the high-pass pole equivalent to about 15-40 Hz, at a beginning of the pacing event for about 150-300 msec;

means for smoothly transitioning from the high-pass pole to a low-pass pole, the low-pass pole equivalent to about 0.1-0.4 Hz, over about 100-300 msec; and

means for maintaining the low-pass pole until a next pacing event.

2. The system of claim 1, wherein the detector includes means for diagnosing rhythm events from the intrinsic event signal and classifying the rhythm events according to cardiac co-morbidities.

3. An EGM signal acquisition and processing system, comprising:

means for acquiring an EGM signal during a pacing event;

an analog-to-digital converter capable of converting the EMG signal from an analog to a digital form;

means for generating an unique code;

a digital EGM signal encrypted with the unique code, the unique code demarcating a transient event;

a non-linear element capable of limiting saturation of standard amplifier and filter operations, the saturation caused by voltage excursions of large transient in the EGM signal acquired during a pacing event;

a dynamic filter capable of dynamically filtering the EGM signal; and

a detector capable of detecting an intrinsic event signal within the digital EGM signal.

4. The system of claim 3, wherein the means for dynamic filtering of the EGM signal includes:

a means for applying a high-pass pole, the high-pass pole equivalent to about 15-40 Hz, at a beginning of the pacing event for about 150-300 msec;

a means for smoothly transitioning from the high-pass pole to a low-pass pole, the low-pass pole equivalent to about 0.1-0.4 Hz, over about 100-300 msec; and

a means for maintaining the low-pass pole until a next pacing event.

5. The system of claim 3, wherein the detector includes means for diagnosing rhythm events from the intrinsic event signal and classifying the rhythm events according to cardiac co-morbidities.

6. A method for EGM signal acquisition and processing, comprising:

acquiring an EGM signal during a pacing event;

using a non-linear element to limit saturation of standard amplifying and filtering operations by voltage excursions caused by large transients in the EGM signal acquired during the pacing event;

dynamically filtering the EGM signal acquired during the pacing event;

digitizing the EGM signal acquired during the pacing event;

generating an unique code;

encrypting the digital EGM signal with the unique code; and

detecting an intrinsic event signal within the dynamically filtered and digitized EGM signal.

7. The method according to claim 6, further comprising:

diagnosing rhythm events from the intrinsic event signal; and

classifying a cardiac co-morbidity according to the diagnosed rhythm events.