System for the diagnosis and monitoring of coronary artery disease, acute coronary syndromes, cardiomyopathy and other cardiac conditions

• US 7,386,340 B2
• Filed: 03/26/2003
• Issued: 06/10/2008
• Est. Priority Date: 03/26/2002
• Status: Expired due to Fees

• Current Assignee: National Aeronautics and Space Administration US Government As Represented By The Administrator of The
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Arenare, Brian, Schlegel, Todd T.
• Primary Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US10/402,866
• Publication Number:
  US 20040039292A1
• Time in Patent Office: 1,903 Days
• Field of Search: 600/509, 600/523, 600/508, 600/515, 600/517, 600/518, 600/521
• US Class Current: 600/517
• CPC Class Codes: A61B 5/366 Detecting abnormal QRS complex, e.g. widening

Abstract

Cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed and stored in a useful form using a computer. The computer monitor displays various useful information, and in particular graphically displays various permutations of reduced amplitude zones and kurtosis that increase the rapidity and accuracy of cardiac diagnoses. New criteria for reduced amplitude zones are defined that enhance the sensitivity and specificity for detecting cardiac abnormalities.

Claims

1. An electrocardiograph system comprising:

means for sensing a plurality of electrocardiograph signals, the signals comprising cardiac data and a succession of waves;

means for independently identifying the QRS complex in each wave;

means for signal-averaging the QRS complex in each wave;

means for band-pass filtering the signal-averaged QRS complex in a high frequency range thereby deriving high frequency components of the QRS complex, wherein the means for band-pass filtering passes frequencies from 150 Hz to 250 Hz;

means for detecting a reduced amplitude zone within the high frequency components of the QRS complex in each wave relating to cardiac function, the reduced amplitude zone within the high frequency components of the QRS complex comprising RAZ data;

means for relating at least three of the detected reduced amplitude zones in accordance with predetermined criteria to develop cardiac diagnoses; and

means for displaying the cardiac and RAZ data in real time on a monitor.

2. The system of claim 1, wherein the reduced amplitude zone is defined as a region within the high frequency components of the QRS complex lying between two neighboring maxima or minima.

3. The system of claim 1, wherein the reduced amplitude zone is defined as a region within the high frequency components of the QRS complex lying between two neighboring maxima or minima, and wherein a second, smaller local maximum or minimum within the high frequency components of the QRS complex is at least a certain user-selectable percentage of the larger of the maxima or minima.

4. The system of claim 3, wherein the percentage is any percentage between 0% and 100%.

5. The system of claim 1, wherein the reduced amplitude zone is defined as a region within the high frequency components of the QRS complex lying between two neighboring maxima or minima, and wherein the voltage of a second, smaller local maximum within the high frequency components of the QRS complex is at least a certain user-selectable percentage of that of the larger of the maxima or wherein the voltage of a second, smaller local minimum within the high frequency components of the QRS complex is at least a certain user-selectable percentage of that of the larger of the minima.

6. The system of claim 1, further comprising means for analyzing a kurtosis of the high frequency components of the QRS complex and determining the kurtosis below a predetermined minimum.

7. The system of claim 1, wherein the means for sensing a plurality of electrocardiograph signals comprise a plurality of electrodes, and wherein the electrodes are defined in spatial relation to one another.

8. The system of claim 7, wherein the means for relating at least three of the detected reduced amplitude zones, relate the reduced amplitude zones in terms of spatial relation.

9. The system of claim 7, wherein the means for relating includes means for relating all of the detected reduced amplitude zones from the means for detecting.

10. The system of claim 1, further comprising:

means for recording a first set of baseline cardiac and RAZ data; and

means for comparing the first set of baseline cardiac and RAZ data with cardiac and RAZ data captured in real time.

11. The system of claim 10, wherein the means for displaying the cardiac data and the RAZ data in real-time on a monitor includes means for displaying the first set of baseline cardiac and RAZ data along with cardiac and RAZ data captured in real time.

12. The system of claim 1, wherein the means for sensing a plurality of electrocardiograph signals includes CR precordial leads.

13. The system of claim 1, wherein the means for signal-averaging is comprised of:

means for developing a time-varying, signal-averaged template based on the QRS complex in each wave from each of the means of sensing;

means for cross-correlating the QRS complex in each wave in real time from each of the means of sensing with a respective time-varying, signal-averaged template; and

means for accepting or rejecting each QRS complex in each wave based on the means for cross-correlating, wherein accepted QRS complexes are incorporated into the time-varying, signal-averaged template.

14. The system of claim 13 further comprising:

means for recording data, wherein the data are comprised of the signals;

the time-varying, signal-averaged template;

the RAZ data;

or any combination; and

means for indicating likely coronary artery disease, acute coronary syndrome, or other cardiac condition from the recorded data when a reduced amplitude zone is present in each of three or more sensing means, wherein the sensing means are spatially contiguous.

15. The system of claim 13,

wherein the reduced amplitude zone is comprised of an Abboud RAZ, Abboud Percent RAZ, a NASA RAZ, Kurtosis RAZ, or any combination, and

wherein the predetermined criteria are comprised of a predetermined percentage occurrence of the Abboud RAZ, Abboud Percent RAZ, NASA RAZ, Kurtosis RAZ, or any combination within a predetermined number of the accepted QRS complexes from at least one of the plurality of electrocardiograph signals.

16. The system of claim 13,

wherein the reduced amplitude zone is comprised of an Abboud RAZ, Abboud Percent RAZ, a NASA RAZ, Kurtosis RAZ, or any combination, and

wherein the predetermined criteria are comprised of an occurrence of the Abboud RAZ, Abboud Percent RAZ, NASA RAZ, Kurtosis RAZ, or any combination when derived from the final time-varying, signal-averaged template.